Arterial supply of head & neck

Arterial supply of head & neckArterial supply of head & neck

THE EXTERNAL CAROTID ARTERYTHE EXTERNAL CAROTID ARTERY
 Course :Course :
 It begins at the bifurcation of theIt begins at the bifurcation of the
common carotid artery opposite thecommon carotid artery opposite the
appear border of the thyroid cartilage,appear border of the thyroid cartilage,
and ascending upwards it at first liesand ascending upwards it at first lies
deep to and then within thedeep to and then within the
substances of the parotid gland andsubstances of the parotid gland and
ends by dividing into maxillary (internalends by dividing into maxillary (internal
maxillary) and superficial temporalmaxillary) and superficial temporal
arteries opposite the level of the neckarteries opposite the level of the neck
of the mandibleof the mandible
 Branches of the external carotidBranches of the external carotid
artery :artery :
1.1. Superior thyroidSuperior thyroid
2.2. Ascending pharyngealAscending pharyngeal
3.3. LingualLingual
4.4. FacialFacial
5.5. OccipitalOccipital
6.6. Posterior auricularPosterior auricular
7.7. Superficial temporalSuperficial temporal
8.8. Maxillary.Maxillary.

 Relation :Relation : Opposite the angle of the mandible it isOpposite the angle of the mandible it is
covered superficially by the posterior belly of thecovered superficially by the posterior belly of the
digastric and the stylohyoid muscles. Between its origindigastric and the stylohyoid muscles. Between its origin
and the posterior belly of digastric it is comparativelyand the posterior belly of digastric it is comparatively
superficial being overlapped only by the anterior marginsuperficial being overlapped only by the anterior margin
of the sternocleidomastoid. It is crossed superficially byof the sternocleidomastoid. It is crossed superficially by
the (common) facial vein and the hypoglossal nerve inthe (common) facial vein and the hypoglossal nerve in
this situation. Above the angle of the mandible it at firstthis situation. Above the angle of the mandible it at first
lies posterior to the parotid gland and then embeddedlies posterior to the parotid gland and then embedded
into its substance. Medially it is related to the middle andinto its substance. Medially it is related to the middle and
inferior constrictor muscles of the pharynx and theinferior constrictor muscles of the pharynx and the
external and the internal laryngeal nerves.external and the internal laryngeal nerves.
Posterolaterally it is related to the internal carotid artery.Posterolaterally it is related to the internal carotid artery.

Arterial supply of head & neckArterial supply of head & neck
 INTRODUCTIONINTRODUCTION
 ANGIOGENESISANGIOGENESIS
 STRUCTURE OF ARTERIESSTRUCTURE OF ARTERIES
 GROWTH OF BLOOD VESSELSGROWTH OF BLOOD VESSELS
 A NOTE ON ANASTOMOSIS ANDA NOTE ON ANASTOMOSIS AND
COLATERAL CIRCULATION.COLATERAL CIRCULATION.
 FUNCTION OF ARTERIAL WALLFUNCTION OF ARTERIAL WALL
 Maintenance of blood flow and BPMaintenance of blood flow and BP
in diastolein diastole
 Propulsion of blood throughPropulsion of blood through
coronary arteries.coronary arteries.
 Constriction and dilation of vessels.Constriction and dilation of vessels.
 EXAMINATION OF BLOOD VESSELSEXAMINATION OF BLOOD VESSELS
 Clinical examination arteriesClinical examination arteries
 X-ray examination of blood vesselsX-ray examination of blood vessels
(Angiography)(Angiography)
 ARTERIES OF BODYARTERIES OF BODY
 Arteries of pulmonary circulationArteries of pulmonary circulation
 Arteries of systemic circulation.Arteries of systemic circulation.
 AORTAAORTA
 Arch of aorta and its branchesArch of aorta and its branches
 Varation in branching patternVaration in branching pattern
 Common carotid arteryCommon carotid artery
 Surface anatomySurface anatomy
 Course and relationsCourse and relations
 DevelopmentsDevelopments
 Carotid bodyCarotid body
 Applied surgical anatomy.Applied surgical anatomy.
 External carotid arteryExternal carotid artery

SUPERIOR THYROID ARTERYSUPERIOR THYROID ARTERY
 LINGUAL ARTERYLINGUAL ARTERY
 FACIAL ARTERYFACIAL ARTERY
 OCCIPITAL ARTERYOCCIPITAL ARTERY
 ASCENDING PHARYNGEAL ARTERYASCENDING PHARYNGEAL ARTERY
 POSTERIOR AURICULAR ARTERYPOSTERIOR AURICULAR ARTERY
 SUPERFICIAL TEMPORALSUPERFICIAL TEMPORAL
 MAXILLARY ARTERYMAXILLARY ARTERY
 INTERNAL CAROTID ARTERYINTERNAL CAROTID ARTERY
 APPLIED SURGICAL ASPECTAPPLIED SURGICAL ASPECT
 CAROTID ARTERY LIGATIONCAROTID ARTERY LIGATION
 Indication selective carotidIndication selective carotid
resectionresection
 EvaluationEvaluation
 Carotid ligation –Carotid ligation –
operative and perioperativeoperative and perioperative
managementmanagement
 Alternatives to carotid ligationAlternatives to carotid ligation
 Prevention of carotid rupturePrevention of carotid rupture
 Management of spontaneous carotidManagement of spontaneous carotid
rupturerupture
 Neck incision or carotid ruptureNeck incision or carotid rupture
 Prevention of carotid blow outPrevention of carotid blow out
 SUBCLAVIAN ARTERYSUBCLAVIAN ARTERY
VERTEBRAL ARTERYVERTEBRAL ARTERY
 RADITION EFFECTS ON ARTERIESRADITION EFFECTS ON ARTERIES
 AGE CHANGES IN ARTERIESAGE CHANGES IN ARTERIES
 REFERENCESREFERENCES

IntroductionIntroduction
 A successful out come of major head and neck surgery depends greatly onA successful out come of major head and neck surgery depends greatly on
prevention of two major causes.prevention of two major causes.
 Intra-operative and post operative, morbidity and mortality “Hemorrhage”Intra-operative and post operative, morbidity and mortality “Hemorrhage”
 Airway obstruction.Airway obstruction.
 Frequently these two entities are interrelated. As every one knows “Prevention isFrequently these two entities are interrelated. As every one knows “Prevention is
better than cure”.better than cure”.
 Prevention of hemorrhage depends on thePrevention of hemorrhage depends on the
 Meticulous surgical techniqueMeticulous surgical technique
 Through knowledge of head and neck anatomyThrough knowledge of head and neck anatomy
 Proper preoperative evaluation of the coagulation factors essential for properProper preoperative evaluation of the coagulation factors essential for proper
homeostasis.homeostasis.
 If hemorrhagic complication are anticipated and prevented, most major bleedingIf hemorrhagic complication are anticipated and prevented, most major bleeding
complication can be avoided.complication can be avoided.
 The heart provides the major force that cause blood to circulate but the blood vesselsThe heart provides the major force that cause blood to circulate but the blood vessels
carry blood to all tissue of the body and back to the heart. In addition, the bloodcarry blood to all tissue of the body and back to the heart. In addition, the blood
vessels participate in the regulation of blood pressure and help to direct blood flow tovessels participate in the regulation of blood pressure and help to direct blood flow to
tissue that are most active. The intricacy and coordinated function of blood vesselstissue that are most active. The intricacy and coordinated function of blood vessels
make the design of complex urban water system seem rather simple in comparison.make the design of complex urban water system seem rather simple in comparison.
 The peripheral circulatory system can be divided into two sets of blood vessels. TheThe peripheral circulatory system can be divided into two sets of blood vessels. The
systemic vessels transport blood through essentially, all parts of the body from the leftsystemic vessels transport blood through essentially, all parts of the body from the left
ventricle and back to right atrium. The pulmonary verses. Transport blood from rightventricle and back to right atrium. The pulmonary verses. Transport blood from right
ventricle through lung and back to the left atrium. The cardiovascular system ensuresventricle through lung and back to the left atrium. The cardiovascular system ensures
the survival of each tissue type in the body by supplying nutrients and removingthe survival of each tissue type in the body by supplying nutrients and removing
waste products from tissues.waste products from tissues.

ANGIONESIS :ANGIONESIS :
 When pharyngeal arches form during 4th and 5th week of development,When pharyngeal arches form during 4th and 5th week of development,
each arch receives its own cranial nerve and its own artery. These arteries,each arch receives its own cranial nerve and its own artery. These arteries,
the artic arches and from the aortic sac, the most distal part of the truncusthe artic arches and from the aortic sac, the most distal part of the truncus
arteriosus. The aortic arches are embedded in mesenchyme of pharyngealarteriosus. The aortic arches are embedded in mesenchyme of pharyngeal
arch and terminate in the right and left dorsal aortic. (In the region of thearch and terminate in the right and left dorsal aortic. (In the region of the
arches the dorsal aortae, remain paired, but caudal to this region they fusearches the dorsal aortae, remain paired, but caudal to this region they fuse
to form a single vessel).to form a single vessel).
 The aortic sac contributes a branch to each new arch as it form giving riseThe aortic sac contributes a branch to each new arch as it form giving rise
to a total of 5 pairs of arteries. (The 5th arch either never forms or formsto a total of 5 pairs of arteries. (The 5th arch either never forms or forms
incompletely and then regresses.incompletely and then regresses.
 Division of the truncus arteriosus by aortic pulmonary septum divides theDivision of the truncus arteriosus by aortic pulmonary septum divides the
outflow channel of the heart into ventral aorta and the pulmonary artery. Theoutflow channel of the heart into ventral aorta and the pulmonary artery. The
aortic sac then forms right and left horns, which subsequently give rise toaortic sac then forms right and left horns, which subsequently give rise to
branchiocephalic artery and the proximal. Segment of aortic archbranchiocephalic artery and the proximal. Segment of aortic arch
respectively.respectively.
 By day 27, most of the 1st aortic arch, has disappeared although a smallBy day 27, most of the 1st aortic arch, has disappeared although a small
portion persist to form maxillary artery.portion persist to form maxillary artery.
 Similarly, the second aortic arch disappear. The remaining portion of thisSimilarly, the second aortic arch disappear. The remaining portion of this
arch are, hyoid and stapedial arteries .arch are, hyoid and stapedial arteries .
 The 3rd arch is large; the 4th and 6th arches are in the process of formation.The 3rd arch is large; the 4th and 6th arches are in the process of formation.
Even though the 6th arch is not completed, the primitive pulmonary artery isEven though the 6th arch is not completed, the primitive pulmonary artery is
already prevent as a major branch.already prevent as a major branch.

 The third aortic arch forms the common carotid artery and the 1stThe third aortic arch forms the common carotid artery and the 1st
part of the internal carotid artery. The remainder, of the internalpart of the internal carotid artery. The remainder, of the internal
carotid artery is formed by cranial portion of the dorsal aorta.carotid artery is formed by cranial portion of the dorsal aorta.
 The external carotid artery is a sprout of the 3rd aortic arch.The external carotid artery is a sprout of the 3rd aortic arch.
 The 4th arch persists on both sides but it’s ultimate fate in differentThe 4th arch persists on both sides but it’s ultimate fate in different
on the right and left side.on the right and left side.
 On left – If forms part of arch of aorta between the left. CommonOn left – If forms part of arch of aorta between the left. Common
carotid and the left subclavian arteries.carotid and the left subclavian arteries.
 On right – It forms the most proximal segment of the right subclavianOn right – It forms the most proximal segment of the right subclavian
artery.artery.
 5th arch either never forms or forms incompletely and then5th arch either never forms or forms incompletely and then
regresses.regresses.
 The vascular system, is both a conduit for the flowing blood and aThe vascular system, is both a conduit for the flowing blood and a
dynamic system that control the distribution of blood in the body.dynamic system that control the distribution of blood in the body.
 The elastic arteries dampen the pulsatile outflow of the blood fromThe elastic arteries dampen the pulsatile outflow of the blood from
the heart to provide a more continuous flow of blood to the tissue.the heart to provide a more continuous flow of blood to the tissue.
The arterioles, because of their smaller internal diameter, are theThe arterioles, because of their smaller internal diameter, are the
major site of resistance of blood flow changes in the diameter ofmajor site of resistance of blood flow changes in the diameter of
arterioles determine the amount of blood flowing. Through aarterioles determine the amount of blood flowing. Through a
particular tissue bed .particular tissue bed .

STRUCTURE OF THE ARTERIESSTRUCTURE OF THE ARTERIES::
 In the arteries the primary coat of endothelium, together with a supporting subIn the arteries the primary coat of endothelium, together with a supporting sub
endothelial layer of elastic tissue, is known as the inner tunic or tunica intima. Theendothelial layer of elastic tissue, is known as the inner tunic or tunica intima. The
secondary coat is subdivided into the middle (tunica media) and outer (tunica externasecondary coat is subdivided into the middle (tunica media) and outer (tunica externa
or adventitia) tunics. The tunica externa consists chiefly of fibrous tissue, but theor adventitia) tunics. The tunica externa consists chiefly of fibrous tissue, but the
media is composed of both muscle and elastic tissue, combined in varyingmedia is composed of both muscle and elastic tissue, combined in varying
proportions in different parts of the arterial tree. In the larger arteries the tunica mediaproportions in different parts of the arterial tree. In the larger arteries the tunica media
is mainly elastic, in the medium-sized arteries elastic and muscular elements areis mainly elastic, in the medium-sized arteries elastic and muscular elements are
evenly mixed, while in the smaller arteries the media is predominantly muscular.evenly mixed, while in the smaller arteries the media is predominantly muscular.
 Tunica intima :Tunica intima :
This consists of endothelium, surrounded by the internal elastic lamina, a thick sheetThis consists of endothelium, surrounded by the internal elastic lamina, a thick sheet
of elastic tissue which in histological section has a characteristic wavy appearance.of elastic tissue which in histological section has a characteristic wavy appearance.
This appearance is in all probability due to the post-mortem contraction of the vessel,This appearance is in all probability due to the post-mortem contraction of the vessel,
for it disappears to a considerable extent when the arteries are fully dilated.for it disappears to a considerable extent when the arteries are fully dilated.
 Tunica media :Tunica media :
The elastic tissue in the media is in the form of numerous separate sheets,The elastic tissue in the media is in the form of numerous separate sheets,
concentrically arranged and overlapping one another. In transverse the internalconcentrically arranged and overlapping one another. In transverse the internal
sections these sheets are cut end no, and appear as wavy lines, thinner than elasticsections these sheets are cut end no, and appear as wavy lines, thinner than elastic
lamina.lamina.
Smooth muscle fibers are found in the tunica media. They have usually been thoughtSmooth muscle fibers are found in the tunica media. They have usually been thought
to surround the vessel at right-angles to its long axis, and have therefore been calledto surround the vessel at right-angles to its long axis, and have therefore been called
circular; but not infrequently they are arranged in the form of spirals. In the largercircular; but not infrequently they are arranged in the form of spirals. In the larger
arteries there is but little muscle present; as the arteries divide, muscle fibers appeararteries there is but little muscle present; as the arteries divide, muscle fibers appear
in increasing numbers, while elastic tissue diminishes. In the smaller arteries andin increasing numbers, while elastic tissue diminishes. In the smaller arteries and
arterioles the media is almost exclusively muscular.arterioles the media is almost exclusively muscular.

 Tunica externa or adventitia :Tunica externa or adventitia :
The outermost tunic consists mainly of connective tissues whoseThe outermost tunic consists mainly of connective tissues whose
collagen fibers, particularly in the large arteries, impart great tensilecollagen fibers, particularly in the large arteries, impart great tensile
strength and so prevent excessive vasodilatation.strength and so prevent excessive vasodilatation.
The artery with its three coats lies embedded in the surroundingThe artery with its three coats lies embedded in the surrounding
connective tissue, which varies in different parts of the body both inconnective tissue, which varies in different parts of the body both in
density and in extent to which the adventitia is attached to it. Indensity and in extent to which the adventitia is attached to it. In
some regions the adventitia is surrounded by dense connectivesome regions the adventitia is surrounded by dense connective
tissue to which it is very closely attached. The artery is therebytissue to which it is very closely attached. The artery is thereby
firmly anchored in position, and when cut cannot retract, since thefirmly anchored in position, and when cut cannot retract, since the
cut end is kept fixed and gaping wide open. Bleeding from suchcut end is kept fixed and gaping wide open. Bleeding from such
arteries is therefore particularly free; the arteries of the scalp andarteries is therefore particularly free; the arteries of the scalp and
the palm of the and are of this type.the palm of the and are of this type.
In the larger arteries the adventitia may form a loosely attachedIn the larger arteries the adventitia may form a loosely attached
sheath which was been aptly compared to the outer tube ofsheath which was been aptly compared to the outer tube of
pneumatic tyre. In this sheath the blood vessels and nerves of thepneumatic tyre. In this sheath the blood vessels and nerves of the
artery first ramify before they enter the media; the diffuse network ofartery first ramify before they enter the media; the diffuse network of
nerve fibers in the adventitia is the periarterial plexus. Stripping thenerve fibers in the adventitia is the periarterial plexus. Stripping the
adventitia cuts off the nerve supply of the subjacent portion of theadventitia cuts off the nerve supply of the subjacent portion of the
artery, and constitutes the operation of periarterial sympathectomy.artery, and constitutes the operation of periarterial sympathectomy.
The network of blood vessels in the adventitia, and the fineThe network of blood vessels in the adventitia, and the fine
branches which they give to, and receive from, the tunica media,branches which they give to, and receive from, the tunica media,
constitute the vasa vasorum.constitute the vasa vasorum.

FUNCTION OF THE ARTERIAL WALLFUNCTION OF THE ARTERIAL WALL ::
 Maintenance of blood flow and blood pressure in diastole:Maintenance of blood flow and blood pressure in diastole:
When the ventricle contract, the force of their contraction is expended partlyWhen the ventricle contract, the force of their contraction is expended partly
in driving blood through the arteries, and partly in stretching the elasticin driving blood through the arteries, and partly in stretching the elastic
tissue in their walls. A pressure wave, expending the elastic vessel walls,tissue in their walls. A pressure wave, expending the elastic vessel walls,
passes peripherally at high speed, and the distension of the wall ispasses peripherally at high speed, and the distension of the wall is
perceptible as the pulse wave. During diastole the stretched elastic tissueperceptible as the pulse wave. During diastole the stretched elastic tissue
recoils on the contained blood, and produces a pressure which first closesrecoils on the contained blood, and produces a pressure which first closes
the aortic and pulmonary valves, thus preventing the backflow of blood intothe aortic and pulmonary valves, thus preventing the backflow of blood into
the relaxed ventricles, and then drives the blood forward through thethe relaxed ventricles, and then drives the blood forward through the
arteries. By providing a driving force for the blood during diastole, the elasticarteries. By providing a driving force for the blood during diastole, the elastic
tissue of the arteries converts into a continuous flow one which wouldtissue of the arteries converts into a continuous flow one which would
otherwise be intermittent.otherwise be intermittent.
 Propulsion of blood through the coronary arteries:Propulsion of blood through the coronary arteries:
The elastic recoil of the aorta also serves to drive blood through theThe elastic recoil of the aorta also serves to drive blood through the
coronary arteries to supply the heart. The coronary arteries arise from thecoronary arteries to supply the heart. The coronary arteries arise from the
aorta close to its origin from the left ventricle and their terminal branchesaorta close to its origin from the left ventricle and their terminal branches
ramify among the cardiac muscle fibers; ventricular contraction compressesramify among the cardiac muscle fibers; ventricular contraction compresses
these branches and impedes the flow of blood through them. It is only whenthese branches and impedes the flow of blood through them. It is only when
the musculature of the ventricle is relaxed that blood can flow freely throughthe musculature of the ventricle is relaxed that blood can flow freely through
the coronary vessels, and the drives force, for this flow is the elastic recoil ofthe coronary vessels, and the drives force, for this flow is the elastic recoil of
aorta and larger arteries. If the elasticity of the aorta and its main branchesaorta and larger arteries. If the elasticity of the aorta and its main branches
is diminished, the immediate result will be lowering of the diastolic pressure,is diminished, the immediate result will be lowering of the diastolic pressure,
and a diminution in the amount of blood flowing through the coronaryand a diminution in the amount of blood flowing through the coronary
arteries.arteries.

 Constriction and dilatation of arteries:Constriction and dilatation of arteries:
Contraction of the circular muscle fibers narrows the vessel, and if blood pressure and rate ofContraction of the circular muscle fibers narrows the vessel, and if blood pressure and rate of
flow are unchanged, this diminishes the volume of blood flowing through it in a given time.flow are unchanged, this diminishes the volume of blood flowing through it in a given time.
Narrowing of a vessel is termed vasoconstriction, and widening is vasodilatation. By means ofNarrowing of a vessel is termed vasoconstriction, and widening is vasodilatation. By means of
vasoconstriction and vasodilatation the flow of blood to part can be accurately regulated, invasoconstriction and vasodilatation the flow of blood to part can be accurately regulated, in
accordance with its functional needs.accordance with its functional needs.
The caliber of an artery at any given moment represents a balance between two opposing forces,The caliber of an artery at any given moment represents a balance between two opposing forces,
one being the fluid pressure of the blood in the lumen, exerted outwards in all directions andone being the fluid pressure of the blood in the lumen, exerted outwards in all directions and
dilating the vessel, the other the contraction of the circular muscle, constricting the vessel. Indilating the vessel, the other the contraction of the circular muscle, constricting the vessel. In
large arteries with but little muscle the tension of the elastic tissue has the same effect as musclelarge arteries with but little muscle the tension of the elastic tissue has the same effect as muscle
contraction, except that it obeys purely mechanical laws and is not under nervous control. Allcontraction, except that it obeys purely mechanical laws and is not under nervous control. All
arteries with muscle fibers in their wall receive a vasomotor nerve supply, through which the tonearteries with muscle fibers in their wall receive a vasomotor nerve supply, through which the tone
or the degree of contraction of these fibers can be regulated.or the degree of contraction of these fibers can be regulated.
Most of the vasomotor nerves are vasoconstrictor. When they are stimulated, contraction of theMost of the vasomotor nerves are vasoconstrictor. When they are stimulated, contraction of the
circular muscle occurs and vasoconstriction ensues. When the stimulation ceases, the musclecircular muscle occurs and vasoconstriction ensues. When the stimulation ceases, the muscle
fibers relax and become stretched by the pressure of the blood in the lumen, so thefibers relax and become stretched by the pressure of the blood in the lumen, so the
vasodilatation occurs. This vasodilatation is therefore passively produced, by cutting off allvasodilatation occurs. This vasodilatation is therefore passively produced, by cutting off all
impulses passing along the vasoconstrictor nerves, as there is a tonic discharge in theseimpulses passing along the vasoconstrictor nerves, as there is a tonic discharge in these
vasoconstrictor adrenergic fibers. In addition to these vasoconstrictor fibers, the skeletal bloodvasoconstrictor adrenergic fibers. In addition to these vasoconstrictor fibers, the skeletal blood
vessels are innervated by vasodilator fibers which are cholinergic. But vasodilatation can also bevessels are innervated by vasodilator fibers which are cholinergic. But vasodilatation can also be
produced in a more active manner, by actually stimulating certain nerves. These vasodilatorproduced in a more active manner, by actually stimulating certain nerves. These vasodilator
nerves are much less numerous than the vasoconstrictor, and their existence was establishednerves are much less numerous than the vasoconstrictor, and their existence was established
some time after that of the latter. They probably act by inhibiting and causing still furthersome time after that of the latter. They probably act by inhibiting and causing still further
relaxation of the circular muscle, for there are no specially disposed muscle fibers which could,relaxation of the circular muscle, for there are no specially disposed muscle fibers which could,
by their contraction, actively dilate the artery. The obvious arrangement for vasodilator fibersby their contraction, actively dilate the artery. The obvious arrangement for vasodilator fibers
would be a radial one, the fibers passing from the outer circumference of the vessel towards thewould be a radial one, the fibers passing from the outer circumference of the vessel towards the
tunica intima; but as has already been pointed out, there are no radial fibers present. Antunica intima; but as has already been pointed out, there are no radial fibers present. An
instructive comparison may be made with the pupil, where it is also necessary to be able toinstructive comparison may be made with the pupil, where it is also necessary to be able to
enlarge or to narrow a circular aperture. In the pupil there is no completely enclosed fluid underenlarge or to narrow a circular aperture. In the pupil there is no completely enclosed fluid under
pressure to act as a dilator, and therefore two sets of muscle fibers are required, circular topressure to act as a dilator, and therefore two sets of muscle fibers are required, circular to
constrict, and a radial to dilate. The radial fibers may be for the most part elastic and notconstrict, and a radial to dilate. The radial fibers may be for the most part elastic and not
muscular, but this does not invalidate the comparison with the arteries, in which no radiallymuscular, but this does not invalidate the comparison with the arteries, in which no radially
arranged dilator elements are needed, since their place is taken by the blood pressure whicharranged dilator elements are needed, since their place is taken by the blood pressure which
provides a dilating force form within.provides a dilating force form within.

 Changes after injury to vessel wall:Changes after injury to vessel wall:
The presence of elastic tissue determines some of theThe presence of elastic tissue determines some of the
changes which take place in an artery after injury. if anchanges which take place in an artery after injury. if an
artery of completely severed the cut ends usually retract,artery of completely severed the cut ends usually retract,
sometimes for a considerable distance. This can besometimes for a considerable distance. This can be
shown experimentally in animals by measuring a lengthshown experimentally in animals by measuring a length
of an artery in situ, and then removing it, when it mayof an artery in situ, and then removing it, when it may
shorten by as much as 40 per cent. If an artery is onlyshorten by as much as 40 per cent. If an artery is only
partly severed, the elastic tissue retracts from the edgespartly severed, the elastic tissue retracts from the edges
of the cut, which is thereby enlarged and keptof the cut, which is thereby enlarged and kept
open-‘button-holed’open-‘button-holed’

ANASTOMOSIS AND COLLATERAL CIRCULATIONANASTOMOSIS AND COLLATERAL CIRCULATION
 When an arterial trunk gives off successive branches, each of these throughWhen an arterial trunk gives off successive branches, each of these through
its numerous arterioles and capillaries supplies blood to a mass of tissueits numerous arterioles and capillaries supplies blood to a mass of tissue
which is termed its vascular area or territory. As a rule, the terminal capillarywhich is termed its vascular area or territory. As a rule, the terminal capillary
network of one artery communicates freely with that of an adjacent artery.network of one artery communicates freely with that of an adjacent artery.
Such a communication is anastomoses. If a main arterial trunkSuch a communication is anastomoses. If a main arterial trunk AA givesgives
origin to two lateral branches,origin to two lateral branches, BB andand CC, whose arterioles or capillaries, whose arterioles or capillaries
communicate freely with one another, then ifcommunicate freely with one another, then if AA is occluded at any pointis occluded at any point
between the origin of these two branches, some blood can still reach thebetween the origin of these two branches, some blood can still reach the
region beyond the obstruction via the anastomoses betweenregion beyond the obstruction via the anastomoses between BB and C. Theand C. The
flow of blood through the anastomoses is now termed a collateralflow of blood through the anastomoses is now termed a collateral
circulation. The amount of blood flowing through the anastomoses may atcirculation. The amount of blood flowing through the anastomoses may at
first be only small, but if it is enough to keep alive the tissue originallyfirst be only small, but if it is enough to keep alive the tissue originally
supplied bysupplied by AA, the collateral circulation will usually undergo progressive, the collateral circulation will usually undergo progressive
enlargement until finally it transmits as much blood as formerly wasenlargement until finally it transmits as much blood as formerly was
conveyed by the occluded vessel.conveyed by the occluded vessel.
 In the absence of any communication whatever betweenIn the absence of any communication whatever between BB andand C,C,
occlusion ofocclusion of AA wound result in the complete cessation of blood flow to itswound result in the complete cessation of blood flow to its
vascular territory, which would then die and become gangrenous. An arteryvascular territory, which would then die and become gangrenous. An artery
supplying a mass of tissue without any anastomoses with adjacent vascularsupplying a mass of tissue without any anastomoses with adjacent vascular
territories, or with anastomoses so poor as not to be able to maintain anterritories, or with anastomoses so poor as not to be able to maintain an
adequate supply of blood to the affected tissue if the artery is obstructed, isadequate supply of blood to the affected tissue if the artery is obstructed, is
an end-artery, in the former instance anatomical, in the latter functionalan end-artery, in the former instance anatomical, in the latter functional

GROWTH OF BLOOD VESSELSGROWTH OF BLOOD VESSELS
 General considerations:General considerations:
Blood vessels are capable of proliferation throughout life, though not so obviously in the adult asBlood vessels are capable of proliferation throughout life, though not so obviously in the adult as
in the embryo, or during childhood and adolescence, when body growth is proceeding actively. Inin the embryo, or during childhood and adolescence, when body growth is proceeding actively. In
the adult there is always a need, in some regions more than others, for the formation of newthe adult there is always a need, in some regions more than others, for the formation of new
capillaries to replace those damaged by normal wear and tear; but the process is more incapillaries to replace those damaged by normal wear and tear; but the process is more in
evidence in the tissue repair which follows the healing of wounds or of inflammation. A part fromevidence in the tissue repair which follows the healing of wounds or of inflammation. A part from
proliferation, capillaries may also enlarge and acquire a secondary coat, for example, when aproliferation, capillaries may also enlarge and acquire a secondary coat, for example, when a
collateral circulation expends from a capillary network to arteries of appreciable size. There iscollateral circulation expends from a capillary network to arteries of appreciable size. There is
also convincing evidence that additional arterio-venous anastomoses may readily develop,also convincing evidence that additional arterio-venous anastomoses may readily develop,
though in response to what stimulus this occurs is not known.though in response to what stimulus this occurs is not known.
 Growth in the adult :Growth in the adult :
Multiplication of vessels, as distinct from increase in size, occurs only in capillaries, by aMultiplication of vessels, as distinct from increase in size, occurs only in capillaries, by a
characteristic process of sprouting. Solid buds grow out of pre-existing capillaries, usually fromcharacteristic process of sprouting. Solid buds grow out of pre-existing capillaries, usually from
the summit of a loop ; and as the growing tip extends the elongating and perhaps branchingthe summit of a loop ; and as the growing tip extends the elongating and perhaps branching
vessel becomes hollow, and its lumen continuous with that of the parent and other vessels.vessel becomes hollow, and its lumen continuous with that of the parent and other vessels.
Adjacent capillary sprouts fuse with one another and give rise to a network. In the healing ofAdjacent capillary sprouts fuse with one another and give rise to a network. In the healing of
wounds the growth of capillaries is associated with the multiplication of per capillary fibroblasts,wounds the growth of capillaries is associated with the multiplication of per capillary fibroblasts,
whose activity results in the formation of collagen fibers and the appearance of scar tissue.whose activity results in the formation of collagen fibers and the appearance of scar tissue.
The process of capillary growth has been carefully observed, over long periods, in the ear of theThe process of capillary growth has been carefully observed, over long periods, in the ear of the
rabbit during life. Such observations show that regressive as well as growth changes can occur inrabbit during life. Such observations show that regressive as well as growth changes can occur in
capillaries, and that when they are not in active use for any length of time their lumen becomescapillaries, and that when they are not in active use for any length of time their lumen becomes
narrowed and obliterated; the solid cellular strand thus formed usually disappears.narrowed and obliterated; the solid cellular strand thus formed usually disappears.
Capillaries can enlarge and acquire a secondary coat, developing into arteries or veins accordingCapillaries can enlarge and acquire a secondary coat, developing into arteries or veins according
to the composition of this coat. It is this property of capillaries which is responsible for theto the composition of this coat. It is this property of capillaries which is responsible for the
formation of large blood vessels out of a capillary anastomoses, when a collateral circulation isformation of large blood vessels out of a capillary anastomoses, when a collateral circulation is
becoming established. New arteries and veins are always laid down in the first place asbecoming established. New arteries and veins are always laid down in the first place as
capillaries. It is not altogether clear from what tissue elements the secondary coat is derived,capillaries. It is not altogether clear from what tissue elements the secondary coat is derived,
when it forms around the primary endothelial tube; it is probable that the primitive adventitial cellswhen it forms around the primary endothelial tube; it is probable that the primitive adventitial cells
play in important part in the process.play in important part in the process.

EXAMINATION OF LIVING BLOOD VESSELS:EXAMINATION OF LIVING BLOOD VESSELS:
 Arteries:Arteries:
The pulsation of many arteries may be felt, and if they are near the surfaceThe pulsation of many arteries may be felt, and if they are near the surface
may also be seen. In the topographical section mention will be made ofmay also be seen. In the topographical section mention will be made of
some of the situations in which individual arteries may be identified. With asome of the situations in which individual arteries may be identified. With a
little care even small arteries may be detected, for example, the digitallittle care even small arteries may be detected, for example, the digital
arteries near the base of the finger, on either side of the proximal phalanx,arteries near the base of the finger, on either side of the proximal phalanx,
or the superficial palmer artery in front of the thenar eminence.or the superficial palmer artery in front of the thenar eminence.
 Capillaries:Capillaries:
The capillaries of the skin may be observed with the aid of a microscope, ifThe capillaries of the skin may be observed with the aid of a microscope, if
the epidermis is first cleared and rendered more or less transparent withthe epidermis is first cleared and rendered more or less transparent with
cedar-wood oil, and a strong beam of light focused on it. The mostcedar-wood oil, and a strong beam of light focused on it. The most
convenient situation for observing capillaries is the nail bed, where smallerconvenient situation for observing capillaries is the nail bed, where smaller
arterioles and venules can also occasionally be seen.arterioles and venules can also occasionally be seen.
 X-ray examination of blood vessels. [Angiography] :X-ray examination of blood vessels. [Angiography] :
In the thorax, simple X-ray examination is sufficient to demonstrate the heartIn the thorax, simple X-ray examination is sufficient to demonstrate the heart
and some of the larger blood vessels, for example, the arch of the aorta orand some of the larger blood vessels, for example, the arch of the aorta or
the branches of the pulmonary artery, as they radiate from the root of thethe branches of the pulmonary artery, as they radiate from the root of the
lung. These vascular shadows stand out because of the contrast affordedlung. These vascular shadows stand out because of the contrast afforded
by the air-containing lung tissue surrounding them. In other parts of theby the air-containing lung tissue surrounding them. In other parts of the
body, however, healthy blood vessels are not so readily visible onbody, however, healthy blood vessels are not so readily visible on
radiographic examination, and only become so it a radio-opaque substanceradiographic examination, and only become so it a radio-opaque substance
is injected into them; this procedure is known as angiography.is injected into them; this procedure is known as angiography.
Arteries of the body can be subdivided into those of pulmonary and those ofArteries of the body can be subdivided into those of pulmonary and those of
systemic circulation.systemic circulation.

ARCH OF AORTA AND its BRANCHESARCH OF AORTA AND its BRANCHES
 It extends mainly in the anterioposterior direction but also inclines to the left.It extends mainly in the anterioposterior direction but also inclines to the left.
At first it is in the front of the superior mediastinum, but it then passes backAt first it is in the front of the superior mediastinum, but it then passes back
to the back of superior mediastinum reaches the left side of the body of 4thto the back of superior mediastinum reaches the left side of the body of 4th
thoracic vertebra, where it continues as descending thoracic aorta.thoracic vertebra, where it continues as descending thoracic aorta.
 From before backwards the aortic arch gives origin to the brachiocephalic,From before backwards the aortic arch gives origin to the brachiocephalic,
left common carotid and left common carotid and left subclavian arteries.left common carotid and left common carotid and left subclavian arteries.
 The left brachiocephalic vein and thymus gland lie anterior to the commonThe left brachiocephalic vein and thymus gland lie anterior to the common
cement of these 3 arteries and to the summit of the aortic arch.cement of these 3 arteries and to the summit of the aortic arch.
 The arch of aorta and its branches not frequently provide excellentThe arch of aorta and its branches not frequently provide excellent
examples of arterial variations. For ex: the arch of the aorta is normallyexamples of arterial variations. For ex: the arch of the aorta is normally
developed from the 4th. Left brachial artery, but it may occasionally developdeveloped from the 4th. Left brachial artery, but it may occasionally develop
form the fourth right, as normally happens in birds, in which cases the archform the fourth right, as normally happens in birds, in which cases the arch
passes to the right of the vertebral column.passes to the right of the vertebral column.
 Variation in branches :Variation in branches :
While minor variation in the origin of the vessels arising from the aortic archWhile minor variation in the origin of the vessels arising from the aortic arch
are relatively common, they are also of little surgical importance.are relatively common, they are also of little surgical importance.
With the exception of right andWith the exception of right and double aortic arch and anomalies ofdouble aortic arch and anomalies of
subclavian arteries..subclavian arteries..

BRACHIOCEPHALIC ARTERYBRACHIOCEPHALIC ARTERY
 COURSE AND SURFACE ANATOMY :COURSE AND SURFACE ANATOMY :
 The brachiocephalic trunk arises from the arch of aorta behind theThe brachiocephalic trunk arises from the arch of aorta behind the
middle of manubrium sterni. It is 3.5 to 5 cm long and runsmiddle of manubrium sterni. It is 3.5 to 5 cm long and runs
upwards, backward and to the right from the superior mediastinumupwards, backward and to the right from the superior mediastinum
into the root of the neck. It ends at the level of the upper part of Rtinto the root of the neck. It ends at the level of the upper part of Rt
sternoclavicular joint by dividing into right subclavian and commonsternoclavicular joint by dividing into right subclavian and common
carotid arteries.carotid arteries.
 Anteriorly the left brachiocephalic vein crosses between it andAnteriorly the left brachiocephalic vein crosses between it and
thymus.thymus.
 At higher levels the sternothyroid muscle separates it fromAt higher levels the sternothyroid muscle separates it from
sternohyoid and sternoclavicular joint. On its left side left commonsternohyoid and sternoclavicular joint. On its left side left common
carotid artery originates and at a higher level trachea is in contactcarotid artery originates and at a higher level trachea is in contact
with it.with it.
 Branches:Branches:
As well as its two terminal branches the brachiocephalic trunk mayAs well as its two terminal branches the brachiocephalic trunk may
give off the thyroidea Ima which runs on the front of trachea to thegive off the thyroidea Ima which runs on the front of trachea to the
thyroidthyroid

COMMON CAROTID ARTERIESCOMMON CAROTID ARTERIES
 SURFACE ANATOMY:SURFACE ANATOMY:
 A line from a point just below andA line from a point just below and
to the left of the centre ofto the left of the centre of
manubrium sterni to themanubrium sterni to the
sternoclavicular joint – representssternoclavicular joint – represents
thoracic portion.thoracic portion.
 The cervical portion of the leftThe cervical portion of the left
artery and all of the right isartery and all of the right is
indicated by a line drawn from theindicated by a line drawn from the
appropriate sternoclavicular jointappropriate sternoclavicular joint
to a point 1 cm behind the superiorto a point 1 cm behind the superior
horn of thyroid cartilage.horn of thyroid cartilage.
 The left common carotid artery isThe left common carotid artery is
intermediate in position among theintermediate in position among the
three branches of the arch ofthree branches of the arch of
aorta. It ascends upwards behindaorta. It ascends upwards behind
the manubrium sterni to the levelthe manubrium sterni to the level
of the left sternoclavicularof the left sternoclavicular
articulation from where it isarticulation from where it is
continued to the neck. Thus thecontinued to the neck. Thus the
left subclavian artery can beleft subclavian artery can be
divided into thoraic and cervicaldivided into thoraic and cervical
part.part.

 Thoraic part:Thoraic part:
 Course and relationCourse and relation
 Anteriorly – related to back of manubrium sterni being separated byAnteriorly – related to back of manubrium sterni being separated by
sternohyoid and sternothyroid muscles.sternohyoid and sternothyroid muscles.
 Close to its origin it is crossed in front by the left branchiocephalicClose to its origin it is crossed in front by the left branchiocephalic
(innominate) vein.(innominate) vein.
 Posteriorly: It is related to trachea, left edge of oesophagus, thoraicPosteriorly: It is related to trachea, left edge of oesophagus, thoraic
duct and the left recurrent laryngerial nerve.duct and the left recurrent laryngerial nerve.
 On right side – Related to brachiocephalic (innominate) artery inOn right side – Related to brachiocephalic (innominate) artery in
lower part and trachea in its upper part.lower part and trachea in its upper part.
 On left side – It is related to phremic nerve. The left subclavianOn left side – It is related to phremic nerve. The left subclavian
artery the left lung and the pleura.artery the left lung and the pleura.
 It does not provide any branch in the thorax.It does not provide any branch in the thorax.

 CERVICAL PART :CERVICAL PART :
The common carotid artery enters the neck behind the sternoclavicular articulationThe common carotid artery enters the neck behind the sternoclavicular articulation
and ascends upwards and backwards under the cover of anterior margin.and ascends upwards and backwards under the cover of anterior margin.
sternomastoid up to the upper border of thyroid cartilage.sternomastoid up to the upper border of thyroid cartilage.
 Relations :Relations :
Posteriorly – related to anterior tubercles of the transverse processes of the lower,Posteriorly – related to anterior tubercles of the transverse processes of the lower,
four cervical vertebrae and the origins of the scalenus anterior and longus cervicisfour cervical vertebrae and the origins of the scalenus anterior and longus cervicis
and capitis muscle. At the root of the neck it is related posteriorly to the 1st portion ofand capitis muscle. At the root of the neck it is related posteriorly to the 1st portion of
vertebral artery and the origin of inferior thyroid artery.vertebral artery and the origin of inferior thyroid artery.
 Anteriorly :Anteriorly :
Covered by skin superfacial fascia, platsyma and the deep fascia is overlapped, byCovered by skin superfacial fascia, platsyma and the deep fascia is overlapped, by
the anterior margin of sternomastoid muscle. In the lower part of the neck the inferiorthe anterior margin of sternomastoid muscle. In the lower part of the neck the inferior
belly of omohyoid sternothyroid and sternohyoid intervene between it.belly of omohyoid sternothyroid and sternohyoid intervene between it.
 Laterally :Laterally :
It is covered by sternomastoid being separated by carotid sheath.It is covered by sternomastoid being separated by carotid sheath.
 Medially :Medially :
It is related to the pharynx larynx, trachea oesophagus and the thyroid gland.It is related to the pharynx larynx, trachea oesophagus and the thyroid gland.
 Except its terminal branches (external and internal carotid arteries) usually it does notExcept its terminal branches (external and internal carotid arteries) usually it does not
provide any branches in the neck.provide any branches in the neck.
 It it’s point of bifurcation it usually represents a dilation known as “carotid sinus”. ThisIt it’s point of bifurcation it usually represents a dilation known as “carotid sinus”. This
is due to thickness of tunica media with proportionate thickness of the tumicais due to thickness of tunica media with proportionate thickness of the tumica
adventia. The carotid sinus is richly supplied with sympathetic and parasympatheticadventia. The carotid sinus is richly supplied with sympathetic and parasympathetic
(glossophrengal) nerves and is concerned in regulation of blood pressure in the(glossophrengal) nerves and is concerned in regulation of blood pressure in the
cerebral arteriescerebral arteries

 DEVELOPMENT :DEVELOPMENT :
The third aortic arch together with theThe third aortic arch together with the
persisting dorsal aorta cranial to it forms thepersisting dorsal aorta cranial to it forms the
common and internal carotid arteries.common and internal carotid arteries.
 ANOMALIES :ANOMALIES :
When the innominate stem is absorbed intoWhen the innominate stem is absorbed into
the aortic arch the right common carotidthe aortic arch the right common carotid
artery arises from the arch of aorta andartery arises from the arch of aorta and
forms the second branch from the right sideforms the second branch from the right side
(1st being RT subclavian).(1st being RT subclavian).
When the right 4th aortic arch is obliteratedWhen the right 4th aortic arch is obliterated
the right subclavian arises from thethe right subclavian arises from the
descending aorta, and the right commondescending aorta, and the right common
carotid in this case forms the 1st branch ofcarotid in this case forms the 1st branch of
the arch of aorta.the arch of aorta.
The common carotid may fail to divide or itThe common carotid may fail to divide or it
may divide either at a higher or at a lowermay divide either at a higher or at a lower
level. When it odes not divide the brancheslevel. When it odes not divide the branches
which usually arise from the external carotidwhich usually arise from the external carotid
will arise from itwill arise from it

APPLIED SURGICAL ANATOMY (CLINICAL RELIVANCE)APPLIED SURGICAL ANATOMY (CLINICAL RELIVANCE)
 CAROTID ENDARTERECTOMY:CAROTID ENDARTERECTOMY:
Atheroscleraotic thickening of the intima of internal carotid artery, which obstructs blood flow canAtheroscleraotic thickening of the intima of internal carotid artery, which obstructs blood flow can
be observed in Doppler color study.be observed in Doppler color study.
A Doppler in a diagnostic instrument that emits an ultrasonic beam that reflects from movingA Doppler in a diagnostic instrument that emits an ultrasonic beam that reflects from moving
structure partial occlusion of the internal carotid may also cause a transient ischemic attack –structure partial occlusion of the internal carotid may also cause a transient ischemic attack –
sudden focal loss of neurological function. (ex: dizziness and disorientation). That appear withinsudden focal loss of neurological function. (ex: dizziness and disorientation). That appear within
24 hours. Arterial occlusion may also cause a minor stroke – loss of neurological function such24 hours. Arterial occlusion may also cause a minor stroke – loss of neurological function such
as weakness or sensory loss on one side of the body that exceeds 24 hour but disappear within 3as weakness or sensory loss on one side of the body that exceeds 24 hour but disappear within 3
weeks. They symptoms resulting from obstruction of blood flow depend on the degree ofweeks. They symptoms resulting from obstruction of blood flow depend on the degree of
obstruction and the amount of collateral blood flow to the brain and structures in the orbit fromobstruction and the amount of collateral blood flow to the brain and structures in the orbit from
other arteries.other arteries.
Carotid stenosis (narrowing) in healthy patients can be relieved by opening the artery andCarotid stenosis (narrowing) in healthy patients can be relieved by opening the artery and
stripping off the atherosclerofic plaque with the intima. The common site of carotid,stripping off the atherosclerofic plaque with the intima. The common site of carotid,
endarterectomy is the internal carotid artery. Just superior to the origin after the operationendarterectomy is the internal carotid artery. Just superior to the origin after the operation
administered drug inhibit clot formation in the operated area until the endothelium has re grown.administered drug inhibit clot formation in the operated area until the endothelium has re grown.
 CAROTID PULSE:CAROTID PULSE:
The carotid pulse (neck) is easily felt by palpating the common carotid artery in the side of theThe carotid pulse (neck) is easily felt by palpating the common carotid artery in the side of the
neck. Where it lies in the groove between trachea and infrahyoid muscle. It is usually easilyneck. Where it lies in the groove between trachea and infrahyoid muscle. It is usually easily
palpated just deep to the anterior border of sternocledomastoid muscle, at the level of superiorpalpated just deep to the anterior border of sternocledomastoid muscle, at the level of superior
border of thyroid cartilage. It is routinely checked during CARDIOPULMONARYborder of thyroid cartilage. It is routinely checked during CARDIOPULMONARY
RESUSCITATION. Absence of carotid pulse indicates ceratoid arrest.RESUSCITATION. Absence of carotid pulse indicates ceratoid arrest.
 CAROTID ARTERY PALPATION :CAROTID ARTERY PALPATION :
External pressure on the carotid artery in people with carotid sinus hypersensitivity may cause.External pressure on the carotid artery in people with carotid sinus hypersensitivity may cause.
Slowing of heart rate, fall in blood pressure and cardiac ischemia with fainting.Slowing of heart rate, fall in blood pressure and cardiac ischemia with fainting.
In al forms of syncope symptoms result from sudden and critical decrease in cerebral perfusion.In al forms of syncope symptoms result from sudden and critical decrease in cerebral perfusion.
Consequently this method of taking the pulse in not recommended for cardiac patients who areConsequently this method of taking the pulse in not recommended for cardiac patients who are
participating in cardiac rehabilitation programs. Because various types of vascular disease affectparticipating in cardiac rehabilitation programs. Because various types of vascular disease affect
the sensitivity of the carotid sinus, the radial pulse at the resist is most commonly checked.the sensitivity of the carotid sinus, the radial pulse at the resist is most commonly checked.

THE EXTERNAL CAROTID ARTERYTHE EXTERNAL CAROTID ARTERY
 Branches of the external carotid artery :Branches of the external carotid artery :
1.1. Superior thyroidSuperior thyroid
2.2. Ascending pharyngealAscending pharyngeal
3.3. LingualLingual
4.4. FacialFacial
5.5. OccipitalOccipital
6.6. Posterior auricularPosterior auricular
7.7. Superficial temporalSuperficial temporal
8.8. Maxillary.Maxillary.
 DevelopmentDevelopment : The external carotid artery arises as a branch: The external carotid artery arises as a branch
budding off from the ventral root of the third aortic arch.budding off from the ventral root of the third aortic arch.
 Anomalies :Anomalies : As already stated there may be complete absence ofAs already stated there may be complete absence of
the external carotid artery or occasionally it may arise directly fromthe external carotid artery or occasionally it may arise directly from
the arch of the aorta.the arch of the aorta.

Superior thyroid arterySuperior thyroid artery ::
 It arises from the front of the external carotid artery immediatelyIt arises from the front of the external carotid artery immediately
below the greater cornu of the hyoid bone. At first it lies under coverbelow the greater cornu of the hyoid bone. At first it lies under cover
of the anterior border of the sternocleidomastoid muscle and then itof the anterior border of the sternocleidomastoid muscle and then it
becomes superficial being covered only by the skin, superficialbecomes superficial being covered only by the skin, superficial
fascia, platysma and the deep fascia and then again it becomesfascia, platysma and the deep fascia and then again it becomes
deep as it descends downwards beneath the omohyoid (superiordeep as it descends downwards beneath the omohyoid (superior
belly), sternohyoid and sternothyroid muscles and finally reachingbelly), sternohyoid and sternothyroid muscles and finally reaching
the upper pole of the thyroid gland it breaks up into the terminalthe upper pole of the thyroid gland it breaks up into the terminal
branches anterior and posterior. Medially it is related to the inferiorbranches anterior and posterior. Medially it is related to the inferior
constrictor muscle of the pharynx and the external laryngeal nerve.constrictor muscle of the pharynx and the external laryngeal nerve.
 The anterior branch runs along the medial border of the upperThe anterior branch runs along the medial border of the upper
poly of the thyroid gland and supplies the superficial surface of thepoly of the thyroid gland and supplies the superficial surface of the
thyroid and provides an anastomosing branch which runs along andthyroid and provides an anastomosing branch which runs along and
upper border of the isthmus and end by anastomosing with theupper border of the isthmus and end by anastomosing with the
fellow of the opposite side.fellow of the opposite side.
 The posterior branch runs along the posterior border of theThe posterior branch runs along the posterior border of the
gland and supplies the medial and the posterior surfaces and finallygland and supplies the medial and the posterior surfaces and finally
ends by anastomosing with the inferior thyroid artery.ends by anastomosing with the inferior thyroid artery.

 Branches :Branches :
1.1. InfrahyoidInfrahyoid
2.2. SternomastoidSternomastoid
3.3. Superior laryngealSuperior laryngeal
4.4. CricothyroidCricothyroid
5.5. Terminal glandularTerminal glandular

 Infrahyoid branch :Infrahyoid branch : This is a small branch arising from the superiorThis is a small branch arising from the superior
thyroid artery and runs forwards along the lower border of the hyoidthyroid artery and runs forwards along the lower border of the hyoid
bone and ends by anastomosing with the fellow of its opposite side.bone and ends by anastomosing with the fellow of its opposite side.
 Sternomastoid branch :Sternomastoid branch : The sternomastoid branch of the superiorThe sternomastoid branch of the superior
thyroid artier runs downwards and laterally in front of the carotidthyroid artier runs downwards and laterally in front of the carotid
sheath and soon enters into the sternomastoid muscle. This arterysheath and soon enters into the sternomastoid muscle. This artery
may arise from the external carotid artery.may arise from the external carotid artery.
 Superior laryngeal branch :Superior laryngeal branch : The superior laryngeal branch of theThe superior laryngeal branch of the
superior thyroid artery is larger than the preceding two arteries andsuperior thyroid artery is larger than the preceding two arteries and
runs upwards and medially behind thyrohyoid muscle andruns upwards and medially behind thyrohyoid muscle and
accompanying the internal laryngeal nerve it pierces the hyothyroidaccompanying the internal laryngeal nerve it pierces the hyothyroid
membrane and lies below the internal laryngeal nerve. It suppliesmembrane and lies below the internal laryngeal nerve. It supplies
the muscles, mucous membranes and glands of the larynx and endsthe muscles, mucous membranes and glands of the larynx and ends
by anastomosing with the fellow of its opposite side and also withby anastomosing with the fellow of its opposite side and also with
the inferior laryngeal branch of the inferior thyroid artery.the inferior laryngeal branch of the inferior thyroid artery.
 Cricothyroid branch :Cricothyroid branch : It is a transverse branch from the superiorIt is a transverse branch from the superior
thyroid artery and runs transversely across the upper border of thethyroid artery and runs transversely across the upper border of the
cricothyroid membrane and ends by anastomosing with the artery ofcricothyroid membrane and ends by anastomosing with the artery of
the opposite sidethe opposite side
 Terminal glandular branch :Terminal glandular branch : The terminal glandular branches areThe terminal glandular branches are
anterior and posterior and have been described with the main arteryanterior and posterior and have been described with the main artery

Lingual arteryLingual artery ::
 First part of the lingual artery :First part of the lingual artery : The firstThe first
part of lingual artery lies in the carotidpart of lingual artery lies in the carotid
triangle and extends from its origin to thetriangle and extends from its origin to the
posterior border of the hyoglossus muscle;posterior border of the hyoglossus muscle;
at first it runs upwards, forwards andat first it runs upwards, forwards and
medially and then forming a loop descendsmedially and then forming a loop descends
downwards to the greater cornu of the hyoiddownwards to the greater cornu of the hyoid
bone and reaches the posterior border ofbone and reaches the posterior border of
the hyoglossus muscle; in this part of itsthe hyoglossus muscle; in this part of its
course it is superficial, being covered onlycourse it is superficial, being covered only
by the skin, superficial fascia, platysma andby the skin, superficial fascia, platysma and
the deep fascia; it lies on the middlethe deep fascia; it lies on the middle
constrictor muscle of the pharynx. The loopconstrictor muscle of the pharynx. The loop
which is the characteristic of the artery iswhich is the characteristic of the artery is
crosses by the hypoglossal nerve.crosses by the hypoglossal nerve.
 Second part of the lingual artery :Second part of the lingual artery : TheThe
second part of the lingual artery lies deep tosecond part of the lingual artery lies deep to
the hyoglossus muscle. In this part of itsthe hyoglossus muscle. In this part of its
course it runs along the upper border of thecourse it runs along the upper border of the
hyoid bone and is covered by thehyoid bone and is covered by the
hyoglossus muscle, the tendon of thehyoglossus muscle, the tendon of the
digastric, stylohyoid and the posterior part ofdigastric, stylohyoid and the posterior part of
the mylohyoid muscle and the lower part ofthe mylohyoid muscle and the lower part of
the submandibular gland. It is separatedthe submandibular gland. It is separated
from the hypoglossal nerve and its venaefrom the hypoglossal nerve and its venae
commitans by the hyoglossus muscle. It liescommitans by the hyoglossus muscle. It lies
on the middle constrictor muscle of theon the middle constrictor muscle of the
pharynx.pharynx.

Lingual arteryLingual artery :: 33rdrd
part of the lingual artery :part of the lingual artery :
 The third part of the lingual arteryThe third part of the lingual artery
extends from the anterior border of theextends from the anterior border of the
hyoglossus muscle to the tip of thehyoglossus muscle to the tip of the
tongue. At the anterior border of thetongue. At the anterior border of the
hyoglossus muscle the lingual arteryhyoglossus muscle the lingual artery
gives out its sublingual branch andgives out its sublingual branch and
then is continued to the under surfacethen is continued to the under surface
of the tongue as the arteria profundaof the tongue as the arteria profunda
linguae. At first it ascends verticallylinguae. At first it ascends vertically
upwards and then runs forwardsupwards and then runs forwards
vertically upwards and then runsvertically upwards and then runs
forwards to the under surface of theforwards to the under surface of the
tongue on the side of the frenulum andtongue on the side of the frenulum and
finally reaches the tip of the tonguefinally reaches the tip of the tongue
where it ends by anastomosing withwhere it ends by anastomosing with
the fellow of its opposite side. In thisthe fellow of its opposite side. In this
part of its course it is accompanied bypart of its course it is accompanied by
the lingual nerve, and thethe lingual nerve, and the
genioglossus muscles lies on itsgenioglossus muscles lies on its
medial side. Latterly it is related to themedial side. Latterly it is related to the
lingitudinalis linguae inferior andlingitudinalis linguae inferior and
inferiorly is covered only by theinferiorly is covered only by the
mucous membrane of the tongue.mucous membrane of the tongue.
 SuprayhoidSuprayhoid
 Rami dorsales linguaeRami dorsales linguae
 SublingualSublingual
 Arteria profunda linguae.Arteria profunda linguae.

FACIAL ARTERYFACIAL ARTERY
 CERVICAL PART OF THE FACIAL ARTERY :CERVICAL PART OF THE FACIAL ARTERY :
 Course :Course : In the neck, the facial artery arises fromIn the neck, the facial artery arises from
the anterior aspect of the external carotid artery inthe anterior aspect of the external carotid artery in
the carotid triangle a little higher than the lingualthe carotid triangle a little higher than the lingual
artery and immediately above the greater cornu ofartery and immediately above the greater cornu of
the hyoid bone. From its origin it ascends verticallythe hyoid bone. From its origin it ascends vertically
upwards to the angle of the mandible and thenupwards to the angle of the mandible and then
turns downwards forming a loop and descends inturns downwards forming a loop and descends in
the groove on the posterior part of thethe groove on the posterior part of the
submandibular gland and then it passes forwardssubmandibular gland and then it passes forwards
between the lateral surface of the submandibularbetween the lateral surface of the submandibular
gland and the medial pterygoid muscle and reachgland and the medial pterygoid muscle and reach
the lower border of the mandible and finally itthe lower border of the mandible and finally it
arches over the mandible to enter the face at thearches over the mandible to enter the face at the
anterior border of the masseter muscle.anterior border of the masseter muscle.
 Relation :Relation : In is course through the neck it is at firstIn is course through the neck it is at first
superficial being covered only by the skin,superficial being covered only by the skin,
superficial fascia, platysma and the deep fascia,superficial fascia, platysma and the deep fascia,
and opposite the angle of the mandible it becomesand opposite the angle of the mandible it becomes
deep by passing beneath the posterior belly of thedeep by passing beneath the posterior belly of the
digastric and the stylohyoid muscles. Then it lies indigastric and the stylohyoid muscles. Then it lies in
the groove on the posterior aspect of thethe groove on the posterior aspect of the
submandibularsubmandibular gland, and subsequently, it liesgland, and subsequently, it lies
between the gland and the medial pterygoidbetween the gland and the medial pterygoid
muscle. Again it mandible to enter into the face.muscle. Again it mandible to enter into the face.
Here the (anterior) facial vein lies posterior to it. AtHere the (anterior) facial vein lies posterior to it. At
first it lies on the middle constrictor muscle of thefirst it lies on the middle constrictor muscle of the
pharynx, and higher up, opposite the angle of thepharynx, and higher up, opposite the angle of the
mandible lies on the superior constrictor muscle ormandible lies on the superior constrictor muscle or
it may ascent further up to lie on the styloglossusit may ascent further up to lie on the styloglossus
muscle and in this situation it is separated from themuscle and in this situation it is separated from the
palatine tonsil by the superior constrictor and thepalatine tonsil by the superior constrictor and the
styloglossus muscles. Occasionally it may bestyloglossus muscles. Occasionally it may be
crossed by the hypoglossal nerve.crossed by the hypoglossal nerve.

 FACIAL PART OF THE FACIAL ARTERY :FACIAL PART OF THE FACIAL ARTERY :
 Course :Course : The facial artery enters the face atThe facial artery enters the face at
the anterior border of the masseter musclethe anterior border of the masseter muscle
and ascends upwards and forwards acrossand ascends upwards and forwards across
the cheek to reach the angle of the mouththe cheek to reach the angle of the mouth
and then ascends further up along the sideand then ascends further up along the side
of the nose to reach the medial palpebralof the nose to reach the medial palpebral
commissure where it ends by anastomosingcommissure where it ends by anastomosing
with the dorsal nasal branch of thewith the dorsal nasal branch of the
ophthalmic artery.ophthalmic artery.
 Relation :Relation : Opposite the anterior border ofOpposite the anterior border of
the masseter it is superficial and lies underthe masseter it is superficial and lies under
cover of the skin, superficial fascia and thecover of the skin, superficial fascia and the
platysma. In its course through the face it isplatysma. In its course through the face it is
covered by the skin, fat of the cheek, andcovered by the skin, fat of the cheek, and
opposite the angle of the mouth, it liesopposite the angle of the mouth, it lies
under the risorius and the zygomaticusunder the risorius and the zygomaticus
major ; opposite the medial palpebralmajor ; opposite the medial palpebral
commissure it is hidden by the fibres of thecommissure it is hidden by the fibres of the
levator labii superioris alaeque nasi. It lieslevator labii superioris alaeque nasi. It lies
successively upon anguli oris and thesuccessively upon anguli oris and the
levator labii superioris alaeque nasi. Thelevator labii superioris alaeque nasi. The
(anterior) facial vein lies posterior to it(anterior) facial vein lies posterior to it
opposite the medial palpebral commissureopposite the medial palpebral commissure
and then is separated from it by aand then is separated from it by a
considerable distance and opposite theconsiderable distance and opposite the
anterior border of the masseter, it againanterior border of the masseter, it again
comes into intimate relation with the arterycomes into intimate relation with the artery
and lies immediately posterior to it.and lies immediately posterior to it.

 Cervical part :Cervical part :
 Ascending palatineAscending palatine
 TonsillarTonsillar
 GlandularGlandular
 SubmentalSubmental
 Facial part :Facial part :
 Superior labialSuperior labial
 Inferior labialInferior labial
 Lateral nasal.Lateral nasal.

Occipital arteryOccipital artery ::
 Course :Course : The occipital artery arises fromThe occipital artery arises from
the external carotid artery opposite thethe external carotid artery opposite the
origin of the facial artery. It ascendsorigin of the facial artery. It ascends
upwards and backwards to reach theupwards and backwards to reach the
posterior part of the scalp where it ends byposterior part of the scalp where it ends by
supplying it.supplying it.
 Relation :Relation : At first it lies in the carotid onlyAt first it lies in the carotid only
by the skin, superficial fascia, platysma andby the skin, superficial fascia, platysma and
deep fascia. Then as it runs upwards anddeep fascia. Then as it runs upwards and
backwards it crosses the internal carotidbackwards it crosses the internal carotid
artery, the internal jugular vein, theartery, the internal jugular vein, the
hypoglossal (which hooks round it), thehypoglossal (which hooks round it), the
vagus and the accessory nerves and thenvagus and the accessory nerves and then
passes under cover of the posterior belly ofpasses under cover of the posterior belly of
the digastric to reach the posterior betweenthe digastric to reach the posterior between
the transverse process of the atlas and thethe transverse process of the atlas and the
mastoid process of the temporal bone. Thenmastoid process of the temporal bone. Then
it traverses the groove on the mastoid partit traverses the groove on the mastoid part
of the temporal plenius capitis, longissimusof the temporal plenius capitis, longissimus
capitis and the posterior belly of thecapitis and the posterior belly of the
digastric. Finally it aponeurotic connectiondigastric. Finally it aponeurotic connection
between the sternomastoid and thebetween the sternomastoid and the
trapezius and then divides into branchestrapezius and then divides into branches
which pass in the subcutaneous tissue ofwhich pass in the subcutaneous tissue of
the scalp and ends by supplying it. In thethe scalp and ends by supplying it. In the
course upwards and backwards from abovecourse upwards and backwards from above
the level of the transverse process of thethe level of the transverse process of the
atlas to the scalp it lies successively uponatlas to the scalp it lies successively upon
the rectus captitis lateralis, obliquus capitisthe rectus captitis lateralis, obliquus capitis
superior and the semispinalis capitis. Itssuperior and the semispinalis capitis. Its
terminal branches are accompanied by heterminal branches are accompanied by he
branches from the greater occipital nerve.branches from the greater occipital nerve.

Occipital artery :Occipital artery :
 SternomastoidSternomastoid
 MastoidMastoid
 AuricularAuricular
 MuscularMuscular
 DescendingDescending
 MeningealMeningeal
 Occipital (terminal branchesOccipital (terminal branches

Ascending pharyngeal artery :Ascending pharyngeal artery :
 This is the smallestThis is the smallest
branch from the externalbranch from the external
carotid artery and arisescarotid artery and arises
from it just after it origin.from it just after it origin.
It is deeply seated andIt is deeply seated and
runs vertically upwardsruns vertically upwards
on the longus capitison the longus capitis
muscle to the base of themuscle to the base of the
skull and lies in betweenskull and lies in between
the internal carotid arterythe internal carotid artery
and the side wall of theand the side wall of the
pharynx. It is crossed bypharynx. It is crossed by
the styloglossus and thethe styloglossus and the
stylopharygneus. At thestylopharygneus. At the
base of the skull itbase of the skull it
anastomoses with theanastomoses with the
ascending palatineascending palatine
branch of the facialbranch of the facial
artery.artery.

Ascending pharyngeal arteryAscending pharyngeal artery
 PharyngealPharyngeal
 Inferior tympanicInferior tympanic
 MeningealMeningeal
 Pharyngeal branches :Pharyngeal branches : The pharyngeal branches of the ascendingThe pharyngeal branches of the ascending
pharyngeal artery are two or three in number and they supply the muscles ofpharyngeal artery are two or three in number and they supply the muscles of
the pharynx. One of the branches passes through the gap between thethe pharynx. One of the branches passes through the gap between the
upper border of the superior constrictor muscle of the pharynx and the baseupper border of the superior constrictor muscle of the pharynx and the base
of the skull and accompanying the levator muscle it enters the soft palate. Itof the skull and accompanying the levator muscle it enters the soft palate. It
may replace the ascending palatine branch of the facial artery.may replace the ascending palatine branch of the facial artery.
 Inferior tympanic branch :Inferior tympanic branch : It is a small branch which enters the tympanicIt is a small branch which enters the tympanic
cavity through the tympanic canaliculus in company with the tympaniccavity through the tympanic canaliculus in company with the tympanic
branch of the glossopharyngeal nerve. It supplies the medial wall of thebranch of the glossopharyngeal nerve. It supplies the medial wall of the
tympanic cavity and ends by anastomosing with the other tympanic arteries.tympanic cavity and ends by anastomosing with the other tympanic arteries.
 Meningeal branches :Meningeal branches : They are several small branches which supply theThey are several small branches which supply the
dura mater. They enter the cranial cavity through the anterior condylardura mater. They enter the cranial cavity through the anterior condylar
canal, jugular foramen and foramen lacerum.canal, jugular foramen and foramen lacerum.

Posterior auricular artery :Posterior auricular artery :
 It is small branch from theIt is small branch from the
external carotid arteryexternal carotid artery
and arsis from it as it isand arsis from it as it is
crossed by the posteriorcrossed by the posterior
belly of the digastric andbelly of the digastric and
the stylohyoid muscles. Itthe stylohyoid muscles. It
runs upwards andruns upwards and
backwards under cover ofbackwards under cover of
the parotid gland to reachthe parotid gland to reach
the mastoid processthe mastoid process
where it ends by dividingwhere it ends by dividing
into auricular andinto auricular and
occipital branches.occipital branches.

Posterior auricular artery :Posterior auricular artery :
 BranchesBranches
 OccipitalOccipital
 StylomastoidStylomastoid
 Auricular branch :Auricular branch : It supplies the posterior part of the auricle andIt supplies the posterior part of the auricle and
ends by anastomosing with posterior and auricular branches of theends by anastomosing with posterior and auricular branches of the
superficial temporal artery.superficial temporal artery.
 Occipital branch :Occipital branch : It passes laterally crossing the mastoid processIt passes laterally crossing the mastoid process
and reaches the posterior part of the scalp where it ends byand reaches the posterior part of the scalp where it ends by
anastomosing with the occipital artery.anastomosing with the occipital artery.
 Stylomastoid branch :Stylomastoid branch : The stylomastoid branch of the posteriorThe stylomastoid branch of the posterior
auricular artery enters the stylomastoid foramen and then entersauricular artery enters the stylomastoid foramen and then enters
into the tympanic cavity. It supplies the tympanic cavity, theinto the tympanic cavity. It supplies the tympanic cavity, the
tympanic antrum, the mastoid air cells and the semicircular canalstympanic antrum, the mastoid air cells and the semicircular canals
and anastomoses with the superficial petrosal branch of the middleand anastomoses with the superficial petrosal branch of the middle
meningeal arterymeningeal artery

Superficial temporal arterySuperficial temporal artery
 It is the smaller terminal branch ofIt is the smaller terminal branch of
the external carotid artery andthe external carotid artery and
arises from the same opposite thearises from the same opposite the
neck of the mandible within theneck of the mandible within the
substance of the parotid gland. Itsubstance of the parotid gland. It
then crosses the posterior root ofthen crosses the posterior root of
the zygomatic process andthe zygomatic process and
ascends vertically upwards underascends vertically upwards under
cover of the auricularis anterior forcover of the auricularis anterior for
about 5.0 cm and ends by dividingabout 5.0 cm and ends by dividing
into the anterior and posteriorinto the anterior and posterior
branches. Within the parotid glandbranches. Within the parotid gland
it is crossed by the zygomatic andit is crossed by the zygomatic and
the temporal branches of the facialthe temporal branches of the facial
nerve. Outside the parotid glandnerve. Outside the parotid gland
the auriculotemporal nerve liesthe auriculotemporal nerve lies
posterior to it and the temporalposterior to it and the temporal
branch of the facial nerve liesbranch of the facial nerve lies
anterior to it. It gives out theanterior to it. It gives out the
following branches:following branches:

Superficial temporal arterySuperficial temporal artery
 Transverse facialTransverse facial
 Zygomatico-orbitalZygomatico-orbital
 Middle temporalMiddle temporal
 FrontalFrontal
 Parietal.Parietal.
 Transverse facial branch :Transverse facial branch : It arises from it from within the parotid gland and crossesIt arises from it from within the parotid gland and crosses
superficial to the masseter muscle lying above the parotid duct and supplies thesuperficial to the masseter muscle lying above the parotid duct and supplies the
parotid gland with its ducts, the masseter muscle and the adjacent skin. Itparotid gland with its ducts, the masseter muscle and the adjacent skin. It
anastomoses with facial infra-orbital, buccal and masseteric arteries.anastomoses with facial infra-orbital, buccal and masseteric arteries.
 Auricular branches :Auricular branches : They are distributed to the lobule, the anterior part of theThey are distributed to the lobule, the anterior part of the
auricle and external auditory meatus and anastomoses with the posterior auricularauricle and external auditory meatus and anastomoses with the posterior auricular
artery.artery.
 Zygomatico-orbital branch :Zygomatico-orbital branch : It runs along the upper border of the zygomatic archIt runs along the upper border of the zygomatic arch
between the two layers of the temporal fascia to the lateral angle of the orbit where itbetween the two layers of the temporal fascia to the lateral angle of the orbit where it
anastomoses with the lacrimal and palpebral branches of the ophthalmic artery.anastomoses with the lacrimal and palpebral branches of the ophthalmic artery.
 Middle temporal branch :Middle temporal branch : It arises from the superficial temporal artery above theIt arises from the superficial temporal artery above the
zygomatic arch and it pierces the temporal fascia, supplies the temporalis muscle andzygomatic arch and it pierces the temporal fascia, supplies the temporalis muscle and
ends by anastomosing with the deep auricular branch of the maxillary artery.ends by anastomosing with the deep auricular branch of the maxillary artery.
 Frontal branch :Frontal branch : It runs upwards and forwards to the frontal eminence and ends byIt runs upwards and forwards to the frontal eminence and ends by
anastomosing with the fellow of its opposite side and with the supraorbital andanastomosing with the fellow of its opposite side and with the supraorbital and
supratrochlear arteries. It is very tortuous in its course.supratrochlear arteries. It is very tortuous in its course.
 Parietal branch :Parietal branch : It curves backwards to the posterior part of the side of the headIt curves backwards to the posterior part of the side of the head
superficial to the temporal fascia and ends by anastomosing with the occipital andsuperficial to the temporal fascia and ends by anastomosing with the occipital and
posterior auricular arteries.posterior auricular arteries.

MAXILLARY ARTERY (INTERNAL MAXILLARY)MAXILLARY ARTERY (INTERNAL MAXILLARY)
 It is the larger terminal branch of theIt is the larger terminal branch of the
external carotid artery and begins fromexternal carotid artery and begins from
opposite the neck of the mandible andopposite the neck of the mandible and
the sphenomandibular ligament andthe sphenomandibular ligament and
crossing the inferior alveolar (dental)crossing the inferior alveolar (dental)
nerve it reaches the lower border ofnerve it reaches the lower border of
the lateral pterygoid muscle. Then itthe lateral pterygoid muscle. Then it
ascends upwards crossing superficialascends upwards crossing superficial
to the lower head of the lateralto the lower head of the lateral
pterygoid muscle and then it passespterygoid muscle and then it passes
medially between the two heads of themedially between the two heads of the
lateral pterygoid muscle and enters thelateral pterygoid muscle and enters the
pterygopalatine fossa through thepterygopalatine fossa through the
pterygomaxillary fissure and endspterygomaxillary fissure and ends
dividing into its terminal branches.dividing into its terminal branches.
 The portion of the maxillaryThe portion of the maxillary
artery extending from its origin to theartery extending from its origin to the
lower border of the lateral pterygoidlower border of the lateral pterygoid
muscle constitutes its first part, themuscle constitutes its first part, the
portion extending over the lateralportion extending over the lateral
pterygoid muscle constitutes itspterygoid muscle constitutes its
second or pterygoid part and thesecond or pterygoid part and the
portion extending from between theportion extending from between the
two heads of the lateral pterygoidtwo heads of the lateral pterygoid
muscle to the pterygopalatine fossamuscle to the pterygopalatine fossa
constitutes its third or theconstitutes its third or the
pterygopalatine part.pterygopalatine part.

MAXILLARY ARTERY (INTERNAL MAXILLARY)MAXILLARY ARTERY (INTERNAL MAXILLARY)
 Branches from the first part of theBranches from the first part of the
maxillary artery (five branches) :maxillary artery (five branches) :
 Deep auricularDeep auricular
 Anterior tympanicAnterior tympanic
 Middle meningealMiddle meningeal
 Accessory meningealAccessory meningeal
 Inferior alveolar (dental)Inferior alveolar (dental)
 Branches from the second part (fourBranches from the second part (four
branches) :branches) :
 Deep temporalDeep temporal
 PterygoidPterygoid
 MassetericMasseteric
 BuccalBuccal
 Branches from the third part (sixBranches from the third part (six
branches) :branches) :
 Posterior superior alveolar (dental)Posterior superior alveolar (dental)
 Infra – orbitalInfra – orbital
 Greater palatineGreater palatine
 PharyngealPharyngeal
 Artery of the pterygoid canalArtery of the pterygoid canal
 SphenopalatineSphenopalatine

MAXILLARY ARTERYMAXILLARY ARTERY
 The deep auricular artery is the first branch of the (internal) maxillary artery and ascendsThe deep auricular artery is the first branch of the (internal) maxillary artery and ascends
upwards behind the mandibular joint where it gives a twig to the same. Then it pierces theupwards behind the mandibular joint where it gives a twig to the same. Then it pierces the
cartilage of the pina of the ear and ends by supplying the external surface of the tympaniccartilage of the pina of the ear and ends by supplying the external surface of the tympanic
membrane.membrane.
 The anterior tympanic artery is smaller than the preceding artery and ascends upwards behindThe anterior tympanic artery is smaller than the preceding artery and ascends upwards behind
the mandibular joint and then it enters the tympanic cavity through the pterygotympanic fissure. Inthe mandibular joint and then it enters the tympanic cavity through the pterygotympanic fissure. In
the tympanic cavity it ramifies on the internal surface of the tympanic membrane; bythe tympanic cavity it ramifies on the internal surface of the tympanic membrane; by
anastomosing with the posterior tympanic branch of the stylomastoid artery it forms a vascularanastomosing with the posterior tympanic branch of the stylomastoid artery it forms a vascular
ring around the tympanic membrane. It also anastomoses with the caroticotympanic and thering around the tympanic membrane. It also anastomoses with the caroticotympanic and the
artery of the pterygoid canal.artery of the pterygoid canal.
 The middle meningeal artery is the largest of the meningeal arteries and arises from the firstThe middle meningeal artery is the largest of the meningeal arteries and arises from the first
portion of the maxillary artery.portion of the maxillary artery.
 At its origin it lies between the sphenomandibular ligament and the lateral pterygoid muscle. ThenAt its origin it lies between the sphenomandibular ligament and the lateral pterygoid muscle. Then
as it ascends upwards behind the lateral pterygoid muscle it is encircled by the two roots of theas it ascends upwards behind the lateral pterygoid muscle it is encircled by the two roots of the
auriculotemporal nerve and lies on the tensor palati muscle and is crossed by the chorda tympaniauriculotemporal nerve and lies on the tensor palati muscle and is crossed by the chorda tympani
nerve and then it enters the cranial cavity through the foramen spinosum accompanied by thenerve and then it enters the cranial cavity through the foramen spinosum accompanied by the
meningeal branch of the mandibular nerve (nervous spinosus): then it leaves the nerve and runsmeningeal branch of the mandibular nerve (nervous spinosus): then it leaves the nerve and runs
forwards and laterally in a groove on the squamous part of the temporal bone and then dividesforwards and laterally in a groove on the squamous part of the temporal bone and then divides
into the anterior and posterior branches.into the anterior and posterior branches.
 The anterior branch of the middle meningeal artery crosses the greater wing of the sphenoidThe anterior branch of the middle meningeal artery crosses the greater wing of the sphenoid
bone and then enters in a groove on the antero-inferior angle of the parietal bone; here it dividesbone and then enters in a groove on the antero-inferior angle of the parietal bone; here it divides
into branches which ascend upwards and backwards between the dura mater and the cranium tointo branches which ascend upwards and backwards between the dura mater and the cranium to
the summit of the cranial cavity where it ends by anastomosing with the similar branches from thethe summit of the cranial cavity where it ends by anastomosing with the similar branches from the
opposite side. One of its branches is large and ascends vertically upwards at a distance of aboutopposite side. One of its branches is large and ascends vertically upwards at a distance of about
1.5 cm from the coronal suture.1.5 cm from the coronal suture.
 The posterior branch of the middle meningeal artery runs upwards and backwards in the posteriorThe posterior branch of the middle meningeal artery runs upwards and backwards in the posterior
part of the squamous part of the temporal bone and reaches the parietal bone a little in front of itspart of the squamous part of the temporal bone and reaches the parietal bone a little in front of its
postero-inferior angle and finally divides into branches which supply the dura mater in thepostero-inferior angle and finally divides into branches which supply the dura mater in the
posterior part of the cranium and end by anastomosing with the branches from the opposite side.posterior part of the cranium and end by anastomosing with the branches from the opposite side.

MAXILLARY ARTERYMAXILLARY ARTERY
 Ganglionic. It supplies the trigeminal ganglionGanglionic. It supplies the trigeminal ganglion
 Superficial petrosal. It enters the tympanic cavity through the hiatusSuperficial petrosal. It enters the tympanic cavity through the hiatus
of the greater superficial petrosal nerve and supplies the tympanicof the greater superficial petrosal nerve and supplies the tympanic
cavitycavity
 Superior tympanic. It enters the tympanic cavity through the canalSuperior tympanic. It enters the tympanic cavity through the canal
for the tensor tympani muscle and supplies the tympanic cavity.for the tensor tympani muscle and supplies the tympanic cavity.
 Temporal branches. They come out in the temporal fossa byTemporal branches. They come out in the temporal fossa by
passing through minute foramina in the greater wing of the sphenoidpassing through minute foramina in the greater wing of the sphenoid
bone and ends by anastomosing with deep temporal arteries.bone and ends by anastomosing with deep temporal arteries.
 Orbital. It enters the orbit through the superior orbital fissure andOrbital. It enters the orbit through the superior orbital fissure and
ends by anastomosing with the recurrent meningeal branch of theends by anastomosing with the recurrent meningeal branch of the
lacrimal artery.lacrimal artery.
 Terminal (anterior and posterior).Terminal (anterior and posterior).

 The accessory meningeal artery arises either from the (internal) maxillary or from theThe accessory meningeal artery arises either from the (internal) maxillary or from the
middle meningeal artery and enters the cranial cavity through the foramen ovale. Inmiddle meningeal artery and enters the cranial cavity through the foramen ovale. In
the cranial cavity it supplies branches to the dura mater and the trigeminal ganglion.the cranial cavity it supplies branches to the dura mater and the trigeminal ganglion.
 The inferior alveolar (dental) artery arises from the lower border of the first part of theThe inferior alveolar (dental) artery arises from the lower border of the first part of the
maxillary artery and descends on the medical aspect of the ramus of the mandible tomaxillary artery and descends on the medical aspect of the ramus of the mandible to
the mandibular foramen. It then enters the mandibular canal in company with thethe mandibular foramen. It then enters the mandibular canal in company with the
inferior alveolar (dental) nerve and reaching the level of the first premolar tooth itinferior alveolar (dental) nerve and reaching the level of the first premolar tooth it
ends by dividing into incisive and mental branches. In its course to the mandibularends by dividing into incisive and mental branches. In its course to the mandibular
foramen it intervenes between the ramus of the mandible and the sphenomandibularforamen it intervenes between the ramus of the mandible and the sphenomandibular
ligament and lies posterior to the inferior alveolar (dental) nerve. Just before it entersligament and lies posterior to the inferior alveolar (dental) nerve. Just before it enters
into the mandibular canal it gives out its lingual branch which accompanies the lingualinto the mandibular canal it gives out its lingual branch which accompanies the lingual
nerve and supplies the tongue.nerve and supplies the tongue.
 The mylohyoid branch arises from the inferior alveolar (dental) artery and afterThe mylohyoid branch arises from the inferior alveolar (dental) artery and after
piercing the sphenomandibular ligament it descends on the mylohyoid groovepiercing the sphenomandibular ligament it descends on the mylohyoid groove
together with the mylohyoid nerve. It ramifies on the surface of the mylohyoid muscletogether with the mylohyoid nerve. It ramifies on the surface of the mylohyoid muscle
and anastomoses with the submental branch of the facial artery.and anastomoses with the submental branch of the facial artery.
 The incisive branch of the inferior alveolar artery reaches the median plane byThe incisive branch of the inferior alveolar artery reaches the median plane by
passing below the incisor teeth and ends by anastomosing with fellow of its oppositepassing below the incisor teeth and ends by anastomosing with fellow of its opposite
side. In its course it supplies the incisor teeth.side. In its course it supplies the incisor teeth.
 The mental branch of the inferior alveolar artery comes out through the mentalThe mental branch of the inferior alveolar artery comes out through the mental
foramen and supplies then chin. It anastomoses with the submental and inferior labialforamen and supplies then chin. It anastomoses with the submental and inferior labial
branches of the facial artery.branches of the facial artery.
 The deep temporal branches of the (internal) maxillary artery are anterior andThe deep temporal branches of the (internal) maxillary artery are anterior and
posterior and they ascend to the temporal fossa between the temporalis muscle andposterior and they ascend to the temporal fossa between the temporalis muscle and
the pericranium. They supply the temporalis muscle and anastomose with the middlethe pericranium. They supply the temporalis muscle and anastomose with the middle
temporal artery. The anterior deep temporal artery gives a branch which pierces thetemporal artery. The anterior deep temporal artery gives a branch which pierces the
zygomatic bone and the greater wing of the sphenoid and anastomoses with thezygomatic bone and the greater wing of the sphenoid and anastomoses with the
lacrimal artery.lacrimal artery.
 The pterygoid branches of the (internal) maxillary artery supply the pterygoidThe pterygoid branches of the (internal) maxillary artery supply the pterygoid
muscles.muscles.

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Arterial supply of head & neck