2. The scalp is the composite
soft tissue structure that
covers the calvaria.
Extents
Superiorly: Superior nuchal
line.
Laterally: Superior temporal
line and continous with the
fascia over temporalis
muscle.
Anteriorly: Attached to the
upper part of orbicularis
oculi and the overlying skin
of the eyebrow.
3. Skin: Thick, hairy and
rich in sweat glands.
Connective tissue:
Dense, irregular and
highly vascular.
Aponeurosis: Unites
frontalis and
occipitalis muscles.
Loose areolar
tissue:Potential space.
Pericranium:Attaches
to suture lines.
4. Arterial:
External carotid branches:
Superficial temporal artery.
Posterior auricular artery.
Occipital artery.
Internal carotid branches:
supraorbital artery
Supratrochlear artery, both from the
opthalmic artery.
Note:
These branches anastomose freely
with each other therefore scalp
wounds bleed profusely but heal
rapidly when cut.
The arterial walls are attached to the
dense connective tissue of the second
layer of the scalp and tend to be held
open and bleed profusely when cut.
5. The veins run back with the arteries. The
supraorbital and supratrochlear veins drain
into the facial vein
The superficial temporal vein drains into the
retromandibular vein.
Occipital veins drain into the vertebral veins.
The posterior auricular vein drains into the
external jugular vein.
The veins connect with intracranial sinuses
through emissary veins
6. The scalp receives sensory
innervation from:
Supratrochlear Nn (1)
Supraorbital Nn (2)
Zygomaticotemporal Nn (3)
Auriculotemporal Nn (4)
Lesser occipital Nn (C2,C3)
(5)
Greater occipital Nn (C2) (6)
Third occipital Nn (C3) (7)
Facial nerve supplies
occipito-frontalis muscle
7. Lymphatic channels from the posterior half of
the scalp drain to occipital and posterior
auricular nodes
Lymphatic channels from anterior half drain to
the parotid nodes.
The lymph eventually reaches the
submandibular and deep cervical nodes .
8. Made of three components: Neurocranium,
chondrocranium and viscerocranium.
9. Four flat bones
Paired
Parietal(2)
Temporal(4)
Unpaired
Frontal(1)
Occipital(3)
Sutures:
Coronal: between frontal and
parietal
Sagittal: between the two
parietals
Squamosal: between parietal and
temporal
Lambdoid: between parietal and
occipital
10. Made up of the
following:
Occipital bone.
Sphenoid.
Part of temporal bone
(petrous)
Palatine.
It contains various
foramina for the
transmission of
nerves and vessels.
12. Infants:
Inner and outer table.
Outline the other
differences between a
newborn and an adult
skull
Adults: Consists of :
an outer table of compact bone
a layer of spongy bone
(diploe)
an inner table of compact
bone
Note the two layers of Compact
bone (C) and Spongy bone (S)
13.
14. Temporal bones
are situated at the sides and
base of the skull.
The temporal bone supports
that part of the face known as
the temple.
Parts
Each consists of five parts:
Squama temporalis
Mastoid portion
Petrous portion
Tympanic part
Styloid process (temporal)
15. Squama of the temporal
bone
forms the anterior
and upper part of the
bone, and is scale-like,
thin, and translucent.
16. Mastoid portion of the
temporal bone
forms the posterior
part of the temporal
bone.
It has mastoid air cells which act as
a reservoir for air ,equalizing
pressure within the middle ear
in the case of auditory tube
dysfunction.
17. Petrous portion of the temporal
bone or pyramid
is pyramidal and is between
the sphenoid and occipital. It
presents a base, an apex, three
surfaces, and three angles, and
its interior contains essential
parts of the organ of hearing.
18. Tympanic part of the
temporal bone
is a curved plate of
bone lying below the
squama and in front of
the mastoid process.
20. Has the following parts:
Squamous (1)
Orbital process (2)
Nasal process (3)
Note:
The frontal bone articulates with
the paired parietals along the
coronal suture and forms the
forehead
Above the orbit the frontal bone
posseses a supraorbital notch or
if completely surrounded by
bone, a supraorbital foramen.
21. Frontal bone
is a bone in the human
skull that resembles a
cockle-shell in form, and
consists of two portions:
A vertical portion, the
squama frontalis,
corresponding with the
region of the forehead.
An orbital or horizontal
portion, the pars
orbitalis, which enters
into the formation of the
roofs of the orbital and
nasal cavities.
22. I.) Squama frontalis
a.) Frontal suture
b.) Frontal eminence
c.) Superciliary arches
d.) Glabella
e.) Supraorbital foramen
f.) Zygomatic process
g.) Sagittal sulcus
h.) Frontal crest
i.) Foramen cecum
II.) Pars orbitalis
a.) Ethmoidal notch
b.) Lacrimal fossa
c.) Trochlear fovea
d.) Posterior ethmoidal foramen
e.) Anterior ethmoidal foramen
f.) Frontal sinus
g.) Frontonasal duct
23. There are two surfaces of the squama of the frontal bone:
the external surface, and the internal surface.
24. Frontal suture is a dense connective
tissue structure that divides the
two halves of the frontal bone of
the skull in infants and children. It
usually disappears by the age of
six, with the two halves of the
frontal bone being fused together.
If it does not disappear it may be
called a "metopic suture" or
"sutura frontalis persistens." If the
suture is not present at birth
(craniosynostosis) it will cause a
keel-shaped deformity of the skull
called "trigonocephaly."
25. On the frontal bone, on either
side of the frontal suture, about 3
cm. above the supraorbital
margin, is a rounded elevation,
the frontal eminence (tuber
frontale).
These eminences vary in size in
different individuals, are
occasionally unsymmetrical, and
are especially prominent in young
skulls; the surface of the bone
above them is smooth, and
covered by the galea
aponeurotica.
26. On the squama frontalis of
the frontal bone, below the
frontal eminences, and
separated from them by a
shallow groove, are two
arched elevations, the
superciliary arches; these
are prominent medially, and
are joined to one another by
a smooth elevation named
the glabella. The superciliary
arches are more prominent
in men
27. Glabella
is the space between
the eyebrows and
above the nose. It is
slightly elevated, and
joins the two
superciliary ridges.
28. Supraorbital foramen
is a bony elongated path located
above the eye socket and under the
forehead. The supraorbital foramen
lies directly under the eyebrow.
The supraorbital foramen arches
transversely below the superciliary
arches and is the upper part of the
margin of the orbit, thin and
prominent in its lateral two-thirds,
rounded in its medial third, and
presenting, at the junction of these
two portions, the supraorbital notch or
foramen for the supraorbital nerve
and vessels (supraorbital artery and
supraorbital vein.)
29. The supraorbital
margin of the
frontal bone ends
laterally in the
zygomatic
process, which is
strong and
prominent, and
articulates with
the zygomatic
bone.
30. The internal surface of the
squama frontalis of the
frontal bone is concave and
presents in the upper part of
the middle line a vertical
groove, the sagittal sulcus,
the edges of which unite
below to form a ridge, the
frontal crest; the sulcus
lodges the superior sagittal
sinus, while its margins and
the crest afford attachment
to the falx cerebri.
It also is part of the parietal,
and occipital bones.
31. The internal surface of the
squama frontalis of the frontal
bone is concave and presents
in the upper part of the middle
line a vertical groove, the
sagittal sulcus, the edges of
which unite below to form a
ridge, the frontal crest; the
sulcus lodges the superior
sagittal sinus, while its
margins and the crest afford
attachment to the falx cerebri.
32. The frontal crest of the frontal bone
ends below in a small notch which is
converted into a foramen, the foramen
cecum, by articulation with the ethmoid.
This foramen varies in size in different
subjects, and is frequently impervious;
when open, it transmits a vein from the
nose to the superior sagittal sinus. This
has clinical importance in that infections
of the nose and nearby areas can be
transmitted to the meninges and brain
from what is known as the danger
triangle of the face.
33. The orbital or horizontal part of the frontal bone
(pars orbitalis) consists of two thin triangular plates,
the orbital plates, which form the vaults of the
orbits, and are separated from one another by a
median gap, the ethmoidal notch.
34. Ethmoidal notch
separates the two orbital
plates; it is quadrilateral, and
filled, in the articulated skull,
by the cribriform plate of the
ethmoid.
The margins of the notch
present several half-cells
which, when united with
corresponding half-cells on the
upper surface of the ethmoid,
complete the ethmoidal air
cells.
35. The inferior surface of each
orbital plate of the frontal
bone is smooth and
concave, and presents,
laterally, under cover of
the zygomatic process, a
shallow depression, the
lacrimal fossa (or fossa for
lacrimal gland), for the
lacrimal gland.
36. Near the nasal part of the
interior surface of the
frontal bone is a
depression, the
trochlear fovea, or
occasionally a small
trochlear spine, for the
attachment of the
cartilaginous pulley of
the Obliquus oculi
superior.
37. Lateral to either olfactory
groove are the internal
openings of the anterior and
posterior ethmoidal foramina
(or canals).
Posterior ethmoidal foramen
opens at the back part of this
margin under cover of the
projecting lamina of the
sphenoid, and transmits the
posterior ethmoidal vessels
and nerve.
38. Lateral to either olfactory groove
are the internal openings of the
anterior and posterior ethmoidal
foramina (or canals).
Anterior ethmoidal foramen,
situated about the middle of the
lateral margin of the olfactory
groove, transmits the anterior
ethmoidal vessels and the
nasociliary nerve; the nerve runs
in a groove along the lateral edge
of the cribriform plate to the slit-
like opening above mentioned.
39. Frontal sinuses, situated behind the superciliary arches, are rarely
symmetrical, and the septum between them frequently deviates to one or
other side of the middle line.
Their average measurements are as follows: height, 3 cm.; breadth, 2.5
cm.; depth from before backward, 2.5 cm.
40. The frontal air sinuses are lined by mucous
membrane, and each communicates with the
corresponding nasal cavity by means of a passage
called the frontonasal duct.
41. On the external
surface , each possess
a Superior, and
Inferior Temporal
Line, to which the
muscle temporalis is
attached.
42. Parietal bones
are bones in the human skull and
form, by their union, the sides and
roof of the cranium. Each bone is
irregularly quadrilateral in form, and
has two surfaces, four borders, and
four angles.
Outer
Inner
43. Sagittal border, the longest and thickest, is dentated and
articulates with its fellow of the opposite side, forming the
sagittal suture.
Frontal border is deeply serrated, and bevelled at the expense
of the outer surface above and of the inner below; it
articulates with the frontal bone, forming half of the coronal
suture. The point where the coronal suture intersects with
the sagittal suture forms a T-shape and is called the
bregma.
Occipital border, deeply denticulated, articulates with the
occipital, forming half of the lambdoid suture. That point
where the sagittal suture intersects the lambdoid suture is
called the lambda, because of its resemblance to the
Greek letter.
Squamous border is divided into three parts: of these:
the anterior is thin and pointed, bevelled at the
expense of the outer surface, and overlapped by
the tip of the great wing of the sphenoid;
the middle portion is arched, bevelled at the
expense of the outer surface, and overlapped by
the squama of the temporal;
the posterior part is thick and serrated for
articulation with the mastoid portion of the
temporal.
44. Frontal angle is practically a right angle, and
corresponds with the point of meeting of the sagittal
and coronal sutures; this point is named the bregma; in
the fetal skull and for about a year and a half after birth
this region is membranous, and is called the anterior
fontanelle.
Occipital angle is rounded and corresponds with the
point of meeting of the sagittal and lambdoidal
sutures—a point which is termed the lambda; in the
fetus this part of the skull is membranous, and is called
the posterior fontanelle.
Mastoid angle is truncated; it articulates with the
occipital bone and with the mastoid portion of the
temporal, and presents on its inner surface a broad,
shallow groove which lodges part of the transverse
sinus. The point of meeting of this angle with the
occipital and the mastoid part of the temporal is named
the asterion.
Sphenoidal angle, thin and acute, is received into the
interval between the frontal bone and the great wing of
the sphenoid. Its inner surface is marked by a deep
groove, sometimes a canal, for the anterior divisions of
the middle meningeal artery.
45.
46. Has three parts which sorround
foramen magnum:
The squamous part(posteriorly) - 1
The occipital condyles(lateral) - 2
The basilar part(anteriorly) – 3
Externally, the squamous portion of
the bone possesses supreme,
superior and inferior nuchal lines to
which the muscles at the back of the
neck are attached.
The occipital condyles articulate
with the first cervical vertebrae (the
atlas).
Lateral to each occipital condyle are
the condylar fossae and foramen
while the hypoglossal canal is
medial to them.
47. Occipital bone,
a saucer-shaped membrane
bone situated at the back and
lower part of the cranium, is
trapezoid in shape and curved on
itself. It is pierced by a large oval
aperture, the foramen magnum,
through which the cranial cavity
communicates with the vertebral
canal.
The curved, expanded plate
behind the foramen magnum is
named the squama occipitalis.
The thick, somewhat quadrilateral
piece in front of the foramen is
called the basilar part of occipital
bone.
On either side of the foramen are
the lateral parts of occipital bone.
48. Parts
Body
Greater wing
Lesser wing
Pterygoid plates(Medial and Lateral)
Body lodges pitituary fossa
(sella turcica)
Fissures and foramina
superior-orbital fissure
Rotundum
Ovale
Spinosum
49.
50. Parts
1. Alveolar process.
2. The body.
3. Zygomatic process.
4. The frontal process -
joins the frontal
bone.
Contains maxillary air
sinus
51. I.) Body of maxilla
II.) Maxillary sinus
A.)Surfaces of body
1.) Anterior
a.) Incisive fossa
b.) Canine fossa
c.) Infraorbital foramen
d.) Anterior nasal spine
2.) Infratemporal
a.) Alveolar canals
b.) Maxillary tuberosity
3.) Orbital
a.) Infraorbital groove
b.) Infraorbital canal
4.) Nasal
a.) Pterygopalatine canal
Processes
1.) Zygomatic process
2.) Frontal process
a.) Agger nasi
b.) Anterior lacrimal
crest
3.) Alveolar process
4.) Palatine process
a.) Incisive foramen
b.) Incisive canals
c.) Foramina of
Scarpa
d.) Premaxilla e.)
Anterior nasal spine
52. Maxilla
is a fusion of two bones along the
palatal fissure that form the upper jaw.
This is similar to the mandible, which is
also a fusion of two halves at the mental
symphysis.
Function
The alveolar process of the maxilla
holds the upper teeth, and is referred to
as the maxillary arch. The maxilla
attaches laterally to the zygomatic bones
(cheek bones).
The maxilla assists in forming the
boundaries of three cavities:
the roof of the mouth
the floor and lateral wall of the nasal
antrum
the floor of the orbit
The maxilla also enters into the
formation of two fossae: the
infratemporal and pterygopalatine, and
two fissures, the inferior orbital and
pterygomaxillary.
53. Body of the Maxilla
is somewhat
pyramidal in shape, and
contains a large cavity,
the maxillary sinus
(antrum of Highmore).
It has four surfaces - an
anterior, a posterior or
infratemporal, a superior
or orbital, and a medial
or nasal.
54. Maxillary sinus (or Antrum of
Highmore)
is the largest of the
paranasal sinuses, and is
pyramidal in shape.
55. 1.) Anterior
a.) Incisive fossa
b.) Canine fossa
c.) Infraorbital foramen
d.) Anterior nasal spine
2.) Infratemporal
a.) Alveolar canals
b.) Maxillary tuberosity
3.) Orbital
a.) Infraorbital groove
b.) Infraorbital canal
4.) Nasal
a.) Pterygopalatine canal
56. Anterior surface
is directed forward and
lateral ward. It presents at its
lower part a series of
eminences corresponding to
the positions of the roots of the
teeth. Just above those of the
incisor teeth is a depression,
the incisive fossa, which gives
origin to the Depressor alae
nasi; to the alveolar border
below the fossa is attached a
slip of the Orbicularis oris;
above and a little lateral to it,
the Nasalis arises.
57. On the anterior surface of the
maxilla, just above the
eminences corresponding to
the incisor teeth is a
depression, the incisive fossa,
which gives origin to the
Depressor alæ nasi; to the
alveolar border below the fossa
is attached a slip of the
Orbicularis oris; above and a
little lateral to it, the Nasalis
arises.
58. Lateral to the incisive fossa is
another depression, the
canine fossa; it is larger and
deeper than the incisive
fossa, and is separated from
it by a vertical ridge, the
canine eminence,
corresponding to the socket
of the canine tooth; the
canine fossa gives origin to
the Caninus.
59. Above the canine fossa is
the infraorbital
foramen, the end of the
infraorbital canal; it
transmits the
infraorbital artery,
vein, and infraorbital
nerve.
60. Medially, the anterior surface
of the maxilla is limited by a
deep concavity, the nasal
notch, the margin of which
gives attachment to the
Dilatator naris posterior and
ends below in a pointed
process, which with its fellow
of the opposite side forms
the anterior nasal spine.
61. Infratemporal surface
is convex, directed
backward and lateralward, and
forms part of the infratemporal
fossa.
It is separated from the anterior
surface by the zygomatic
process and by a strong ridge,
extending upward from the
socket of the first molar tooth.
It is pierced about its center by
the apertures of the alveolar
canals, which transmit the
posterior superior alveolar
vessels and nerves.
62. The infratemporal
surface of the maxilla
is pierced about its
center by the apertures
of the alveolar canals,
which transmit the
posterior superior
alveolar vessels and
nerves.
63. At the lower part of the
infratemporal surface of the
maxilla is a rounded eminence,
the maxillary tuberosity,
especially prominent after the
growth of the wisdom tooth; it is
rough on its lateral side for
articulation with the pyramidal
process of the palatine bone and
in some cases articulates with the
lateral pterygoid plate of the
sphenoid.
It gives origin to a few fibers of
the Pterygoideus internus.
64. Orbital surface
is smooth and
triangular, and forms
the greater part of the
floor of the orbit.
65. Near the middle of the posterior
part of the orbital surface of the
maxilla is the infraorbital groove
(or sulcus), for the passage of
the infraorbital vessels and nerve.
The groove begins at the middle
of the posterior border, where it is
continuous with that near the
upper edge of the infratemporal
surface, and, passing forward,
ends in a canal, which subdivides
into two branches.
66. One of the canals of the orbital surface of the
maxilla, the infraorbital canal, opens just
below the margin of the orbit.
67. The nasal surface presents
a large, irregular opening
leading into the maxillary
sinus. At the upper border of
this aperture are some
broken air cells, which, in the
articulated skull, are closed
in by the ethmoid and
lacrimal bones.
68. Greater palatine canal (or
pterygopalatine canal)
is a passage in the skull
that transmits the greater
palatine artery, vein, and
nerve between the
pterygopalatine fossa and
the oral cavity.
69. A.) Four processes
1.) The zygomatic process
2.) The frontal process
a.) Agger nasi
b.) Anterior lacrimal crest
3.) The alveolar process
4.) The palatine process
a.) Incisive foramen
b.) Incisive canals
c.) Foramina of Scarpa
d.) Premaxilla
e.) Anterior nasal spine
70. The zygomatic process of the maxilla (malar process) is a rough
triangular eminence, situated at the angle of separation of the
anterior, zygomatic, and orbital surfaces.
71. Frontal process of the maxilla (nasal
process) is a strong plate, which
projects upward, medialward, and
backward, by the side of the nose,
forming part of its lateral boundary.
Its lateral surface is smooth, continuous
with the anterior surface of the body, and
gives attachment to the Quadratus labii
superioris, the Orbicularis oculi, and the
medial palpebral ligament.
72. The agger nasi (from agger meaning "mound or heap") is
a small ridge on the lateral side of the nasal cavity. It is
located midway at the anterior edge of the middle nasal
concha, directly above the atrium of the middle meatus. It
is formed by a mucous membrane that is covering the
ethmoidal crest of the maxilla.
It is also called the nasoturbinal concha and the nasal
ridge.
73. The lateral margin of the lacrimal fossa is named the
anterior lacrimal crest, and is continuous below with the
orbital margin; at its junction with the orbital surface is a
small tubercle, the lacrimal tubercle, which serves as a
guide to the position of the lacrimal sac.
74. Form part of medial orbital wall
Medial surface forms a small portion of the
nasal passage
Posterior lacrimal crest divides this surface into
an orbital plate and the lacrimal sulcus.
75. The alveolar process is the thickened ridge of bone that contains the tooth sockets
on bones that bear teeth. It is also referred to as the alveolar bone. In humans, the
tooth-bearing bones are the maxilla and the mandible.
76. Separates oral and nasal cavities
Right and left joined by inter-palatine suture
Parts
Horizontal
Vertical
Foramina
Greater palatine
Lesser palatine
77. The palatine process of the maxilla (palatal process), thick and strong, is horizontal
and projects medialward from the nasal surface of the bone.
It forms a considerable part of the floor of the nose and the roof of the mouth and is
much thicker in front than behind.
78. When the two maxillæ are articulated, a funnel-shaped
opening, the incisive foramen, is seen in the middle line,
immediately behind the incisor teeth.
79. In the opening of the incisive foramen, the orifices of two lateral
canals are visible; they are named the incisive canals or
foramina of Stenson.
80. In the maxilla, occasionally two additional canals are present in the middle
line of the palatine process; they are termed the foramina of Scarpa, and
when present transmit the nasopalatine nerves, the left passing through the
anterior, and the right through the posterior canal.
81. The premaxilla is a pair of small cranial bones at the very tip
of the jaws of many animals, usually bearing teeth, but not
always. They are connected to the maxilla and the nasals.
82. Orbital process
Zygomaticofacial
foramen
Zygomaticotemporal
foramen
Zygomaticoörbital
foramina
Parts:
A temporal process.
An orbital part bounding the lateral
and inferior margins of the orbit.
A maxillary part joining the maxilla.
The body from which the three parts
orbital, temporal and maxillary
extend.
What forms the zygomatic arch?
Processes:
Marginal process
Temporal process
The maxillary process
83. Zygomatic bone (malar bone)
is a paired bone of the human
skull. It articulates with the maxilla,
the temporal bone, the sphenoid
bone and the frontal bone. It forms
part of the orbit and is commonly
referred to as the cheekbone. It is
situated at the upper and lateral
part of the face: it forms the
prominence of the cheek, part of
the lateral wall and floor of the
orbit, and parts of the temporal and
infratemporal fossae. It presents a
malar and a temporal surface; four
processes, the frontosphenoidal,
orbital, maxillary, and temporal;
and four borders.
84.
85. Orbital process of
the zygomatic
bone
is a thick,
strong plate,
projecting
backward and
medialward from
the orbital
margin.
86. The malar surface of the
zygomatic bone is convex
and perforated near its
center by a small aperture,
the zygomaticofacial
foramen, for the passage of
the zygomaticofacial nerve
and vessels; below this
foramen is a slight
elevation, which gives origin
to the Zygomaticus.
87. Near the center of the
temporal surface of the
zygomatic bone is the
zygomaticotemporal
foramen for the
transmission of the
zygomaticotemporal
nerve.
88. On the orbital process of the
zygomatic bone are seen
the orifices of two canals,
the zygomaticoörbital
foramina; one of these
canals opens into the
temporal fossa, the other on
the malar surface of the
bone; the former transmits
the zygomaticotemporal, the
latter the zygomaticofacial
nerve.
89. Connects the facial
and cranial skeletons
Plates
Crista galli(1)
Cribriform (2)
Perpendicular
Orbital plate
Projections
Superior and inferior
nasal conchae
90. Is a single flat bone located in the mid-sagittal plane. It
articulates with the perpendicular plate of the ethmoid
superiorly and together aid in forming the nasal
septum, aligned perpendicularly and divides the the
nasal aperture into the the left and right nasal passages.
In addition to the Perpendicular portion, superiorly the
Vomer mushrooms out into a pair of Alae which
terminate and articulate with the sphenoid in a heart
shaped process.
Inferiorly the Vomer rests on both the maxillae and the
palatines.
92. Jaw
is either of the two opposable structures forming, or near the entrance
to, the mouth.
Jaws
is also broadly applied to the whole of the structures constituting the
vault of the mouth and serving to open and close it.
In vertebrates, the lower jaw, dentary or mandible is the mobile
component that articulates at its posterior processes, or rami (singular
ramus), with the temporal bones of the skull on either side; the word jaw
used in the singular typically refers to the lower jaw.
93. A.)Body
a.) Symphysis menti
b.) Mental protuberance
c.) Mental foramen
d.) Mylohyoid line
B.)Ramus
a.) Mandibular foramen
b.) Mylohyoid groove
c.) Mandibular canal
d.) Angle
e.) Coronoid process
f.) Condyloid process
g.) Mandibular notch
94. Mandible (from Latin mandibŭla, "jawbone") or inferior maxillary bone is,
together with the maxilla, the largest and strongest bone of the
face[citation needed]. It forms the lower jaw and holds the lower teeth
in place.
Body of the mandible
Symphysis menti
Mental protuberance
Mental foramen
Mylohyoid line
95. The external surface of the mandible is marked in the median line by a faint ridge,
indicating the symphysis menti or line of junction of the two pieces of which the
bone is composed at an early period of life.
This ridge divides below and encloses a triangular eminence, the mental
protuberance, the base of which is depressed in the center but raised on either side
to form the mental tubercle.
It serves as the origin for the Geniohyoid and the Genioglossus.
96. Symphysis of the external surface of the mandible divides below and
encloses a triangular eminence, the Mental protuberance, the base of
which is depressed in the center but raised on either side to form the
mental tubercle.
97. Mental foramen
is one of two holes ("foramina") located on the anterior surface of the mandible.
It permits passage of the mental nerve and vessels. The mental foramen descends
slightly in edentulous individuals
98. Extending upward and backward on either side from the lower part of
the symphysis of the Mandible is the mylohyoid line, which is the
origin of the mylohyoid muscle; the posterior part of this line, near the
alveolar margin, gives attachment to a small part of the Constrictor
pharyngis superior, and to the pterygomandibular raphé.
99. The ramus of the mandible (perpendicular portion) is
quadrilateral in shape, and has two surfaces, four borders, and
two processes.
100. The Mandibular foramen is an opening on the internal surface
of the ramus (posterior and perpendicularly oriented part of the
mandible) for divisions of the mandibular vessels and nerve to
pass.
101. • Behind this groove is a rough
surface, for the insertion of the
Pterygoideus internus.
• The margin of the mandibular
foramen is irregular; it presents in
front a prominent ridge, surmounted
by a sharp spine, the lingula
mandibulæ, which gives attachment
to the sphenomandibular ligament;
at its lower and back part is a notch
from which the mylohyoid groove
runs obliquely downward and
forward, and lodges the mylohyoid
vessels and nerve.
102. Mandibular canal
runs obliquely downward and
forward in the ramus, and then
horizontally forward in the body,
where it is placed under the
alveoli and communicates with
them by small openings.
On arriving at the incisor teeth, it
turns back to communicate with
the mental foramen, giving off two
small canals which run to the
cavities containing the incisor
teeth.
Carries branches of inferior
alveolar nerve and artery. Is
continuous with the mental
foramen (opents onto front of
mandible) and mandibular
foramen (on medial aspect of
ramus).
103. At the junction of the lower border of the ramus of the mandible with the
posterior border is the angle of the mandible, which may be either
inverted or everted and is marked by rough, oblique ridges on each side, for
the attachment of the Masseter laterally, and the Pterygoideus internus
medially; the stylomandibular ligament is attached to the angle between
these muscles.
104. Coronoid process
is a thin, triangular eminence, which is flattened from side to side and varies in
shape and size.
Its anterior border is convex and is continuous below with the anterior border of the
ramus.
Its posterior border is concave and forms the anterior boundary of the mandibular
notch.
Its lateral surface is smooth, and affords insertion to the Temporalis and Masseter.
Its medial surface gives insertion to the Temporalis, and presents a ridge which
begins near the apex of the process and runs downward and forward to the inner
side of the last molar tooth.
Between this ridge and the anterior border is a grooved triangular area, the upper
part of which gives attachment to the Temporalis, the lower part to some fibers of the
Buccinator.
105. The condyle presents an articular surface for articulation with the
articular disk of the temporomandibular joint; it is convex from before
backward and from side to side, and extends farther on the posterior
than on the anterior surface.
Its long axis is directed medialward and slightly backward, and if
prolonged to the middle line will meet that of the opposite condyle
near the anterior margin of the foramen magnum.
At the lateral extremity of the condyle is a small tubercle for the
attachment of the temporomandibular ligament.
is thicker than the
coronoid, and consists of
two portions: the condyle,
and the constricted portion
which supports it, the neck.
106. The upper border of the ramus of mandible is thin, and is surmounted by
two processes, the coronoid process in front and the condyloid
process behind, separated by a deep concavity, the mandibular notch.
110. FORAMEN LOCATION STRUCTURES
TRANSMITTED
Magnum (6) Between the
squamous and
basilar part of
occipital bone.
spinal cord, meninges,
spinal arteries, spinal
accessory nerve,
vertebral arteries,
emissary veins,
cervical meningeal
nerve.
Jugular foramen (7) Anterolateral to
Hypoglossal canal, at
the level of the
styloid process
Glossopharyngeal
nerve, internal jugular
vein, vagus nerve,
emissary veins and the
spinal accessory nerve
Carotid canal (8) Anterior to the
jugular foramen
Internal carotid artery
and nerve plexus and
emissary vein
Lacerum (9) Between the basilar
part of occipital
bone, the body of
sphenoid and the
petrouspart of
temporal bone
Covered by cartilage in
life.
Related to the internal
carotid artery
superiorly
112. FORAMEN LOCATION STRUCTURES
TRANSMITTED
Superior orbital
fissure
Between the lesser and greater wing of sphenoid Ophthalmic,
oculomotor, trochlear
and abducens nerve
ophthalmic veins
Inferior orbital fissure Orbital part of maxillae Continuation of
maxillary nerve
Optic canal Lesser wing of sphenoid Optic nerve, meninges,
ophthalmic artery
114. 1. The scalp enjoys a rich blood supply in which there is an exentesive antero-
posterior and right-left anastomosis
Thus wounds of the scalp bleed profusely but heal very rapidly. The blood vessels
are located in the connective tissue layer. The tunica adventitia of the vessels
merges with the connective tissue. When lacerated, the elastic recoil of
theconnective tissue holds the vessels open.
2. The veins of the scalp are connected to the intracranial venous sinuses by
emissary veins. Therefore
• Raised intracranial pressure may be manifested in dilatation of scalp veins
• Infections or malignancies can spread between intracranial and extracranial sites
3. The aponeurosis connects the frontalis and occipitalis muscles. If it is cut
coronally. contraction of the muscle usually gapes the wound.
4. The layer of loose connective tissue constitutes the plane of avulsion. The
superficial three layers usually peel off as a unit with their blood vessels. Therefore
such injuries still heal well. Fluid, for example, that accumulates in this layer
spreads over the entire extent of the aponeurosis reaching the eyelid and presents
as a black eye.
5. The pericranium, that is the periosteum of the skull bones is tightly adherent to
the sutures. Accordingly, blood that accumulates and clots i.e cephalohematoma is
confined to one bone for example the right parietal.
115. 1. The skull has weak points e.g. The pterion: Meeting point of
frontal, parietal, temporal and greater wing of sphenoid. This
point overlies the anterior branch of middle meningeal in the epi
dural space. Therefore, fractures commonly tear the artery causing
epidural hematoma.
Squamous temporal
Orbital roof
Nasal bones
Cribriform plate
These points are easily fractured causing injury to the underlying
organs.
2. In fractures of cribriform plate and petrous temporal bone,
meninges and mucous membranes may be torn causing CSF to
leak through the nose (CSF rhinorrhoea) or ear (CSF otorrhoea)
116. 1. Give an account of the parts of the bones that
form the skull. Make reference to weak points
on the skull.
2. Tabulate the foramina of the skull, in which
bone they are found and what structures they
transmit.
3. Describe the extent, layers, blood supply,
innervation, lymphatic drainage and applied
anatomy of the scalp.
117. 3. The foramina have rigid boundaries. So , in space
occupying lesions, contents of the foramina are often
compressed e.g jugular foramen syndrome in which
cranial nerves and jugular veins are compressed
causing neurological and vascular symptoms.
4. Abscence of diploe in babies facilitates moulding.
5. Fontanelles and sutures in newborns permit brain
growth, delayed closure suggests retarded skeletal
growth or raised intracranial pressure.
119. Muscles of the face share four main
characteristics :
• They are generally subcutaneous
• They are arranged around the orifices of the
face, thus acting as sphincters and dilators
• They are innervated by facial nerve
• They are embryologically derived from the 2
nd branchial arch
120.
121.
122. Source Region Region
Facial Artery External carotid Mandibular, maxillary,
zygomatic and nasal
parts
Supratrochlear
Supraorbital
Opthalmic- internal carotid Forehead
Zygomatico-facial
Zygomatico- temporal
Infraorbital
Maxillary - External carotid Side of face, upper jaw
Mental Maxillary – External carotid Lower jaw
The veins accompany the arteries and intimately join the external and internal jugular
veins
The face receives a rich blood supply from both internal and external carotid arteries
through various arteries:
123. • From the lower lip and chin – submental
nodes
• From the forehead and cheeks –
Submandibular nodes
• Around the ear – Pre –auricular nodes
124. Sensory innervations is
derived from the divisions of
the trigeminal nerve
Forehead- Ophthalmic
Maxillary region –
Maxillary
Mandibular region and
anterior to the ear –
Mandibular
Motor innervation is
provided by branches of the
facial nerve
125. The face has a rich blood supply characterized by extensive
anastomosis . Therefore lacerations bleed profusely and heal
rapidly. Muscle contraction may gape wounds and hold vessels
open, worsening the bleeding.
Veins of the upper face including the upper lips, nose, eyelids and
forehead communicate with the cavernous venous sinus through:
Ophthalmic veins
Deep facial veins
Those of the forehead also communicate with the superior sagittal
sinus through an emissary vein in foramen cecum.
These communications are potential routes for spread of infection
from the face to the intracranial structure. For this reason, this part
of the face is considered the danger area of the face.
126. Injury to the facial nerve paralyses muscles of
facial expression. Such paralysis is
characterized by:
Deviation of the face to the normal side when the
patient opens the mouth as in yawning or smiling
Accumulation of food in the vestibule of the mouth –
between the cheeks and teeth.
Inability to close the eye causing corneal exposure
and drying, hence vulnerability to ulceration
Obliteration of nasolabial groove
Loss of the corneal reflex on the affected side
127. Enumerate briefly on the sensory innervation,
blood supply, lymphatic drainage and main
characteristics of the muscles of the face
128. Human Head
In anatomy, the head of an animal is the rostral part (from
anatomical position) that usually comprises the brain, eyes, ears,
nose, and mouth (all of which aid in various sensory functions,
such as sight, hearing, smell, and taste). Some very simple
animals may not have a head, but many bilaterally symmetric
forms do.
129. Human skull
The skull is divided into
the cranium (all the skull
bones except the mandible)
and the mandible (or
jawbone). One feature that
distinguishes mammals
and non-mammals is that
there are also three ear
bones (called ossicles):
malleus (hammer)
incus (anvil)
stapes (stirrup)
130.
131.
132.
133.
134.
135.
136.
137.
138. Ossicles (also called auditory ossicles) are the three smallest bones in
the human body. They are contained within the middle ear space and
serve to transmit sounds from the air to the fluid filled labyrinth
(cochlea). The absence of the auditory ossicles would constitute a
moderate to severe hearing loss.
Malleus Incus Stapes
139. The cranium can be divided into a skull cap (or calvarium) and base.
The cranium consists of several bones which fuse together at
junctions called sutures. Several sutures join to form a pterion.
This process of bone fusion occurs in utero to protect the most
important organ in the body, the brain. Although most fusing is
complete before birth, there are large areas of fibrous tissue (called
fontanelles) where fusion is incomplete until puberty.
Facial and skull bones formed:
two maxillae (one on each side of the head) that cover the inferior and
medial to the eye socket (or orbit)
two zygomatic bones, inferior and lateral to the orbit
two temporal bones, covering an area where the ears are located
a single frontal bone, superior to the orbit
two parietal bones, posterior to the frontal bone and superior to the
temporal bone
an occipital bone at the back of the head
several more internal bones which are not easily seen which are
a sphenoid bone, ethmoid bone, two lacrimal bones, two nasal
bones, two palatine bones, two nasal conchae, a vomer
140. The point corresponding with the
posterior end of the
sphenoparietal suture is named
the pterion.
Location
It is situated about 3 cm. behind,
and a little above the level of the
zygomatic process of the frontal
bone.
It marks the junction between
four bones:
the parietal bone
the temporal bone
the sphenoid bone
the frontal bone
141. In human anatomy, a fontanelle
(or fontanel) is one of two "soft
spots" on a newborn human's
skull. There are, however, two
more fontanelles of interest, the
mastoid fontanelle, and the
sphenoidal fontanelle.
Fontanelles are soft spots on a
baby's head which, during birth,
enable the soft bony plates of the
skull to flex, allowing the head to
pass through the birth canal.
Fontanelles are usually
completely hardened by a child's
second birthday, and will
eventually form the sutures of the
neurocranium.
142.
143.
144.
145.
146. The first cervical vertebra is the
atlas and is considered an
atypical cervical vertebra because
it has no body or spinous process.
It articulates with the occipital
condyles of the skull above it and
with the superior articular
processes of the axis below it. It
also articulates with the dens of
the axis below. If viewed from
above, you can identify the
following parts of the atlas:
Anterior arch
Anterior tubercle
Superior articular process
(articulate with the occipital
condyle of the skull)
Foramen transversarium
Transverse process
Posterior arch
Posterior tubercle
Vertebral canal (continuous with
the foramen magnum at the base
of the skull). The brain stem
continues inferiorly as the spinal
cord at the margin of the foramen
magnum.
147. The axis is the second
cervical vertebra. This
vertebral is also called an
atypical vertebra because it
has an upward projection
called the dens that
articulates with the inner
aspect of the anterior arch
of the atlas just posterior to
the anterior tubercle. Some
of the identifiable parts are
the:
dens
body
superior articular process
transverse process with its
vertebral foramen
pedicle
lamina
bifid spine
148. The 3rd, 4th, 5th, and 6th
cervical vertebrae are known
as the typical cervical
vertebrae because they all
have the same characteristics
and except for the foramen for
the vertebral artery similar to
other typical vertebrae of the
spinal cord. These
characteristics are:
body
pedicle
foramen for vertebral artery
superior articular process
lamina
spinous process (bifid in case
of cervical vertebrae)
vertebral canal
transverse process (consists of
a groove that carries a cervical
spinal nerve and, of course the
foramen for the vertebral
artery)
149. The 7th cervical vertebra starts to pick up
characteristics of the upper thoracic vertebrae.
Differences from other cervical vertebrae
no foramen for the vertebral artery
After the vertebral artery arises from the subclavian artery, it
enters the transverse foramen of the 6th cervical vertebra
bypassing the 7th
may not have a bifid spinous process
the spinous process of the 7 cervical vertebra is
longer than the other cervical vertebrae
it is not buried under the ligamentum nuchae of the
neck so it is easy to see and to palpate and is called
the vertebra prominens
can serve as a surface landmark demarcating the neck
(cervical) from the thoracic regions of the body.
151. It lies in the pterygopalatine fossa
pterygopalatine
ganglion
152. •From the maxillary nerve which arises from the
trigeminal ganglion
Sensory root
•From the greater superficial petrosal nerve ( from the
facial nerve) which arises from the superior salivary
nucleus
parasympathetic root
•From the deep petrosal nerve ( from the nerve plexus
around the internal carotid artery ) which arises from the
superior cervical gaglion
Sympathetic root
153. N.B.
The sympathetic and parasympathetic roots reach the ganglion
through the nerve of the pterygoid canal which is formed by the
union of deep petrosal nerve (sympathetic) & greater superifical
petrosal nerve (parasympathetic)
Sensory
roots
Maxillary
nerve
Greater superficial petrosal
(parasympathetic)
Deep petrosal
(sympathetic)
Autonomic root
(Nerve to pterygoid canal)
(Vidian Nerve)
Pterygopalatine
Ganglion
155. Orbital branches - Inferior orbital fissure.
supply orbital wall, sphenoidal and ethmoidal sinuse
Greater and lesser palatine nerves-Supply palatine, tonsil, nasal cavity
Originate from geniculate ganglion of facial nerve(VII) in temporal bone.
In palatine canal, gives origin to posterior inferior nasal nerves, which contribute to
innervation of lateral nasal wall
Greater petrosal nerve enter pterygoid canal and becomes nerve of pteygoid
156. N.B.
The sympathetic and parasympathetic roots reach the ganglion
through the nerve of the pterygoid canal which is formed by the
union of deep petrosal nerve (sympathetic) & greater superifical
petrosal nerve (parasympathetic)
Sensory
roots
Maxillary
nerve
Greater superficial petrosal
(parasympathetic)
Deep petrosal
(sympathetic)
Autonomic root
(Nerve to pterygoid canal)
(Vidian Nerve)
Pterygopalatine
Ganglion
157.
158. A patient needs to be taken to intensive care, but
before he can be transferred, the consultant
asks you, the ICU SpR, to place a central line in
his neck. Where would you like to put it?
(a) External jugular vein
(b) Internal jugular vein
(c) Superior vena cava
(d) Brachiocephalic vein
(e) Subclavian vein
159. Superficial structures
from the lateral view of
the neck.
sternomastoid
trapezius
occipital lymph nodes
(on)
retroauricular lymph
nodes (ran)
superficial cervical lymph
nodes (scn)
submental lymph nodes
(smn)
buccal lymph nodes (bn)
parotid lymph nodes (pn)
submandibular lymph
nodes (not labeled but
uner angle of mandible)
