Anatomy of heart dr nikunj shekhada (mbbs,ms gen surg ,dnb cts SR) 11 6-18

1. ANATOMY OF HEART
BY DR NIKUNJ
(CTS RESIDENT STAR HOSPITAL)
(Coordinator:DR PSN)

2. Heart
 A hollow muscular organ, pyramidal in
shape , somewhat larger than a closed fist;
consists of four chambers (right and
left atria, right and left ventricles)
 Wt. = 250-300 grams
 Cardiac Apex is formed by left ventricle and
is directed downwards and forwards to the
left. It lies at the level of the fifth left
intercostal space, 1~2cm medial to the left
midclavicular line (9cm from the midline)
 The apex beat (point of maximum impulse
(PMI)),is the furthermost point outwards
(laterally) and downwards (inferiorly) from
the sternum at which the cardiac impulse
can be felt.

3. POSITION
 Lies within the pericardium in middle mediastinum
 Behind the body of sternum and the 2nd to 6th costal cartilages
 In front of the 5th to 8th thoracic vertebrae

5. Two surfaces
 Sternocostal surface is formed
mainly by the right atrium
and right ventricle, and a lesser
portion of its left is formed by
the left auricle and ventricle. It is
directed forwards and upwards
 Diaphragmatic surface is formed
by the ventricleschiefly
the left ventricle, directed
backwards and downwards, and
rests upon the central tendon of
the diaphragm

6. Three borders
 Right border－vertical, is formed entirely by right atrium
 Left border－round, is mainly formed by the left ventricle
and partly by the left auricle
 Inferior border－horizontal, is formed by the right ventricle
and cardiac apex

7. Four grooves  Coronary sulcus (circular
sulcus) which marks the
division between atria and
ventricles, contains the trunks
of the coronary vessels and
completely encircles the heart
 Interatrial groove
 Interventricular grooves :
 anterior and posterior,

8.  Interventricular grooves－ anterior and
posterior, mark the
division between ventricles (which separates the
RV from the LV),

9. COVERING OF THE HEART
Pericardium – a double-walled sac
around the heart Composed of:
1)A superficial fibrous pericardium
2)A deep two-layer serous pericardium
The parietal layer lines the internal
surface of the fibrous pericardium
The visceral layer or epicardium lines
the surface of the heart
They are separated by the fluid-filled
cavity called the pericardial cavity
Protects and anchors the heart
Prevents overfilling of the heart with
blood
Allows for the heart to work in a
relatively friction-free environment

10. PERICARDIAL LAYER

11. LAYERS OF THE HEART WALL
 Epicardium – visceral pericardium
 Myocardium – cardiac muscle layer
forming the bulk of the heart
 Endocardium – endothelial layer of the
inner myocardial surface

12. ATRIA
 Atria - receiving chambers of the heart
 Receive venous blood returning to heart
 Separated by an interatrial septum (wall)
 Foramen ovale - opening in interatrial septum in
fetus
 Fossa ovalis - remnant of foramen ovale

13. Each atrium has a protruding auricle
Pectinate muscles mark atrial walls
Pump blood into ventricles
Blood enters right atria from superior
and inferior venae cavae and coronary
sinus
Blood enters left atria from
pulmonary veins
Left auricle－projecting to the
right, pectinate muscles in wall
Four inlets－four orifices of
pulmonary veins open through the
posterior wall
One outlet－left atrioventricular
orifice, blood leaves through left
atrioventricular orifice to left
ventricle

14. VENTRICLE
 Ventricles are the discharging
chambers of the heart
 Papillary muscles and trabeculae
carneae muscles mark ventricular
walls
 Separated by an interventricular
septum
 Contains components of the
conduction system
 Right ventricle pumps blood into the
pulmonary trunk
 Left ventricle pumps blood into the
aorta
 Thicker myocardium due to greater
work load
 Pulmonary circulation supplied by
right ventricle is a much low pressure
system requiring less energy output by
ventricle
 Systemic circulation supplied by left
ventricle is a higher pressure system
and thus requires more forceful
contractions

15. Left ventricle
 It’s wall is three times thicker
than that of right ventricle
 One inlet－left atrioventricular orifice
 One outlet－aortic orifice
 Two parts－divided by anterior
cusps of mitral valve
 Inflow tract－rough walls
 Outflow tract – aorti vestibule smooth area
leading to aortic orifice

16. SEPTUMS
 Interatrial septum
 Located between right and left atria
 Contains fossa ovalis
 Interventricular septum Located
between right and left ventricles
upper membranous part ,thick lower
muscular part
 Fibrous skeleton
 Fibrous rings that surround the
atrioventricular, pulmonary, and
aortic orifices
 Left and right fibrous trigons

17. ANTERIOR VIEW

18. POSTERIOR VIEW

19. VALVES
 Heart valves ensure unidirectional blood
flow through the heart
 Composed of an endocardium with a
connective tissue core Two major types
 Atrioventricular (AV) valves lie between the
atria and the ventricles
 R-AV valve = tricuspid valve
 L-AV valve = bicuspid or mitral valve
 AV valves prevent backflow of blood into
the atria when ventricles
contract
 Chordae tendineae anchor AV valves to
papillary muscles of ventricle wall
 Prevent prolapse of valve back into atrium

20. Atrioventricular (AV) valves
• R-AV valve = tricuspid valve
 Guards right atrioventricular orifice Three
triangular cusps: anterior, posterior and
septal, the base of cusps are attached to
fibrous ring surrounding the
atrioventricular orifice
 Chordae tendineae －fine, white,
connective tissue cords,
 attach margin of cusps to papillary
muscles
• L-AV valve = bicuspid or mitral valv
 Mitral valve
 Guards left atrioventricular orifice
 Two triangular cusps－anterior and
posterior with Similar structures to those
of right

21. SEMILUNAR HEART VALVES
 Semilunar valves prevent backflow of blood into the ventricles
 Have no chordae tendinae attachments
 Aortic semilunar valve lies between the left ventricle and the aorta
 Pulmonary semilunar valve lies between the right ventricle and
pulmonary trunk

22. Coronary dominance
 CA that gives post IV branch is supposed to be dominant
 Misleading term as LCA supplies greater part of myocardium, but in 70%
cases post IV is a br of RCA (Rt coronary dominance)
 Coronary arteries - VASAVASORUM arising from aortic sinuses of
Valsalva of Ascending aorta
 Rt CA - from Rt aortic sinus (ant)
 Lt CA from Lt aortic sinus(left post)
 Post Aortic sinus - non coronary
 Max filling of sinuses - in diastole

24. Rt Coronary Artery
• Passes to rt & forwards b/w infundibulum of
rt ven & rt auricle
• Runs downwards in ant AV groove Reaches
inf margin of heart; winds around it to the
diaph surface; runs in post AV groove
• Ends by anastomosing with circumflex br of
LCA -60%
 Rt conus artery- Annulus of Vieussens
 SA Nodal br – 60%
 Ant atrial branches
 Ant ventr branches
 Rt Marginal artery:(Largest br)
 Post ventr branches
 Post IV br arises near CRUX – 70% br of RCA
 Post atrial branches
 AV Nodal artery – 80%

26. Lt Coronary Artery
 Origin: Lt Aortic sinus
 Passes behind infundibulum of Rt ventricle
Bifurcates into Ant IV branch (LAD) &
Circumflex artery
 LAD (Ant IV) artery Continuation of LCA
Extends beyond the apex, ends by
anastamosing with post IV artery (br of
RCA)
Branches:
 Ant ventr brs:
i. Diagonal arteries
ii. Lt Conus artery
 Septal branches
 Circumflex artery : Runs in Ant AV groove
and post AV groove
Terminates by anastamosing with RCA near
crux

29. • 1. Great Cardiac vein
• Begins near apex of heart; acc. Ant IV A &
more proximally cx artery
• Terminates at lt end of coronary sinus
• 2. Middle cardiac vein
• •Accompanies Post IV artery and opens at
termination of coronary sinus
• 3. Small Cardiac vein
• Accompanies rt marginal artery Runs in
AV groove to end into rt end of CS May
open directly into rt atrium
• 4. Oblique Vein of Lt Atrium (of Marshall)
Runs in the post surface of Lt Atrium and
drains into Lt end of Coronary sinus
• 5. Post Vein of Lt Ventricle
• Runs on diaphragmatic surface of Lt
ventricle and ends in middle of
coronarysinus
• 6. Rt Marginal vein
• Accompanies Rt Marginal artery and
drains into Small Cardiac vein or directly
into the Rt Atrium

31. CONDUCTING SYSTEM OF THE
HEART
 Cardiac muscle tissue has intrinsic ability to:
 Generate and conduct impulses
 Signal these cells to contract rhythmically
 A series of specialized cardiac muscle cells
 Sinoatrial (SA) node sets the inherent rate of contraction

32. CONDUCTING SYSTEM OF
THE
HEART
 Sinuatrial node (SA node)
 Called the pacemaker cell (P cell)
 Located at the junction of right atrium and
superior vena cava,
upper part of the sulcus terminalis, under
the epicardium
• Atrioventricular node (AV node)
• Located in the lower part of interatrial
septum just above the orifice of coronary
sinus, under the endocardium Lower part
related to membranous part of
interventricular septum
• Atrioventricular bundle (AV bundle)
• Passes forward through right fibrous trigon
to reach inferior border of membranous part
Divides into right and left branches at upper
border of muscular part of interventricular
septum

33. THANK YOU