Heart Anatomy
Atria
of the Heart
§Approximately the size of fist
§Location
§Superior surface of
diaphragm
§Left of the midline
§Anterior to the
vertebral column, posterior to the sternum
Coverings
of the Heart: Anatomy
§Pericardium – a double-walled sac around the heart
composed of:
A superficial fibrous pericardium
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 pericardial
cavity
§Epicardium – visceral layer of
the serous pericardium
§Myocardium – cardiac muscle layer forming the bulk of the heart
§Endocardium – endothelial layer of the inner myocardial surface
External
Heart: Major Vessels of the Heart (Anterior View)
§Vessels returning
blood to the heart include:
Superior and inferior venae cavae
Right and left pulmonary veins
§Vessels conveying blood away from the heart include:
Pulmonary trunk, which splits into right and left pulmonary
arteries
Ascending aorta (three branches) –
Brachiocephalic
Left common carotid
Subclavian arteries
External
Heart: Vessels that Supply/Drain the Heart (Anterior View)
§Arteries – right and left coronary (in atrioventricular groove),
marginal, circumflex, and anterior interventricular arteries
§Veins – small cardiac, anterior cardiac, and
great cardiac veins
External
Heart: Major Vessels of the Heart (Posterior View)
§Vessels returning blood to the heart include:
Right and left pulmonary veins
Superior and inferior venae cavae
§Vessels conveying blood away from the heart include:
Aorta
Right and left pulmonary arteries
External
Heart: Vessels that Supply/Drain the Heart (Posterior View)
§Arteries – right coronary artery (in atrioventricular groove) and the
posterior interventricular artery (in
interventricular groove)
§Veins – great cardiac vein, posterior vein to left ventricle,
coronary sinus, and middle cardiac vein
Gross
Anatomy of Heart: Frontal Section
§Atria are the receiving
chambers of the heart
§Each
atrium has a protruding auricle
§Pectinate
muscles mark
atrial walls
§Blood
enters right atria from superior and inferior venae cavae and coronary sinus
§Blood
enters left atria from
pulmonary veins
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Ventricles
of the Heart
§Ventricles
are the discharging chambers of the heart
§Papillary muscles and trabeculae carneae muscles mark
ventricular walls
§Right ventricle pumps
blood into the pulmonary trunk
§Left ventricle pumps
blood into the aorta
Pathway
of Blood Through the Heart and Lungs
§Right
atrium à tricuspid
valve à
right ventricle
§Right
ventricle à pulmonary
semilunar valve à
pulmonary arteries à lungs
§Lungs
à pulmonary veins à
left atrium
§Left
atrium à bicuspid
valve à
left ventricle
§Left
ventricle à aortic
semilunar valve à
aorta
§Aorta
à
systemic circulation
Pathway
of Blood Through the Heart and Lungs
Coronary
Circulation
§Coronary circulation is the functional blood supply to
the heart muscle itself
§Collateral routes ensure
blood delivery to heart even if major vessels are occluded
Coronary
Circulation: Arterial Supply
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Heart
Valves
§Heart
valves ensure unidirectional blood flow through the heart
§Atrioventricular
(AV) valves lie between the atria and the ventricles
§AV valves prevent
backflow into the atria when ventricles
contract
§Chordae
tendineae anchor AV valves to papillary
muscles
Heart
Valves
§Semilunar
valves prevent backflow
of blood into the ventricles
§Aortic semilunar valve lies between the left ventricle and the aorta
§Pulmonary semilunar valve lies between the right ventricle and pulmonary
trunk
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Note: Images are subjected for representative purposes only.