Human AnatomyBio 22

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Human Anatomy-Bio 22 Lecture 20 The Cardiovascul
ar System, The Heart Presented By Tealia Da
vis, MSc
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The Heart Anatomy
Approximately the size of your fist
Location Superior surface Left of the mid
line Anterior to the vertebral column, poster
ior to the sternum
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The Heart Anatomy
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Coverings of the Heart Pericardium
a double-walled sac around the heart
composed of A superficial fibrous pericardium
A deep two-layer serous pericardium The
lines the internal surface of the fibrous
pericardium The or epicardium lines the sur
face of the heart They are separated by the flu
id-filled pericardial cavity
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Pericardial Layers of the Heart
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Heart Wall
visceral layer of the serous pericardium
cardiac muscle layer forming the bulk of th
e heart Fibrous skeleton of the heart crisscr
ossing, interlacing layer of connective tissue
endothelial layer of the inner myocardial s
urface
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External Heart Major Vessels of the Heart
(Anterior View
Vessels to the heart include
Superior and inferior venae cavae Right and
left pulmonary veins Vessels away from the
heart include Pulmonary trunk, which splits i
nto right and left pulmonary arteries
Ascending aorta (three branches) brachioceph
alic, left common carotid, and subclavian
arteries
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External Heart Vessels that Supply/Drain
the Heart
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External Heart Vessels that Supply/Drain
the Heart ( Posterior View)
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Atria of the Heart
Atria are the chambers of the heart
Each atrium has a protruding Pectinate muscle
s mark 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 chambers of the heart
muscles mark ventricular walls Right vent
ricle pumps blood into the pulmonary trunk
Left ventricle pumps blood into the aorta
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Gross Anatomy of the Heart
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Pathway of Blood through the Heart and Lungs
Right atrium ? tricuspid valve ? right ventricle
Right ventricle ? pulmonary semilunar valve ? pu
lmonary arteries ? lungs Lungs ? pulmonary vein
s ? left atrium Left atrium ? bicuspid valve ?
left ventricle Left ventricle ? aortic semiluna
r valve ? aorta Aorta ? systemic circulation
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Pathway of Blood through the Heart and Lungs
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Coronary Circulation
Coronary circulation is the supply to the
heart muscle itself Collateral routes ensure bl
ood delivery to heart even if major vessels are
occluded
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Heart Valves
Heart valves ensure 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 valve lies between the left ventricle
and the aorta valve lies between the right
ventricle and pulmonary trunk Semilunar valves
prevent backflow of blood into the ventricles
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Heart Valves
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Heart Valves
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Atrioventricular Valve Function
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Semilunar Valve Function
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Heart Sounds
Heart sounds (lub-dup) are associated with
closing of heart valves First sound occurs as A
V valves close and signifies beginning of
systole Second sound occurs when SL valves clos
e at the beginning of ventricular diastole
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Cardiac Cycle
Isovolumetric relaxation early diastole
Ventricles relax Backflow of blood in aorta
and pulmonary trunk closes semilunar valves
Dicrotic notch brief rise in aortic pressure c
aused by backflow of blood rebounding off
semilunar valves
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Other features of the heart
The a specialized bundle of neurons in
the upper corner of the right atrium. They act
as the hearts natural pacemaker. Impulses genera
ted in the SA node cause an electrical cascade
resulting in the beating of the heart
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Other features of the heart
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Other features of the heart
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Other features of the heart
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Other features of the heart