Chapter 18 The Heart Flashcards
The heart is approximately the size of your
fist
The heart is at the superior surface of the
diaphragm
The heart is left of the
midline
The hear is anterior to the
vertebral column, posterior to the sternum
Heart Anatomy
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Pericardium
a double-wall sac around the heart
The pericardium is a superficial
fibrous pericardium
the pericardium is a deep two-layer
serous pericardium
The deep two-layer pericardium
- the parietal layer lines the internal surface of the fibrous pericardium
- the visceral layer or epicardium lines the surface of the heart
- these two layers are separated by the fluid-filled pericardial cavity
The perocardium
- protects and anchors the heart
- prevents overfilling of the heart with blood
- allows for the heart to work in a relatively friction-free environment
Pericardial Layers of the Heart
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The heart wall is made up of the
epicardium, myocardium, fibrous skeleton, and endocardium
epicardium
visceral layer of the serous pericardium
myocardium
cardiac muscle layer forming the bulk of the heart
fibrous skeleton of the heart
crisscrossing, interlacing layer of connective tissue
endocardium
the endothelial layer of the inner myocardial surface
Cardiac muscle bundles
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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
External Heart: Major Vessels of the Heart)Anterior View)
Vessels conveying blood away from the heart:
- Pulmonary trunk, which splits into right and left pulmonary arteries
- Ascending aorta (three branches)-brachiocephalic, left common carotid, and subclavian arteries
External Heart: Vessels that Supply/Drain the Heart (Anterior View)
Arteries:
right and left coronary (in an atrioventricular groove), marginal, circumflex, and anterior interventricular arteries
External Heart: Vessels that Supply/Drain the Heart (Anterior View)
Veins:
small cardiac, anterior cardiac and great cardiac veins
Picture of the Heart (anterior view)
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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
External Heart: Major Vessels of the Heart (Posterior View)
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 an atrioventricular groove) and the posterior interventricular artery (an interventricular groove)
External Heart: Vessels that Supply/Drian the Heart (Posterior View)
Veins:
great cardiac vein, posterior vein to the left ventricle, coronary shuns, and middle cardiac vein
Picture of the Heart (Posterior View)
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Picture of the Heart (inside view)
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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
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
Right and left ventricles
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Pathway of Blood through the heart
- right atrium-> tricuspid valve->
- right ventricle-> pulmonary semilunar vavle->
right ventricle
pulmonary arteries-> lungs
Pathway of Blood through the lungs
- Lungs-> pulmonary veins->
- Left atrium-> bicuspid valve->
- Left ventricle-> aortic semilunar valve->
- Aorta->
left atrium
left ventricle
aorta
systemic circulation
Systemic Circuit
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Heart Valves
Aortic semilunar valve lies between the
left ventricle and the aorta
Heart Valves
Pulmonary semilunar valve lies between the
right ventricle and pulmonary trunk
Heart Valves
Semilunar valves
prevent backflow of blood into the ventricles
Electrocardiography
Electrical activity is recorded by
electrocardiogram (ECG)
Electrocardiography
P wave corresponds to
depolarization of SA node
Electrocardiography
QRS complex corresponds to
ventricular depolarization
Electrocardiography
T wave corresponds to
ventricular repolarization
Electrocardiography
Atrial repolarization record is masked by
the larger QRS complex
Heart sounds (lub-dup) are associated with
closing of heart valves
Heart Sounds
First sound occurs as AV valves close and
signifies the beginning of systole
Heart Sounds
Second sound occurs when SL valves close at the
beginning of ventricular diastole
The cardiac cycle refers to all events associated with
blood flow through the heart
Systole
contraction of the heart muscle
Diastole
relaxation of the heart muscle