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What are trebeculae carnae?
Muscle bundles in the interventricular septum of the heart. Helps the ventricles with contraction by becoming stiff to form a fixed fulcrum for the ventricles to contract against.
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What are the great vessels of the heart and their purpose?
Inferior and superior vena cavas, pulmonary vein and artery, and aorta. The purpose of the great vessels is to connect the heart to the systemic and pulmonary circulation.
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What are the branches of the aorta?
Brachiocephalic trunk (innominate artery), left common carotid artery, and left subclavian artery.
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Describe the type, structure, and number of heart valves.
AV valves: located on each side of heart between the artrium and ventricle. Controlled by the chordae tentinae (thin strands of fibrous tissue) to open and close the valve cusps. The right side one is call tricuspid (3 cusps) and the left side one is called bicuspid or mitral valve (2 cusps).
Semilunar valves: Located on the mouth of the aorta and pulmonary vein. These valves are secured by a fibrous ring, but no muscle control the opening of the cusps. Each of the valves have only two semilunar shapped valves.
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What are the layers of the heart?
The heart has three layers: Epicardium, myocardium, and Endocardium.
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What main vessels are involved in the coronary circulation?
The vessels that supply the blood are:LAD, LX, right coronary artery and great cardiac vein that empties into the coronary sinus that in turn empties into the right atrium.
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(a)What is the purpose of the caridac cycle?
The cardiac cycle is the process that re-oxygenates the body's blood.
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What is cardiac output (CO)?
Volume of blood pumped out of the left ventricle into the aorta in 1 min.
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What is stroke volume (SV)?
Volume of blood ejected by the left ventricle in 1 min.
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What three factors does stroke volume depend on. Describe each.
- The three factors:
- a. Preload contractility - Tension in the heart created by blood backup in atrium.
- b. Afterload contractility - tension in the arteries.
- c. Myocardial contractility - Tension developed within cardiac muscles of the heart.
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What is the differnce between low and high cardiac output failures?
Low cardiac output failures when the CO falls below normal and cannot meet the need of the body.
High cardiac output failure occurs when the CO is above normal but stiil can meet the demands of the body.
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