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16 Cards in this Set
- Front
- Back
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QRS complex |
Ventricular depolarization (hidden atria depolarization) |
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P wave |
Atrial depolarization; atrial contraction |
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T wave |
Ventricular depolarization |
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Systole |
Contraction of heart |
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Diastole |
Relaxation of heart |
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EDV (end diastolic volume) |
Amount of blood in the ventricles when the heart is relaxed. |
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EDV (End systolic volume) |
The amount of blood left in the ventricles when the heart is contracted. |
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SV (Stroke volume) |
Volume of blood ejected by each ventricle during a single contraction. |
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HR (Heart rate) |
Number of heartbeats per minute. |
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CO (cardiac output) |
The volume of blood pumped out of the right or left ventricle per minute.
CO= SV x HR |
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What regulates SV? |
Preload: the degree to which cardiac muscle cells are stretched by blood entering the heart. *the greater the heart is stretched, the greater the contraction force*
Contractility: degree to which cardiac muscle cells contract as a result of extrinsic factors. There are positive (increase contractility) and negative (decrease contractility) inotropic factors.
Afterload: Measure of the pressure that must be generated by the ventricles to force the semilunar valves open. (Greater after load = smaller SV)
*arteriosclerosis and high BP increase after load and reduce SV* |
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What regulates HR? |
Autonomic nervous system via the parasympathetic and sympathetic nervous systems
Chemicals: hormones and ions. Epinephrine and thyroxin increase HR. |
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What are the layers of blood vessels? |
Tunica intima: inner layer. Composed of endothelium (simple squamous) surrounded by connective tissue.
Tunica media: middle layer. Composed of smooth muscle with variable elastic fibers.
Tunica adventitia: outer layer, composed of connective tissue. |
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What artists branch off of the Aorta? |
Brachiocephalic which further branches into the right common carotid and right subclavian arteries.
Left common carotid
Left subclavian |
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What are he formed elements of the blood? |
Erythrocytes: red blood cells Leukocytes: white blood cells Platelets: clotting proteins |
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How is oxygen transported in the blood? |
Via red blood cells. Oxygen binds to hemoglobin as oxyhemoglobin (HbO2). |
