Chapter 6 - Circulatory System Vocabulary Flashcards
(172 cards)
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The pressure in the aorta against which the left ventricle must pump blood
Absolute refractory period
The early phases of repolarization in which the cell contains such a large concentration of ions that it cannot be stimulated to depolarize
Agranulocytes
Leukocytes that lack granules
Albumins
The smallest of plasma proteins; they make up about 60% of these proteins by weight
Alpha effect
Stimulation of alpha receptors that result in vasoconstriction
Anemia
A lower than normal hemoglobin or erythrocyte level
Anterior descending (LAD) coronary artery
One of the two branches of the left main coronary artery
Anti-bodies
Proteins secreted by certain immune cells that react against foreign antigens in the body by binding to the antigens, making them more visible to the immune system
Antigens
Substances or molecules that, when taken into the body, stimulate immune system response and cause formation of specific protective proteins called anti-bodies
Aorta
The principal artery leaving the left side of the heart and caring freshly oxygenated blood to the body; the largest artery in the body
Aortic arch
One of the three described portions of the aorta; the secretion of the aorta between ascending and descending portions that gives rise to the right brachiocephalic (innominate), left common carotid, and left subclavian artery
Aortic valve
The semi lunar valve that regulates blood flow from the left ventricle to the aorta
Arteries
The muscular, thick walled blood vessels that carry blood away from the heart
Arterioles
Subdivisions of arteries that are thinner and have muscles in their walls that are innervated by the sympathetic nervous system
Arteriosclerosis
A pathologic condition in which the arterial walls become thickened and inelastic
Ascending aorta
The first of three portions of the aorta; originates from the left ventricle and gives rise to two branches, the right and left main coronary artery
Atherosclerosis
A disorder characterized by the formation of plaques of material, mostly lipids and cholesterol, on the inner arterial walls
Atria
The upper chambers of the heart; they receive blood returning to the heart
Atrioventricular (AV) node
A specialized structure located in the AV junction that slows conduction through the AV junction
Atrioventricular valves
the mitral and tricuspid valve through which blood flows from the atria to the ventricles
Automaticity
A state in which the cardiac cells are at rest, waiting for the generation of a spontaneous impulse from within
Axillary vein
The vein that is formed from the combination of the basilisc and cephalic vein; it drains into the subclavian vein
B cells
Lymphocytes that produce and secrete antibodies that bind and destroy foreign antigens
Baroreceptors
Receptors in the blood vessels, kidneys, brain, and heart that respond to changes in pressure in the heart or main arteries to help maintain homeostasis