Chapter 21: Blood Vessels and Circulation Flashcards
the layer of vascular tissue that consists of an endothelial lining and an underlying layer of connective tissue dominated by elastic fibers is the…
tunica intima
smooth muscle fibers in arteries and veins are found in the…
tunica media
one of the major characteristics of the arteries supplying peripheral tissues is that they are…
muscular
the only blood vessels whose walls permit exchange between the blood and the surrounding interstital fluids are…
capillaries
one of the primary characteristics of continous capillaries is that they prevent…
the loss of blood cells and plasma proteins
the unidirectional flow of blood in venules and medium sized veins is maintained by…
the presence of valves
the specialized arteries that are able to tolerate the pressure shock produced each time ventricular systole occurs and blood leaves the heart are…
elastic arteries
where does the greatest drop in blood pressure occur?
arterioles
if the systolic pressure is 120 mm Hg and the diastolic pressure is 90 mm Hg, the mean arterial pressure(MAP) is…
100 mm Hg
the distinctive sounds of Korotkoff heard when taking the blood pressure are produced by…
turbulences as blood flows past the constricted portion of the artery
the phenomenon that helps maintain blood flow along the arterial network while the left ventricle is in diastole is…
elastic rebound
the most important factor in vascular resistance is…
friction between blood and the vessel walls
two factors that assist the low venous pressures in propelling blood toward the heart are…
elastic rebound and mean arterial pressure
what correctly identifies all the factors that would increase blood pressure?
increasing CO, decreasing SV, increasing VR, decreasing PR, increasing BV
the two major factors affecting blood flow rates are…
pressure and resistance
for circulation to occur, the circulatory pressure must be sufficient to overcome the…
total peripheral resistance
atrial natriuretic peptide (ANP) reduces blood volume and pressure by…
- blocking release of ADH
- stimulating peripheral vasodiliation
- increased water loss through the kidneys
the circulatory regulatory mechanisms that can assist in short term and long term adjustments…
endocrine responses
the regulatory mechanism that cause immediate, localized homeostatic adjustments is…
autoregulation
the central regulation of cardiac output primarily involves the activities of the…
autonomic nervous system
an increase in cardiac output normally occurs during…
widespread sympathetic stimulation
stimulation of the vasomotor center in the medulla causes __________, and inhibition of the vasomotor center causes __________.
vasoconstriction; vasodilation
hormonal regulation by ADH, epinephrine, angiotensin II, and norepinephrine results in…
increasing peripheral vasoconstriction
the three primary interrelated changes that occur as exercise begins are…
increasing vasodilation, increasing venous return, and increasing cardiac output
