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Details Title: Anatomy Description: Regulation of blood flow Total Flash Cards: 14 Created: 02/16/2004 15:06:11	To study from this set of flash cards, or to create your own your own study flash cards, register HERE. If you are already a registered user, CLICK HERE.
Cards Term what is the goal to regulate blood flow? Definition to maintain homeostasis in blood flow to tissues-not too much, not too little requires constant adjustments in blood pressure(usually accompanied or accomplished by changes in resistance & changes in blood volume) Term what's autoregulation? Definition changes in local tissue environment cause changes in blood flow to that region via precapillary sphincters ex: O2 levels fall & CO2 levels rise in active muscles, cause sphincter to open & more blood flows through capillary bed Term what is the regulation at the tissue(capillary bed) level? Definition autoregulation Term what else does autoregulation assume? Definition there is adequate blood flowing to the capillary bed, systemic blood pressure must be maintained via short-term & long-term mechanisms Term systemic BP maintained(short-term mechanisms) by Definition baroreceptors Term what are baroreceptors? Definition pressure sensors in carotid artery signal brainstem, which relays signal via autonomic nervous system to change heart rate & artery diameter; good for minute-to-minute control, but can adapt(like touch receptors) to high BP Term what's an example of baroreceptors? Definition systemic flow to brain decreases as you stand up; baroreceptors signal brainstem, sympathetic nervous system increases heart rate & contractility, & causes peripheral vasoconstriction=results in inc of blood flow to brain Term what are venules? Definition have no smooth muscle; "leaky" site of fluid & WBC release into tissue Term what are veins? Definition very little elastin(pressure is low) or smooth muscle(no active vasoconstriction) backflow prevented by: valves & skeletal muscle contraction Term what causes varicose veins? Definition valves leak, pooling of blood causes walls to weaken & dilate Term adequate blood supply or flow is needed in? Definition tissues Term blood flow=? Definition difference in pressure/resistance Term what's difference in pressure? Definition blood pressure-blood flows from high pressure to low pressure Term what's resistance? Definition force that opposes the movement of blood -plaque build up -high red blood cell count -turbulence(not flowing way should, murmur)