Local Control Of Blood Flow Part 1 Flashcards
Since all organs of systemic circulation are exposed to the _____ perfusion pressure, the differences in blood flow to the various vascular resistance
Same
Vascular resistance of an organ is determined mainly by the ______ of its _______
Diameter
Arterioles
When sphincters open- blood flows through _____ capillaries
True
When sphincters close- blood flows through __________ thoroughfare channel and bypasses true capillaries
Metarteriole
What acts within an organ or tissue and do NOT rely on the external influence?
Intrinsic mechanism
What acts from outside an organ or tissue through nerves or hormones, to alter arteriolar resistance?
Extrinsic mechanism
What mechanisms predominate in controlling the arteriolar resistance of the organs that can withstand temporary blood flow reductions?
Extrinsic
What muscles can withstand temporary blood flow reductions?
Kidneys, splanchnic organs, resting skeletal muscles
What mechanisms has the purpose to make extra blood available for the critical organs?
Extrinsic
What mechanisms control arteriolar resistance predominate in critical organs?
Intrinsic
What are the critical organs that are controlled by intrinsic mechanisms?
Brain, hear, working skeletal muscles
What is an example of an intrinsic mechanism that is the following:
Released from mast cells
Acts locally on arteriolar smooth muscle to relax it
Increases blood flow to tissue
Paracrine
Histamine
Histamine is Paracrine meaning:
Signaling moves by ________ and only effective over very _____ distances
Diffusion
Short
Exercise that increases metabolic rate in skeletal muscles is an example of what type of mechanism?
Intrinsic
Metabolic control is a local mechanism that matches tissue blood flow to its _________ ____
Metabolic rate
