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
|
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
|
|
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
|
|
Term
|
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
|
Definition
| have no smooth muscle; "leaky" site of fluid & WBC release into tissue |
|
|
Term
|
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
|
|
Term
|
Definition
| difference in pressure/resistance |
|
|
Term
| what's difference in pressure? |
|
Definition
| blood pressure-blood flows from high pressure to low pressure |
|
|
Term
|
Definition
force that opposes the movement of blood
-plaque build up
-high red blood cell count
-turbulence(not flowing way should, murmur) |
|
|
