Blood Flow Regulation Review Flashcards
Diffusion and distance
Distance dramatically delays the diffusion
LT vs. ST control
ST - rapid changes in vasodilation/vasoconstriction of arterioles
LET - slow controlled changes of days, weeks, mos…provide even better control of flow…result of increase or decrease in the physical size and #s of actual blood vessels supplying the tissues
Vascular remodeling
Can change both diameter and cross-sectional number
Angiogenesis
Growth of new BVs - important natural process occurring in the body, both in health and dz
Occurs in healthy body for healing wounds and for restoring blood flow to tissues after injury or insult
In females, during monthly reproductive cycle and dudring prefg
Blood reservoiur
Venous system
More than 60% of all blood in circulatory system is in the veins
Vascular compliance
Inc in volume/Inc in pressure
Veins more compliant due to structure…means can store more blood
Veins vs. arteries
Larger lumen
Thinner msooth muscle
Thicker adventitia
Symp regulation of venous return
Walls of veins contain smooth muscle innervte
Stimulation leads to NE release which contracts and dec diameter and compliance and therefore increasing pressure
Varicose veins
Valves of venous system are incompetent
When pt stands, cap HS pressure inc…filtration of plasma to interstitial…edema…inadequate diffusion of nutritional material…muscle pain and wekaness
POsture and pressure diff
Most when walking because skeletal muscle will contract and pump blood back to the heart
Resp pump
During inspiration, diaphragm descends, inc abdominal pressure nad inc intraabdominal vein pressure
At same time, pressure in the intrathroacic veins and right atrium is dec
Net effect is increase in pressure diff between peripheral veins and the heart and enhanced venous return
Respiration would reverse htis effect if not for venous valves
