Explain how blood flow through tissues is regulated in gener

Explain how blood flow through tissues is regulated in general, and in skeletal muscle and the brain.

Solution

Answer

Blood flow regulation in tissues & skeletal muscle & brain =

intrinsic mechanism

1] Vasodilator mechanism= insufficient blood flow to tissues results in build of vasodilatory substances that locally diffuse & induce vasodilation of adjacent arterioles & precapillry sphincters

Lactic acid , adenosine ,CO2 , hydrogen ions ,& potassium ions display property of vasodilator substances

resulting in increase in blood flow to the tissues

When blood flow is excessive ,the baseline concentrations of these substances decreases ,resulting in vasoconstriction of arterioles & precapillary sphincters

2] Oxygen deficiency mechanism=Vascular smooth muscle cell requires sufficient oxygen & nutrients to mentain tension

In absence of sufficient O2 & nutrients vascular smooth muscle cells will naturally relax ,causing vasodilation of arterioles & precapillary sphincters

3] Myogenic mechanism=

4] Brain = cerebral blood flow is much more sensitive to changes in CO2 & hydrogen ions than other metabolites likely because neuronal function is highly sensitive to changes in PH which are determined by the balance between local CO2 & H+ ions concentrations