Local control of blood flow
autoregulation
- myogenic mechanism
- inherent behaviour of smooth muscle
- stretch induces depolarisation = smooth muscle contraction
- gets overriden by metabolic effect and hyperaemia
- "metabolic theory": local vasodilators get washed out by ↑ blood flow
metabolic
- K+ → vasodilation
- Hypoxia → ↓ ATP → K+ channels activate = hyperpolarisation
- CO2, acidosis → ↑ NO2 production, inhibition of Ca entry to smooth muscle
- Adenosine