Local Regulation of Blood Flow

Local Regulation of Blood Flow

• autoregulation - most important in kidney, heart, and brain (not in lung)
• MECHANISM = matching R and P to keep Q constant  
• Q = P/R
• myogenic reflex  (stretch activated channels if P is high; K channel activation if P is low)
• range over which autoregulation occurs may change;e.g., chronic hypertension shifts range to higher values.

• metabolic regulation

• In Lungs hypoxia has opposite effect = vasoconstriction - mediated by specializes K channels that are inhibited by hypoxia = depolarization and Ca influx.

• Flow regulation
• hemodynamic forces