ANP 1105 Lecture Notes - Lecture 8: Vasomotor Center, Blood Vessel, Vasomotor

• School: University of Ottawa
• Department: Anatomy and Physiology
• Course: ANP 1105
• Professor: William Staines

Document Summary

Capillaries are fragile so high pressure would rupture them. Most capillaries are extremely permeable; lots of exchange at low bp. Muscular pump (skeletal muscles, contraction/relaxation it pushes blood through the veins, one-way flow) Homeostatic mechanisms in place to maintain adequate flow to tissues under a variety of circumstances. Cardiac output (co) [heart rate x stroke volume: hr (neural and hormonal factors, sv (venous return, neural and hormonal factors) Peripheral resistance [diameter of vessels, blood viscosity, vessel length] Alter blood distribution to respond to specific demands. Maintain adequate map (mean arterial pressure) by altering blood vessel diameter. Cluster of sympathetically neurons in medulla (part of the cardiovascular center) Vasomotor tone is the constant input, especially to arterioles (ne) Any increase in sympathetic nervous system activity generalized vasoconstriction and rise in blood pressure; decrease have a reverse effect. Vasomotor center responds to baroreceptors, chemoreceptors, higher brain centers or hormones: baroreceptors. Receptors that sense changes in pressure in the walls of the arties.