PHYL2001 Lecture Notes - Lecture 6: Sympathetic Nervous System, Central Venous Pressure, Skeletal Muscle
Document Summary
Elastic and connective tissue contains the pressure. Flow (q") depends on a pressure difference. Flow also depends on the resistance of the vessel. Small vessels have more resistance than large vessels: Increase in peripheral resistance increase in mean arterial pressure. Increase in cardiac output increase in mean arterial pressure. Increase in heart rate increase in cardiac output. Increase in stroke volume increase in cardiac output. Most of the resistance to blood flow is in arterioles. Lots of smooth muscle in arterioles allows control of diameter and resistance. Control where the blood flows to: distribution of cardiac output. Decrease in sympathetic tone decrease in resistance. Decrease in global sympathetic tone decrease in total peripheral resistance decrease in arterial blood pressure. Decrease local sympathetic tone decrease resistance increase in blood flow. As a group arterioles alter total peripheral resistance and mean blood pressure. In a vascular bed they control the flow. Capacitance (compliance): volume is greatest in the venous system.
