HSCI 100 Lecture Notes - Lecture 7: Heart Valve, Varicose Veins, Lymphatic Vessel

• School: Simon Fraser University
• Department: Health Sciences
• Course: HSCI 100
• Professor: Mark Lechner

Document Summary

Includes the heart and blood vessels: blood is refreshed in the lung, kidneys, intestine and liver, lymphatic vessels help this system by collecting excess uid surrounding tissues and. Functions: transport blood, exchange of nutrients (e. g. glucose) and wastes (e. g, exchange of nutrients (e. g. glucose) and wastes (e. g. co2) at the capillaries, regulate blood ow/pressure as needed! Heart arteries arterioles capillaries venules veins back to the heart : arteries and arterioles! Outer connective tissue not as thick as arteries/arterioles! Lower pressure, larger volume than artery system! How does the heartbeat occur: during systole the atria contract together followed by the ventricles contracting together, this is followed by diastole, a rest phase, when the chambers relax, this cardiac cycle = heartbeat. On average, it occurs 70 times/minute (one beat / 0. 85. How is the heartbeat controlled: internal control:! The sinoatrial (sa) node in the right atrium initiates the heartbeat and causes ! the atria to contract!