BIOL 1002 Chapter : CH 32 NOTES
Document Summary
The circulatory system transports food and oxygen close to each cell and carries away wastes produced by the cells. Three major parts: heart- a pump that keeps blood circulating, blood- a liquid that serves as medium of transport, blood vessels- a system of tubes that conducts blood throughout the body. Consists of muscular chambers capable of strong contractions: Atria (collects blood, contractions send blood to ventricles) Ventricles (contractions circulate blood through lungs and to the rest of the body) Cardiac muscle cells- small, branched and packed with orderly array of protein strands which give striped appearance. Caused by coordinated contractions of atrium and ventricle. Cardiac cycle: 2 atria contact in synchrony, emptying contents to ventricles, 2 ventricles contract in synchrony, forcing blood into arteries, both atria and ventricles relax briefly, cycle begins again. Cycle occurs in under 1 second (70 times per minute) in a resting person. Electrical impulses coordinate the sequence of heart chamber contractions.
