BIOL 1201 Chapter : 17 From Gene To Protein Copy
Document Summary
Concept 42. 1: circulatory systems link exchange surfaces with cells throughout the body: transport systems functionally connect the organs of exchange with the body cells, gastrovascular cavitites, hydras, jellies, and other cnidarians lack a distinct circulatory system. One or more hearts pump blood into large vessels that branch into smaller ones that infiltrate the organs. Within organs, arteries branch into arterioles (small vessels that convey blood to the capillaries): capillaries = microscopic vessels with very thin, porous walls. The blood passes through the heart once in each complete circuit. Blood entering the heart collects in the atrium before transfer to the ventricle. Contraction of the ventricle pumps blood to the gills, where there is a net diffusion of o2 into the blood and of co2 out of the blood. As blood leaves the gills, the capillaries converge into a vessel that carries oxygen-rich blood to capillary beds throughout the body.
