BIO 203 Lecture Notes - Lecture 15: Purkinje Fibers, Systolic Geometry, Vasoconstriction
17 Dec 2016
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Document Summary
In very small organisms, vital substances are exchanged through diffusion (oxygen) Circulatory systems move fluid from the surface of an organism to its deepest parts in larger animals. Two important parts: a space for fluid to move in (open cavity with fluid moving around, pumping mechanism to distribute fluid (heart) Cardiovascular systems are a subtype composed of heart, blood, and blood vessels. A pressure gradient causes a liquid or gas to move from one compartment to another, if there is a path for movement. Works for mixtures of substances in a fluid: examples: blood, air in lungs, stomach contents, urine (not a concentration gradient) Top 5 traits that helps animals pass. Arose in the ancestor to all triploblasts (animals that have 3 tissue layers) Allowed animals to become much larger since diffusion wasn"t limiting exchange. Circulatory fluid: one fluid- hemolymph= interstitial fluid, 2 fluids- blood and lymph. O2 and co2 are carried by molecules called respiratory pigments.
