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Unformatted text preview: thers taking nutr ients so not sufficient b/c dr iving force is not ver y large deliver y of nutr ients thus keeping diffusion ratings relatively high c production in blood Hb blood car r ying capacity rest oration of O2 deliver y Biology 2A03 L7 Lecture 7 Circulation I 1. Sample questions found on lecture slides The Circulation 1. Why have a circulatory system? 1. Diffusion times (t) are proportional to the distance (x) 2 over which diffusion occurs 1. Larger the distance that diffusion is occurring at, the greater the time needed diffusion not quick enough 1. Diffusion gradients for nutrients or wastes can decrease over large distances 1. Need a concentrat ion gradient for diffusion greater the gradient = greater flux rate 1. 1. Driving force for waste removal is different between waste out and nutrients in 2. Gradient maintained high Biology 2A03 L7 3. Very small distance for diffusion so sufficient Circulatory Systems 1. fast connection system = rapidly circulating fluids between surfaces that equilibrate external mileau and cells deep inside organisms 1. 1 role = dist ribut ion of dissolved gases and molecules for nut rit ion growth and repair 2ary role = 1) fast chemical signaling 2) dissipating heat 3) inflammatory and host defences against microorganisms 1. System consists of: 1) A connective medium = blood (communication system connects different areas of body; e.g. chemical messengers 2) Plumbing = blood vessels (regulates blood pressure and blood distribution) 3) A pump = heart (sensory and endocrine functions releases hormones) The Circulatory System 1. Composed of 2 circuits: 1) Pulmonary circulation 1. Picks up O 2 in lungs 2. Low pressure system (20mmHg) 3. Right ventricle lungs left atrium 2) Systematic circulation 1. Delivers O 2 to organs and tissues (except lungs) Biology 2A03 L7...
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