BIOL 204 Lecture Notes - Lecture 13: Blood Plasma, Fibrin, Bone Marrow
Document Summary
Four general types of circulatory systems: diffusion exchange, animals with very small body size (and therefore, high sa:volume ratios) don"t need a specialized circulatory or gas exchange system. Organization of vertebrate circulatory systems: heart arteries (thicker than veins) arterioles capillaries & capillary beds venules veins (same structure as arteries, but thinner) back to heart. Artery structure: outer layer, connective tissue, smooth muscle, endothelium) Capillary structure: outer layer (basal lamina), endothellium: 2 chambered heart: atrium and ventricle / single circulation (ex. fish, 3 chambered heart: left & right atrium and single ventricle\ / double circulation (ex. amphibians) 90% of o2-rich blood sent to systemic circuit (carries blood away from heart and delivers to most organs and tissues) 90 % of o2-poor blood sent to pulmocutaneous circuit (conducts blood only between heart and lungs) Left side only receives & pumps o2 rich blood. Right side only does o2 poor blood. Birds and mammals cannot reduce blood flow to lungs like amphibians.
