BIOL 206 Lecture Notes - Lecture 23: Parapodium, Pipette, Countercurrent Exchange
Document Summary
Animals: not all animals pump blood under high pressure, grasshoppers have open circulatory system. There is pumping tubular hearts, but they have ostia (opening). Pump fluid that serves as blood and tissue fluid. Need that to continue circulating to promote diffusion. Partly because open circulatory systems are not very efficient: grasshopper still have very active lifestyle, earthworm has a closed circulatory system. Combined with muscular body movements, helps circulate blood. Gas exchange organ is integuments/ small capillaries: several different pigments in blood. Ex: crabs have copper based pigment so they have blue blood: can you pump under pressure and keep that for flow rate. Can you direct circulation for body parts that need it a time: veins look blue because blood contains collagen. It is not actually colored blue: low pressure circulation may favor alternative methods of gas exchange, each cell has a near direct means of fas exchange via tracheal systems.
