PNB 2250 Chapter Notes - Chapter 10: Cardiac Output, Invertebrate, Smooth Muscle Tissue
29 Sep 2016
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Document Summary
Understand the structure & function of the vertebrate heart. Understand structure & function of the invertebrate heart. Understand structure & function of blood vessels & blood flow. Advantages: different paths for blood, different pressures for blood, two hearts in parallel, hearts must pump same volume of blood, huge advantage in terms of size. Disadvantages: complex, hard to regulate, high blood pressures. Evolutionary changes: simple contraction to chambered pump, chambers. Better control of pressure & flow: parallel chambers. Heart size (4-chambered: output need, heart size increases with body size (proportionately the same volume) About 6% of body mass: irrespective of metabolism, changeable rates satisfy metabolic needs. Physiological implications: physical limit on heart size. Many other things in the same area: constraint not due to metabolic needs. Due to space issues: overcome limitations by altering rate/volume (output) Output of the pump can be varied.
