BIOL 205 Lecture Notes - Lecture 17: Blood Pressure, Blood Vessel, Hemoglobin
Document Summary
Functions of circulatory system: bulk transport of materials (e. g. pick up nutrients form digestive system; gas exchange; waste eliminating, messenger carrier (e. g. hormones and regulators, distributing, exchanging and dissipating heat. Immune functions (e. g. carries antibodies: also the target of antigens, and will spread cancer cells. Circulatory system: absent in simple animals such hydra, which can complete material and gas exchange through simple diffusion. No circulatory system; interstitial fluid is moved by muscle contraction. Material exchange is accomplished by diffusion or transport: some fish have accessory caudal heart, the separation between deoxygenated and oxygenated blood is more complete in animals such as mammals, birds, and reptiles, than frogs. 0. 98: slight decrease in heart size with increase body size in birds. Some small animals (e. g. shrews) are exceptions to these rules, to compensate its high metabolic rate. Thicker blood, relatively larger heart, faster heart rate (probably the maximum for all organisms due to limit in muscle contraction)
