Chapter 40 Concept 40 1 Animal form and funtion are correlated at all levels or organization In vertebrates the space between cells is filled with interstitial fluid which allows movement of material in and out of cells Complex body plan helps an animal living in a variable environment maintain homeostasis Concept 40 2 Feed back control maintains the internal environment in many animals Regulating and conforming Regulator uses internal control mechanisms to moderate internal change in the face of external environmental fluctuation Conformer allows internal conditions to vary with certain external changes Homeostasis Homeostasis main safe state Mechanisms of homeostasis Given variable fluctuations above or below a set point serve as a stimulus these are detected by a sensor and trigger a response Feedback control in homeostasis Dynamic equilibrium of homeostasis is maintained by a negative feedback which helps to return from a variable to a normal range Concept 40 3 Homeostasis processes for thermoregulation involve form function and behavior thermoregulation process by which animals maintain an internal temp with in a tolerable range Endothermic generate own body heat Ectothermic absorb heat from outside Balancing heat loss and gain 1 Radiation Transfer of heat between objects not in direct contact 2 Evaporation removal of heat from surfaces as liquid evaporates 3 convection transfer of heat as air or liquid moves past surface 4 conduction direct transfer of heat 5 adaptions help animals thermoregulation 1 Insulation 2 Circulatory Adaptions regulation of blood flow near the body surface vasodilation blood flow in skin increases facilitating heat loss vasoconstriction blood flow in skin decreases lowering heat loss Countercurrent Exchange transfer heat between fluids flowing in opposite directions and reduce heat loss used by marine animals 3 cooling by evaporative heat loss 4 Behavioral responses 5 Adjusting metabolic heat production thermogenesis adjustment to metabolic heat production to maintain body temp Increased by muscle activity such as moving or shivering Physiological Thermostat and Fever thermoregulation is controlled by a region of the brain called hypothalamus Triggers heat loss or gain Fever is result of a change to the set point for a bio thermostat
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