Homeostasis- regulation of the bodys internal environment Flashcards
what is the homeostatic mechanism
external environment changes largely over time, internal environment has small changes over time
homeostasis regulates
a physiological variable relative to a set point or a set range
what things may homeostasis involve to maintain itself
-negative feedback
-positive feedback
-feedforward
in most complex regulation, all three may be used
what is negative feed back
-body temperature regulation in endothermic animals
-endotherm vs ectotherm
-homeotherm vs heterotherm
-hermogenesis
how do endotherms generate heat
internally
birds and mammals—keep their bodies at an optimal temperature by regulating two processes: (1) the amount of heat generated by internal oxidative reactions and (2) the amount of heat exchanged with the environment.
how do ectotherms generate heat
ectotherms fluctuate with environmental temperatures, and ectotherms are typically less active when it is cold.
what are homotherms
maintain body temperature at a set range
what are heterotherms
varies their body temp depending on what external environment is doing
what is thermogenesis
The generation of heat by oxidative mechanisms in nonmuscle tissue throughout the body is termed non-shivering thermogenesis. In the young of many mammals, the most intense heat generation is by nonshivering thermogenesis that takes place in a specialized brown adipose tissue (also called brown fat), which can produce heat rapidly.
what are the two ways hypothalamic centres can be triggered
-change in skin temp which triggers peripheral thermoreceptors in the skin
-change in core temperature which triggers central thermoreceptors in hypothalamus, abdomen organs, and elsewhere
what is the hypothalamic centre
-its for the thermalregulation (bodys thermostat)
-organ to make comparison
how much change can the hypothalamic centre sense
0.01 deg Celsius cange in temp
what are some things the the sympathetic nervous system can do to regulate body temp
-smooth muscle in arteriole in skin (vasodilation and constriction, adjustments in the loss or conservation of heat in the skin)
-sweat glands (sweating, adjustment in heat loss)
-smooth muscle in the skin (piloerection, adjustment in conservation or loss of heat)
what are some things that the motor neurons can do to regulate body temp
-skeletal muscles (muscle tone, shivering, adjustments in muscle activity (in metabolic output))
what is negative feed back
returns variable to set point
i.e minimizes difference between actual level and set point
