UNIT 4: Homeostasis
Chapter 9: Homeostasis: A Fine Balance
pg. 426 -
9.3: Thermoregulation
pg. 436 - 441
Temperature Regulation: A Built-in Thermostat
Thermoregulation – is the regulation of internal temperature by negative
feedback mechanisms.
Mechanisms of Thermal Energy Exchange
Homeotherms and Poikilotherms, Ectotherms and Endotherms
Homeotherm – is an animal that maintains a stable body temperature
regardless of the temperature of the external environment.
Poikilotherm – is an animal whose body temperature varies with, and often
matches, the temperature of the external environment.
Endotherm – is an animal that maintains its body temperature by internal
mechanisms.
Ectotherm – is an animal that maintains its body temperature by absorbing
thermal energy from the environment.
Ectotherms
Thermal Acclimatization – is the process by which an animal gradually
adjusts to temperature changes in its environment.
Endotherms
Torpor, Hibernation, and Estivation
Torpor – is a short-term state of reduced metabolic rate and body
temperature that reduces the demand for energy during the night or day.
Hibernation – is a state of gravity reduced metabolic rate and activity that
enables an animal to survive the winter by reducing the demand for energy
when food is unavailable.
Estivation – is a state of torpor that enables an animal to survive the summer
by reducing the demand for energy.
Other Thermoregulatory Structures and Behaviours