Module 5: Homeostasis Flashcards
What is homeostasis
maintenance of a condition of equilibrium or of a near constant internal conditions
What conditions in the body need to be maintained by homeostasis
- temperature
- water content
- glucose
What is negative feedback
a control mechanism which can detect change, which responds by restoring the change back to the norm
What are the stages of negative feedback
- normal level
- level changes from the norm (increases or decreases)
- receptor detects change (thermoregulatory receptors, pancreas)
- communication via nervous system or endocrine system
- effector responds (muscle or glands)
What is positive feedback
applies change away from normal
this is not involved in homeostasis
What are the stages of positive feedback
- Normal level
- level changes from norm
- receptor detects change
- communication via nervous system or endocrine
- effector responds by moving the change more away from the norm
What is an endotherm
an animal that controls body temperature internally by homeostasis
What do endotherms do to cool down
to cool down
- sweating
- hairs lie flat
- vasodilatation
What do endotherm have to increase temperature
to increase temperature
- shiver
- increase metabolic rate
What do endotherms do to conserve temperature (keeping warm)
- vasoconstriction
- hairs stand up
- shivering (contraction and relaxation of muscles)
What is an ectotherm
animals cannot control their body temperature internally, they absorb heat from the envioroment
How do ectotherms obtain heat
- conduction
- convection
- radiation
What behavioural responses do ectotherms do
- sun bathing
- increases SA to let in radiation or to let out heat
- burrowing to help them cool down
- going into water to cool down
- going into shade to cool down
What physiological responses do ectotherms do
changing colour: darken their colour to allow more heat to be absorbed
