U1AOS2 Homeostasis Flashcards
Homeostasis
Maintenance of the narrow limited conditions of the internal environment
Stimulus response model
Stimulus => receptor => control centre=>
Effector => response
Negative feedback
Response produced by the effector counteracts the stimulus
Homeothermy
Maintenance of the bodies temperature, which is measured by the hypothalamus inland maintained through physiological and behavioural negative feedback. 36.7
Vasodilation
Widening of the arterioles to reduce body temperature
Vasoconstriction
Tightening of the blood vessels when body temperature is too low
Poikilothermy
Animals that regulate their behaviour through only behavioural and structural adaptations
What is glucose stored as?
A polysaccharide called glycogen
Purpose of the islets of langerhans
Measure blood glucose concentration and real ease insulin and glucagon.
Insulin
Released from beta cells when blood glucose is too high, and stimulates the liver to convert glucose to glycogen
Glucagon
Released from alpha cells when glucose is too low and stimulates the liver to convert glycogen to glucose
How does water enter the body?
Drinking, eating and metabolic water from cellular respiration
How does water leave the body?
Sweating, breathing, urination and defaecation
Regulation of water balance
ADH is released in response to high blood tonicity to increase the amount of water reabsorption in the nephron
