Integration and homeostasis Flashcards
Krogh’s Principle
for large number of physiological problems only a select number of species are used, due to convenience
homeostasis
consistent internal conditions
negative feedback (with example)
work against change (to move back to constant)
e.g. for 21 days of menstrual cycle
positive feedback
work to increase the change (to move away from constant)
e.g. for 7 days of menstrual cycle/ contractions when giving birth
water salt balance hormone & details
vasopressin
located in paraventricular nucleus of hypothalamus and supraoptic nucleus (SON)
regulates fluid balance (antidiuretic hormone (ADH))
example of behavioural homeostasis
lizard moves to high heat to raise temperature
lateral hypothalamus function
regulating food consumption
detects hormones, levels of glucose
what does an orexogenic molecule do?
increase food intake
signals from fat cells to kidneys
what does an anorexogenic molecule do?
decrease food intake
signals from fat cells to kidneys
rheostasis (with example)
long-term regulation of physiological change
e.g.) migration/hibernation
what is programmed rheostasis?
obligatory at certain phases of life
what is reactive rheostasis?
in direct reaction to unpredictable events
e.g.) long term increase in temp. when
NB. a few days = long term
epigenetic modifications
methylation and acetylation
biochemical modifications
EXTRA INFO
what happens when no antidiuretic hormone
no water can pass through cell ducts
if [Na] low in blood, doesn’t secrete ADH
