Homeostasis Flashcards
(35 cards)
what is homeostasis
the motivation to maintain optimal conditions for your body
what does the body need for homeostasis
set point - target temp
detection mechanism - change in temp
mobilisation of behaviour - sweat
who described osmotic thirst as the motivation to seek and ingest water
Fitzsimmon, 1998
what does our body need the right balance of to function
sodium and water
what disrupts the internal balance of sodium chloride that causes osmotic thirst to occur
salt
what happens when we eat too much salty food
the amount of sodium chloride increases so it is no longer at its set point
what can the increased sodium chloride make the intercellular fluid do
leave the cells which creates more pressure for any remaining fluid in the cells to leave
now that the fluid in the cells have been pulled out to create more fluid outside of the cells, what does this cause for the inside of the cells
dehydration
what does the dehydration in the cells cause
signals to the brain saying we need water - this is osmotic thirst - the motivation to seek water
how can we restore the balance of sodium chloride so that more fluid can be moved back into the cells
by drinking water - mobilisation of water
how is the endocrine system involved in osmotic thirst
osmoreceptors in the hypothalamus notice when sodium chloride has increased from the salty foods
the hypothalamus releases ADH into the pituitary gland which can then be released into the bloodstream
ADH reaches the kidneys where it constricts blood vessels and increases the permeability of the renal tubes - both of which help to save water so that no water is unnecessarily lost such as through urine
the less water lost, the quicker sodium chloride can return back to set point
what happens when we drink more water than we need to
the osmoreceptors sends signals to the hypothalamus to stop the release of ADH so there’s less pressure on the kidneys to save water
what is hypovolemic thirst
your body loses both water and solutes such as sodium chloride
how may hypovolemic thirst happen
vomiting, injury
when you injure yourself or be sick, your body is losing a lot of water and solutes. what does this cause for the kidneys
causes them to struggle saving water as its being lost
what is the process of hypovolemic thirst in the endocrine system
ADH is released from the hypothalamus to the pituitary gland where it then enters the bloodstream
it then enters the kidneys where it releases angiotensin II and aldosterone to tighten blood vessels and save sodium from being lost in urine
what is metabolism
the process of breaking down food into energy for functioning
what are 2 processes of metabolism
anabolism - build molecules
catabolism - break down molecules
why has evolution shaped us to be release more hunger signals
food availability
when we eat, what does our body break down our food into
glucose - carbs
fatty acids
amino acids
what is released to control how much energy goes into certain systems after eating
insulin
what does insulin help the body to do
glucose moves into storage
amino acids help repair
fatty acids stored as fat
what are the 2 types of diabetes
type 1 - not enough insulin produced
type 2 - insensitive to insulin
who found that the body has a set point for weight and when people lose weight, their body fights to return to the set point by lowering metabolic rates
Fothergill, 2016
