negative feedback Flashcards
what is blood glucose controlled by
the pancreas
what hormone does pancreas produce
insulin
in what body cells is insulin stored in
in liver and muscle cells
what happens when blood glucose levels are too low
- pancreas release glucagon hormone into bloodstream
- glucagon triggers liver cells to convert glycogen back to glucose and this glucose is released into the blood
- this causes blood glucose concentration to return to normal
what happens when blood glucose levels are too high
pancreas senses change in blood conc
pancreas produces insulin
- insulin travels in the bloodstream and around the body
- this triggers body cells to take up glucose from the blood
- insulin is stored in liver and muscle cells
- conc of blood glucose returns to its normal level
what are the general stages of negative feedback
- if the level of something rises, control systems reduce it
- if the level of something, control systems rise it
what happens if thyroxine levels in the blood are too low
- pituitary gland releases TSH
- thyroid releases more thyroxine
- blood levels return to normal
what happens when adrenaline enters the bloodstream
- increases breathing rate, heart rate, and since heart beats faster, more glucose and oxygen reaches the brain and muscle, increased aerobic respiration to prepare us for fight or flight
conversion of glycogen to glucose so more energy is released in the muscles
it diverts blood away from areas, such as the digestive system, towards the muscles
what happens when there is not enough water in the body
if the blood becomes too concentrated, the pituitary gland releases hormone ADH into the bloodstream
- ADH travels to the kidneys, causing the kidney tubules to become more PERMEABLE to water
- more water is reabsorbed back into the blood
- less urine is produced
what happens when there is too much water in the body
- conc of water in the blood rises
- pituitary gland stops releasing ADH
- kidneys reabsorb less water
- more urine produced
how is water lost
- via the lungs during exhalation.
- Water, ions and urea are lost from the skin in sweat.
- via the kidneys in urine
how are excess water, ions and urea removed from the body
through the kidneys in urine
what happens if body cells gain or lose too much water via osmosis
they cannot function efficiently
what is glucose used for
respiration
after a meal of …. , the concentration of blood glucose will rise
carbohydrates
