Kidneys Flashcards
How body looses water
. Lungs when we exhale
. Sweating
- also contains ions and urea
- part of temp control system
. Kidneys in urine
How body deals with excess amino acids
- liver breaks down excess amino acids + produce ammonia
- liver converts ammonia to urea
- excreted by kidneys
Describe how urea leaves body
- blood enters kidney in artery
- blood contains urea
- kidney revives urea + excess ions
- leave kidney as urine + stored in bladder
- blood leaves in vein
Adh
Increases permeability of collecting ducts
= more water reabsorbed into blood
= less water means less urine
Where is ADH produced
Pituitary gland
= stops you excreting water by causing the collecting duct to be more permeable
= more water is reabsorbed
Describe a nephron
Tiny tubes inside a kidney
Describe kidney stones
- high salt and minerals in diet can lead to stones
= very painful
Describe renal damage
- kidney no longer able to filter blood
- plasma not properly reabsorbed
- proteins and cells pass through bowman’s capsule
Adv of dialysis
- cheaper
- can do at home
Why does urine contain mineral ions and urea but not glucose or protein
- proteins aren’t filtered
- glucose is filtered and reabsorbed
- ions are filtered and some reabsorbed
- some urea is reabsorbed
How is urea made
Made in liver during process of deamination
= excess amino acids converted to fats and carbs for storage
Functions of kidney
Filter blood
Remove waste like urea
Regulate useful things like water and ions
What happens if water too low
Hypothalamus detects water conc in bloodstream
Sends signal to pituitary glands
Releases hormone ADH
Tells tubules in kidney to reabsorb more water
= less urine
What happens if water levels too high
Hypothalamus detects water conc in bloodstream
Stops sending signals to pituitary gland
Won’t release as much ADH
Tubules absorb less water
More urine
Describe dialysis
Patients blood passes over semi permeable membrane
= allow ions, urea and water through
= won’t allow larger molecules like proteins through
Other side of membrane has dialysis fluid
= contains normal conc of water and ions but no urea
Urea diffuses from blood into dialysis fluid
Dialysis fluid constantly refreshed
= ensures large conc gradient for urea