🟣Osmotic Changes / Osmoregulation / Kidneys Flashcards
Hypotonic
More dilute solution outside the cell
Water moves in
Cells swell / burst
Hypertonic
More concentrated solution outside the cell
Water moves out
Cells shrivel
Isotonic
Concentration inside cell = outside cell
Water moves in and out at a constant rate (overall no net movement of water)
Cell = Turgid / stable
How’s water lost by the body?
Water vapour by exhalation in the lungs
Water + ions + urea kidneys in urine
Water + ions lost in sweat - skin
What’s produces from the digestion of proteins?
Proteases —> amino acids
Excess amino acids —> deaminated into ammonia which is toxic so it’s converted to urea for ex creation (Liver)
Function of the kidneys
Filtration - glucose / mineral ions / urea / water - into nephron
Reabsorption - all glucose reabsorbed (active transport / diffusion), amount of water + mineral ions reabsorbed depends on the body’s concentration of these (selective reabsorption)
Excretion - all urea + excess water + mineral ions passed to bladder for excretion
Ways to treat kidney failure
Organ transplant
less fluctuations / extends life
immunosuppressants
Risk of rejection - tissue typing
Surgery risks - infection / anesthetic
Ways to treat kidney failure
Dialysis
Needle put in the artery, blood then goes through the dialysis machine, urea removed + salt reduced
Removes waste / common
Costly-NHS / controlled diet / anticoagulants / fluctuations as it’s not constant / 4x a week for 8h a day
What does the body do if water concentration is too high?
Blood water content rises, more dilute blood, message sent to pituitary gland
Less ADH released
Kidney tubules less permeable
Less water reabsorbed - more in urine
What does the body do if water concentration is too low?
Blood water content falls, more concentrated blood, message sent to pituitary gland
More ADH released
Kidney tubules more permeable
More water reabsorbed - less in urine
What is osmoregulation?
Regulation of water concentration in the blood
Negative feedback loop
