chapter 6 excretion Flashcards
what are the main excretory products produced by cells
water, mineral salts, urea, carbon dioxide
what are the main excretory organs
lungs, skin, kidney
what do the lungs excrete
carbon dioxide
what do the skin excrete
sweat
what do the kidneys excrete
urine - this contains urea, mineral ions, and other waste substances
where is urea made
in the urea
what are the short term and long term effects of alcohol
they interfere with cell processes
damage kidneys
lack of coordination, slows nervous system down
liver poisoning
what do the two kidneys do
pass urine to the bladder for storage
what does a healthy kidney do
filters the blood reabsorbs all the sugar sufficient ions sufficient water removes all the urea
what is the relationship between urine concentration, sweating and exercise
when we are short of water due to increased sweating due to exercise we pee less - dark and concentrated
when we have a lot of water due to decreased sweating and decreased exercise we pee more - dilute and pale
how does a dialysis machine work
blood is separated from the dialysis fluid by a partially permeable membrane,
proteins cannot pass through as they are too large
the dialysis fluid contains the same concentration as sufficient ions and glucose so they are reabsorbed
all urea is filtered out
excess water leaves by osmosis
it then goes through a bubble trap to get rid of any bubbles
what are the advantages and disadvantages of haemodialysis
\+patient kept alive while waiting for a transplant \+suitable for patients with abdominal scares and wounds who cannot have peritoneal dialysis - many visits to hospitals - restricted holidays - costs a lot - possible infection from equipment - availability of machines and staffs - dietary resticitions
what are the advantages and disadvantage of peritoneal dialysis
+ patient kept alive while waiting for transplant
+ can be done at home
+ only bags of fluid needed while traveling
+ diet may be less restricted
- patient has to have strict hygienic conditions
- cost a lot
not suitable for people with abdominal scars
regular monitoring
what are the advantages and disadvantages of kidney transplants
\+ not dependent on machines \+ less long term cost \+ diet less restricted - risk of rejection - immunesuppresent drugs - cost a lot - check ups donor availability
what are the organs involved in excretion
liver - produces urea
renal artery - brings blood containg urea and other substances to the kidney
renal vein - carries blood away from the kidney after filteration
bladder - stores urine
urethra - passes to outside of the body
ureter - urine passes from kidney to bladder
