excretion Flashcards
define excretion
removal of substances in excess, toxic waste and waste from metabolism and
explain the differences between excretion and defecation
defecation is undigested material that has passed though gut and is not a waste product form metabolic reaction
which organ removed urea?
kidney
name substances that need to be removed
co2 nitrogenous waste used hormones excess substance like water and ions toxins
what does liver remove
bile pigments from breakdown of haemoglobin
define deamination
removal of nitrogenous containing part of amino acid to form urea
describe the process of deamination
- enzyme breaks down protein into amino acid
- amino acid is absorbed into blood, and the hepatic portal vein takes the amino acid to the liver
- in the liver, excess amino acid is split
- energy containing part of amino acid gets turned into carbohydrates and stored while nitrogen is turned into urea
name the function of the liver
makes bile converts excess urea and carbohydrates controls amount of glucose in the blood breakdown old RBC storing iron and excreting remains of haemoglobin as bile pigments break down harmful substances
what is the function of urea
excretes urea and other metabolic waste
maintain water balance
regulate mineral ions of body fluid
regulate pH of body fluid
draw a kidney and label it
cortex medulla pelvis ureter bladder urethra
what is the function of nephron
filters wasted fro, blood and regulates water and mineral salt content in blood
what is the function of convoluted tubules
reabsorption of useful substances
what is the function of glomerulus
filtration
draw a nephron
bowmans capsule & glomerulus proximal convoluted tubule loop of henle distal convoluted tubule collecting duct
explain the process of ultrafiltration
- blood is moved from renal arteriole into glomerulus
- high hydrostatic pressure forces fluid out of capillaries
- fluid enters bowman’s capsule
what is insude the glomerular filtrate
amino acid water mineral salt glucose urea
name 2 substance that is not in the glomerular filtrate and why
red blood cells and plasma protein bc they are too big
why is the blood vessel brining the blood into the glomerulus larger than the capillary taking it away
so blood cannot get away easily
where does reabsorption happen?
proximal convoluted tubules
distal convoluted tubule
loop of henle
what does each tubule absorb?
PCT: all nutrients and some water and mineral salts
LOH, DCT, CT: water and mineral salts
explain secretion
happens at DCT via active transport
substances secreted is urea, toxins, drugs and excess mineral salts
urine is fromed at collecting tube and sent to bladder to be stored
what controls the release of urine
sphincter muscle
explain how kidney dialysis works
dialyser is a membrane that allows certain substances to pass through
the dialyser is surrounded by dialysis fluid
as blood goes through, substance in excess will diffuse out
what does kidney dialysis do
help maintain salt balance, glucose and water concentration
removes urea and other toxins from blood
what is the concentration for urea, glucose water and salts in dialysis fluid
urea- none
the rest: same
what is important when doing dialysis
same body temp
composition of dialysis fluid
constantly change dialysis fluid
what is immunosuppressants and an disadvantage
drugs used to stop WBC from working to decrease chance of organ rejections
stops immune system from working so person is likely to get sick
advantages of kidney transplant
patient can return back to normal lifestyle
dialysis machine can be made available for other ppl
disadvantage of kidney transplant
need suitable donor
rick of rejection
expensive
