excretion and the kindey Flashcards
What is egestion
the removal of faeces
what is excretion
the removal of toxic waste substances which have been made by cells
what needs to happen is there excess amino acids
need to be broken down so they can be excreted
what are amino acids broken down into
carbohydrates and ammonia
why is ammonia converted into urea
ammonia is very toxic
what are the three main sections of the kindey
cortex - outside
medulla - middle
pelvis - centre
what is the first stage that occurs in the nephron
ultrafiltration
how is the glomerulus formed
build up of pressure in the capillaries
What does the pressure in the glomerulus cause
small molecules are forced out of the glomerulus into the bowmans capsule
what are the small molecules that form the glomerular filtrate
urea
glucose
amino acids
salts
what happens to the molecules that are too big to be filtered through
stay in the blood
what is the second stage that happens in the nephron
selective reabsorption
where does selective reabsorption occur
PCT
what happens in selective reabsorption
useful materials are moved by specialised cells from the nephron back to the blood by active transport
what materials are reabsorbed into the blood
all glucose
all amino acids
some salts
most water
