Topic L- Execretion Flashcards
definition of excretion
removal of waste products of a chemical reaction
definition of egestion
removal of left over substances or unused material ( which hasn’t been part of a chemical reaction)
Name 3 excretory organs
Kidneys
Lungs
Skin
what do lungs excrete
carbon dioxide
what does skin excrete
sweat
what doe the kidneys excrete
urine = urea
ions ( salt)
water
where is urea produced and from what
in the liver from excess amino acids
what parts are contained within the urinary system
7 things
Vein Artery Kidneys Ureters Bladder Sphincter muscle Urethra
PAPER 2
describe structure of a nephron
8 things
Renal artery Glomerulus Bowman's capsule Proximal convoluted tubule Loop of Henle Distal convoluted tubule Collecting duct Blood to renal vein
PAPER 2
ultrafiltration in bowman’s capsule
- blood from renal artery flows through glomerulus
- High pressure = water, urea, ions + glucose (glomerular filtrate ) squeezed out of blood into Bowman’s capsule
- Membrane between blood vessels in glomerulus and bowman’s capsule = filters= proteins + blood cells ( big molecules not squeezed out but remain in blood.
PAPER 2
what is the filtered liquid in the Bowman’s capsule known as
glomerular filtrate
PAPER 2
what is glomerular filtrate composed of
water
urea
ions
glucose
PAPER 2
what happens at the collecting duct
water is reabsorbed from the collecting duct into the bloodstream by osmosis
PAPER 2
what happens at the proximal convoluted tubule
all the glucose reabsorbed from the proximal convoluted tubule back in to blood stream by active transport
PAPER 2
why does reabsorption of glucose occur at the proximal convoluted tubule
so the glucose can be used in respiration