excretion Flashcards
Compare and contrast excretion and secretion
Excretion - harmful substance. (urea,co2,bile pigments)
Secretion - useful product (hormone enzymes)
both require ATP
how are excess proteins turned into urea
converted into amino acids
undergo deamination - making ammonia
through the ornithine cycle makes urea
what does the PCT reabsorb
All glucose and amino acids
some inorganic ions
water - based on bodies needs
how is the PCT adapted for its function
Highly folded microvilli are present to increase surface area
Many co transporters - facilitated diffusion of sodium ions, larger glucose ions
at what part of the nephron are the walls impermeable to water
Ascending limb
How does the Loop of Henle produce urine
Lowers Ψ in order to make a Ψ gradient.
descending limb: water moves out as its permeable to water. ( ions aren’t permeable.)
ascending limb :active transport of ions out (impermeable to water.)
lower Ψ outside of collecting duct then inside so water moves in - making urine.
explain the process of ultrafiltration
Afferent arteriole is wider then the efferent arteriole
high hydrostatic pressure is made
liquid is forced put through the fenestration’s in the endothelium.
Basement membrane stops large substances passing through
podocytes are finger like projections allowing for further filtering
what are aquaporins
Aquaporins are channels in the cell surface membrane that allow water molecules to pass through
Explain how the stick detects this pregnancy hormone.
hcg can pass into the filtrate int he bowman’s capsule
monoclonal antibodies on the stick are complimentary to the hcg
antibodies are attached to a dye which appear when you are pregnant
Suggest why a high intake of protein in the diet will be likely to result in a high concentration of urea in urine.
many amino acids which cant be stored in the body , are converted into urea via deamination - making ammonia - then the orthine cycle produces urea . which is cannot be stored int he body for too long and is then excreted out from the body in the urine.
Define excretion
removal of metabolic waste from the body
Why do we have to remove waste products from the body
so waste products dont build up and inhibit enzyme activity
to maintain blood concentration substances
Name 3 waste products
Co2
Nitrogenous compounds - urea
Bile pigments - broken down haemoglobin
What’s the function of the Hepatic artery
oxygenated blood supplied to the hepathocytes
What’s the function of the Central Vein
takes deoxygenated blood away from the liver
What’s the function of the hepatic portal vein
takes deoxygenated blood from the digestive system
What may the hepatic portal vein have
toxic compounds
What’s the function of the sinusoid
Where blood from the hepatic artery and hepatic portal vein mix
this increases oxygen concentration
What’s the function of the kupffer cells
act as macrophages - injest foreign materials
What’s the function of the hepathocytes
secrete bile into the bile caniculi
What’s the function of the bile caniculi
where bile is drained into and is transported into the gall bladder
Outline 3 functions of the liver
- store glycogen - when insulin levels rise
- detoxification - enzymes break down harmful substrates
- Forming urea
How is urea formed in the liver
Amino acids deaminate and form ammonia and a keto acid . Amino group gets removed
Ammonia gets used in the ornithine cycle and gets converted into urea.
Keto acid is used in respiration
