B12 Flashcards
what is thermoregulation
its the control of our internal body temperature
where is the thermoregulatory centre located
in the hypothalamus
what does the thermoregulatory centre do in our body?
it act like a thermostat in our body
what are three things our bodies do when we’re too cold
shiver - skeletal muscles shake to create heat
vasoconstriction - blood capillaries constrict to reduce heat being lost
sweats less - reduces heat being lost
what are three things that our bodies do when we’re too warm
vasodilate - blood capillaries expand causing more heat to be lost
sweat - as the h20 evaporates so does the heat energy
erector muscles relax - causes your hair to curve towards your skin
what is the optimum temperature for the human body
37 degrees Celsius
why does the body need to be at 37 degrees Celsius
its the optimum temperature for enzymes too work
what is the main job of the kidneys?
to filter the blood and send urea waste into the gall bladder to be excreted by the body in the form of urine
where in urea made in the body
in the liver
what is the other job of the kidney
to regulate levels of useful things like ions and water
what is excretion
the removal of toxic waste products in the body
what is egested
egestion is the removal of undigested food by the body
name some products which are excreted by the body
excess water
nitrogen ions
urea
carbon dioxide
how does water leave the human body
when we exhale water vapour is released form our lungs
what is our urine made of
water, urea and salts
how is urea made
when excess proteins are broken down they form ammonia which is then turned into urea in a process called deamination
why is urea dangerous to our body
it’s very toxic to the human body so it needs to be removed
why does CO2 need to be removed by the body
its very acidic to the body and so will cause enzymes to denature due to the changing of the pH and so will stop or really slow down chemical reactions
how is urea removed from the body
urea is made in the liver and then it goes into the blood where it travels to the kidneys where the blood is filtered for urea. the urea then gets to the bladder where its mixed with other salts and water so the urea is excreted from the body in the form of urine.
name the order of parts of the kidneys (in the nephron) starting from the bowman’s capsule and describe what happens there
1- bowman’s capsule- water, glucose and urea leave the blood and enter the bowman’s capsule
2- first convoluted tube- glucose is reabsorbed into the blood by active transport
3- loop of Henle- water is reabsorbed back into the blood by osmosis. some of the water is reabsorbed. not all of it
4- second convoluted tube- don’t need to know
5- collecting duct- water is also reabsorbed back into the blood. some of it is
6- Ureter- connects the collecting duct and bladder
7- Bladder- stores urine
through what does water, urea and glucose pass through into the bowman’s capsule
they pass through a partially permeable membrane
what is the glomerelus
a series of blood capillaries surrounding the bowman’s capsule
what is an adaptation of the first convoluted tubule
it’s surrounded by blood capillaries so there is a large surface area.
has tons of microvilli which increases the surface are further and so increases the rate of active transport
has tons of mitochondria to produce the energy needed for active transport
what is deamination
when nitrogen is removed from the amino acids to form ammonia
name the 6 main parts of a kidney
renal artery - artery carrying oxygenated blood to the kidneys
renal vein - takes blood away from the kidneys
cortex - filters large molecules form the blood like blood cells
renal pelvis - collects urine
medulla - where urea, water and salt are removed form the blood
ureter - carries urine from the kidneys to the bladder
how does ADH control the amount of water in the body
the water levels in the blood are monitored by the brain.
if water are too low, ADH is released and travels to the kidneys where the tubules in a nephron in the kidneys becomes more permeable to absorb more water from the tubules to raise water levels back into the blood.
if water are too high, the pituitary gland stops releasing ADH so the tubules in a nephron in the kidneys becomes less permeable to absorb less water from the tubules to lower water levels back into the blood.
what type of loop is ADH controlling water levels called
a negative feedback loop
which drug is used to reduce the risk of organ rejection
cyclosporine
how does a dialysis machine work
a needle in injected into the patient which transports blood into the dialysis machine. the blood passes goes into a partially permeable tube which allows small particles to pass through. On the other side of the tubule is dialysis fluid which has a normal concentration of water, minerals, glucose and ions but does not have any urea in it so there’s a huge concentration gradient for urea so all the urea from the blood goes into the dialysis fluid. new dialysis fluid passes into the machine every second so there won’t be a chance for the concentration gradients to balance out. once the urea is removed from the blood, the blood goes back into the patients body.
how does a kidney transplant work
the kidney which has failed is replaced with a healthy kidney which is given by a donor.
what are the advantages and disadvantages of a dialysis machine
advantages:
are more available than kidney transplants
disadvantages:
need to frequently go to the hospital for treatment
treatment may take hours
many people feel ill during treatment
what are the advantages and disadvantages of having a kidney transplant
advantages:
solves the problem of kidney failure
can lead a normal life
long term cheap
disadvantages:
expensive
risk of organ rejection
