B12

Question 1

what is thermoregulation

Answer 1

its the control of our internal body temperature

Question 2

where is the thermoregulatory centre located

Answer 2

in the hypothalamus

Question 3

what does the thermoregulatory centre do in our body?

Answer 3

it act like a thermostat in our body

Question 4

what are three things our bodies do when we’re too cold

Answer 4

shiver - skeletal muscles shake to create heat
vasoconstriction - blood capillaries constrict to reduce heat being lost
sweats less - reduces heat being lost

Question 5

what are three things that our bodies do when we’re too warm

Answer 5

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

Question 6

what is the optimum temperature for the human body

Answer 6

37 degrees Celsius

Question 7

why does the body need to be at 37 degrees Celsius

Answer 7

its the optimum temperature for enzymes too work

Question 8

what is the main job of the kidneys?

Answer 8

to filter the blood and send urea waste into the gall bladder to be excreted by the body in the form of urine

Question 9

where in urea made in the body

Answer 9

in the liver

Question 10

what is the other job of the kidney

Answer 10

to regulate levels of useful things like ions and water

Question 11

what is excretion

Answer 11

the removal of toxic waste products in the body

Question 12

what is egested

Answer 12

egestion is the removal of undigested food by the body

Question 13

name some products which are excreted by the body

Answer 13

excess water
nitrogen ions
urea
carbon dioxide

Question 14

how does water leave the human body

Answer 14

when we exhale water vapour is released form our lungs

Question 15

what is our urine made of

Answer 15

water, urea and salts

Question 16

how is urea made

Answer 16

when excess proteins are broken down they form ammonia which is then turned into urea in a process called deamination

Question 17

why is urea dangerous to our body

Answer 17

it’s very toxic to the human body so it needs to be removed

Question 18

why does CO2 need to be removed by the body

Answer 18

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

Question 19

how is urea removed from the body

Answer 19

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.

Question 20

name the order of parts of the kidneys (in the nephron) starting from the bowman’s capsule and describe what happens there

Answer 20

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

Question 21

through what does water, urea and glucose pass through into the bowman’s capsule

Answer 21

they pass through a partially permeable membrane

Question 22

what is the glomerelus

Answer 22

a series of blood capillaries surrounding the bowman’s capsule

Question 23

what is an adaptation of the first convoluted tubule

Answer 23

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

Question 24

what is deamination

Answer 24

when nitrogen is removed from the amino acids to form ammonia

Question 25

name the 6 main parts of a kidney

Answer 25

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

Question 26

how does ADH control the amount of water in the body

Answer 26

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.

Question 27

what type of loop is ADH controlling water levels called

Answer 27

a negative feedback loop

Question 28

which drug is used to reduce the risk of organ rejection

Answer 28

cyclosporine

Question 29

how does a dialysis machine work

Answer 29

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.

Question 30

how does a kidney transplant work

Answer 30

the kidney which has failed is replaced with a healthy kidney which is given by a donor.

Question 31

what are the advantages and disadvantages of a dialysis machine

Answer 31

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

Question 32

what are the advantages and disadvantages of having a kidney transplant

Answer 32

advantages:

solves the problem of kidney failure
can lead a normal life
long term cheap

disadvantages:

expensive
risk of organ rejection