topic 7 co ordination control + homeostasis

Question 1

what is the gland that produces adrenaline?

Answer 1

adrenal gland

Question 2

what does adrenaline do?

Answer 2

causes liver cells to break down glycogen into glucose and release it into the blood

Question 3

what are the effects of adrenaline?

Answer 3

increases uptake of glucose from blood by liver cells
increases blood pressure
increases heart rate

Question 4

how does adrenaline prepare the body for fight or flight?

Answer 4

increases blood flow to vital organs (not the digestive system)

breathing rate increases for more oxygen for aerobic respiration

heart rate increase is needed to pump more blood around the body

Question 5

what does metabolic rate mean?

Answer 5

the rate in which energy in food is transferred by all the reactions in your body to keep you alive

Question 6

how are thyroxine levels controlled when too high?

Answer 6

inhibits TRH from hypothalamus

lack of TRH means pituitary gland is inhibited

release of TSH is inhibited by the pituitary gland so lack of TSH

less thyroxine in the blood

thyroxine levels return to normal

Question 7

how are thyroxine levels controlled when too low?

Answer 7

registered by hypothalamus

TRH stimulates pituitary gland to release TSH

TSH stimulates thyroid gland to release thyroxine

thyroxine levels in the blood increase

thyroxine levels return to normal

Question 8

homeostasis definition

Answer 8

regulation of internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and external changes

Question 9

comparison of waist hip ratio and type 2 diabetes

Answer 9

more weight around hips leads to increased risk of type 2 diabetes

Question 10

higher bmi means

Answer 10

higher risk of type 2 diabetes

Question 11

what happens when glucose levels are too high?

Answer 11

pancreas releases insulin
insulin travels to liver
liver converts glucose into glycogen
glucose levels decrease
glucose levels return to normal

Question 12

what happens when glucose levels are too low?

Answer 12

pancreas releases glucagon
glucagon travels to liver
liver converts glycogen into glucose and releases it into the blood
glucose levels increase
glucose levels return to normal

Question 13

role of LH

Answer 13

stimulates ovulation on day 14, and it releases egg and grows the corpus luteum

Question 14

role of FSH

Answer 14

causes secretion of oestrogen
matures the egg

Question 15

how oestrogen, LH and FSH interact to prepare body for fertilised egg

Answer 15

FSH causes oestrogen increase and matures the egg
Oestrogen prepares the lining
LH releases the egg on day 14

Question 16

two hormones given to women in IVF

Answer 16

FSH and LH to stimulate egg production

Question 17

why is LH and FSH used in clomifene therapy

Answer 17

it stimulates egg maturation and ovulation, so the couples know when the egg is going to be released when they have intercourse, increasing chances of pregnancy

Question 18

what causes type 1 diabetes, what is it and how to treat?

Answer 18

genetics
when body does not produce any/enough insulin
inject insulin into fatty tissue

Question 19

what causes type 2 diabetes, what is it, and how to treat?

Answer 19

unhealthy diet, little exercise
it is when the body becomes immune to insulin
controlling diet and exercising can help

Question 20

explain steps of dialysis

Answer 20

blood is taken from the patient, and it is separated from the dialysis fluid by a partially permeable membrane

dialysis fluid contains same concentration of glucose and salts as normal blood so there is no net movement of glucose out of the blood by diffusion

excess salts diffuse into dialysis fluid

there’s no urea in the fluid so it diffused from the blood into the dialysis fluid

the blood and the dialysis fluid then move in opposite directions across the membrane to maintain concentration gradient

then clean blood is returned to patient

Question 21

how long does dialysis take and how often

Answer 21

several hours for two to three times a week

Question 22

explain osmoregulation when blood concentration of water is too high

Answer 22

hypothalamus detects water concentration is too high

pituitary gland stops releasing ADH

walls of the collecting duct become less permeable to water

water is transported to the bladder and excreted in urine

normal blood concentration of water

Question 23

explain osmoregulation when blood concentration of water is too low

Answer 23

hypothalamus detects too low water concentration

pituitary gland releases ADH

collecting duct walls become more permeable to water

water is absorbed via osmosis from the collecting duct back into blood

normal concentration of water

Question 24

negative effect of hormones in clomifene therapy

Answer 24

can mature and release too many eggs due to high FSH and LH which could be dangerous for mother as they could all be fertilised then she would have like lots of babies

Question 25

What does nephron do

Answer 25

regulates water and soluble substances in the blood by filtering the blood, reabsorbing what is needed, and excreting the rest as urine.

Question 26

Urea, water, ions pass through where

Answer 26

Bowman’s capsule then filter into the nephron

Question 27

kidney cycle

Answer 27

blood enters the kidney through an artery containing urea kidney removed urea and excess ions and excess water leaves kidney as urine blood leaves through veins and now contains no urea

Question 28

nephrons

Answer 28

filtration: occurs in glomerulus. urea, water, ions and glucose are small enough to pass out of the capillaries into the bowman’s capsule selective reabsorption of glucose and ions: substances in the bowman’s capsule move into the tubule and at a point called the proximal convoluted tubule, glucose lost during ultrafiltration is selectively reabsorbed into blood reabsorption of water and ions - water and ions are reabsorbed at the collecting ducts of the tube

Question 29

thermoregulation

Answer 29

found in hypothalamus if temperature becomes too high: humans sweat. the sweat glands are located in the dermis layer of the skin sweat is released onto the surface of the epidermis **vasodilation** means more blood flows closer to the surface of the skin if too cold: no sweat shivering to generate heat from respiration hairs stand on end to create an insulating layer **vasoconstriction** means blood does not flow close to the surface which results in less heat loss