homeostasis in action

Question 1

how is temperature regulated in the body?

Answer 1

1. thermal receptors detect the body temperature from the blood flowing in the brain. (and skin)
2. the thermoregulatory centre triggers effectors automatically.
3. effectors produce a response.

Question 2

how is temperature changed in the body?

Answer 2

too hot - sweat is produced from sweat glands and evaporates from the skin, blood vessels supplying the skin dilate so more blood flows close to the skin surface.
too cold - hairs stand up to train insulating air, no sweat, blood vessels supplying the skin constrict to reduce blood supply, muscles shiver.

Question 3

what is insulin?

Answer 3

a hormone that tells the liver to make glucose into glycogen.

Question 4

what is glucagon?

Answer 4

a hormone that tells the liver to make glycogen into glucose.

Question 5

what is diabetes and what are the 2 types?

Answer 5

diabetes - a condition that affects the ability to control blood sugar level.
type 1 - the pancreas doesn’t make enough insulin so glucose levels are too high. (insulin injection)
type 2 - cells don’t respond to insulin. (exercise and controlled carbohydrates)

Question 6

what does the kidney do?

Answer 6

filters substances out of blood as it passes through to make urine. (useful substances are reabsorbed - selective reabsorption)

Question 7

what substances are removed in urine? (3)

Answer 7

urea - proteins can’t be stored in the body so are converted to carbohydrates in the liver (deamination), ammonia is a waste product that is converted to urea in the liver and is filtered out in the kidney.
ions - if ion content in the body is wrong too much or too little water enters the cells (osmosis), ions are filtered by the kidney and the right amount is reabsorbed.
water - pretty simple

Question 8

how is the concentration of urine controlled?

Answer 8

a hormone called ADH produced in the pituitary gland. (brain monitors water content)

Question 9

what is dialysis treatment?

Answer 9

machines do the kidney’s job.

Question 10

how does a dialysis machine work?

Answer 10

1. blood flows between partially permeable membranes surrounded by dialysis fluid.
2. dialysis fluid has the same concentrations as healthy blood.
3. only ions and waste can diffuse across the membrane.