B12- Homeostasis in action

Question 1

3 waste products that need to be removed?

Answer 1

CO2, urea, water

Question 2

CO2
Produced from?
Dangers of it in body?
Removed how?

Answer 2

Respiration
Can form acidic conditions
Exhaling, diffuses from blood into alveoli

Question 3

Urea
Produced from?
Dangers of it in body?
Removed how?

Answer 3

Breakdown of excess amino acids
Can form ammonia which is toxic
Filtered by kidneys, leaves body as urine

Question 4

Water
Dangers of it in body?
Removed how?

Answer 4

Stops cells functioning if lose or gain too much water
Sweating, exhaling, urine

Question 5

What process are controlled and not controlled to remove water and urea?

Answer 5

Controlled- Urea and water in urine
Not controlled- Water in sweat and exhalation

Question 6

How do kidneys work and what do they do?

Answer 6

They filter the blood every 5 mins and move only smaller molecules from the blood to the kidney tubules. Including glucose, urea, water and mineral ions.

Question 7

Which substances are reabsorbed after filtration and how much of them?
What is the process called?

Answer 7

All glucose is reabsorbed for respiration and some water and mineral ions are needed back into the blood. None of the urea is needed back in the blood.
Selective reabsorption

Question 8

What does ADH stand for?

Answer 8

Antidiuretic hormone

Question 9

What happens when water levels in blood rises?

Answer 9

Detected by hypothalamus that blood is diluted–> Tells pituitary gland to release less ADH–> Kidneys reabsorb less water–> High volume of dilute urine–> Optimal water levels in blood

Question 10

What happens when water level in blood falls?

Answer 10

Detected by hypothalamus that blood is concentrated–> Tells pituitary gland to release more ADH–> Kidneys reabsorb more water–> Low volume of concentrated urine–> Optimal water levels in blood

Question 11

What happens when large quantities of proteins are digested/ what does it cause?

Answer 11

Excess amino acids build up, are converted to ammonia in the liver. Ammonia is toxic, liver converts it to urea as it is safer

Question 12

2 solutions to kidney failure?

Answer 12

Dialysis and kidney transplant

Question 13

How does dialysis work?

Answer 13

Unfiltered blood pumped to dialysis machine, blood thinners added. Then passes dialysis fluid surrounded by a partially permeable membrane. The fluid has the same conc of glucose and ions of a healthy person’s blood and no urea. Molecules diffuse across the membrane. The waste in the fluid is removed. Clean blood returns to the person through a bubble to top to remove bubbles.

Question 14

Dialysis
Ads and Dis

Answer 14

Ads- Available to all kidney patients, no major surgeries
Dis- Needs a strict diet, expensive for NHS

Question 15

Kidney transplant
Ads and Dis

Answer 15

Ads- less time taken out of life, eat and drink anything
Dis- have to take immunosuppressant drugs, shortage of organ donors