Kidneys

Question 0

What is Ultrafiltration?

Answer 0

1) When a high pressure is built up, which squeezes water, urea, ions, and glucose out of the blood and into the Bowman’s capsule.
2) The Glomerulus and the Bowman’s capsule act like filters - Big Molecules such as proteins and blood are not squeezed out: they stay in the blood.

Question 1

What are the Kidneys’ three main roles?

Answer 1

1) Removal of urea from blood (urea is produces in the liver from the break down of amino acids)
2) Adjustments of ion levels In the blood
3) Adjustment of water content in the blood

Question 2

What happens during the process of reabsorbtion?

Answer 2

As the liquid flows along the nephron, useful substances are reabsorbed:

1) ALL the Glucose is SELECTIVELY reabsorbed - it’s moved out of the nephron and back into the blood against the concentration gradient.
2) Sufficient water is reabsorbed, according to the level of ADH. (This is osmoregulation)

Question 3

After the substances have travelled through the nephron, what substances are left (which have not been reabsorbed) and will pass down to the bladder as urine?

Answer 3

Urea and Excess Water

Question 4

What does ADH stand for?

Answer 4

Anti-Diuretic hormone

Question 5

What hormone controls the amount of water reabsorbed in the kidney?

Answer 5

ADH (Anti-Diuretic hormone)

Question 6

Where is ADH released?

Answer 6

The Pituitary Gland

Question 7

What mechanism controls the process of water content regulation?

Answer 7

Negative Feedback

Question 8

What happens then someone is dehydrated?

Three steps

Answer 8

1) Brain detects water loss
2) Pituitary gland releases more ADH
3) ADH makes kidney reabsorb more water
(You are now hydrated.)

Question 9

What happens when someone is Over-Hydrated?

Three steps

Answer 9

1) Brain detects water gain
2) Pituitary gland releases less ADH
3) Lack of ADH means kidney reabsorbs less water
(You are now hydrated.)

Question 10

Why do some people need Dialysis machines?

Answer 10

Because Patients with kidney failure can’t filter their blood properly, so need the machine to do it for them.

Question 11

Why does dialysis have to be done regularly?

Answer 11

In order to keep dissolved substances at the right concentrations, and to remove waste.

Question 12

Why does Dialysis Fluid have the same concentration of salts and glucose as blood plasma?

Answer 12

So that both of them don’t get filtered out of the blood.

Question 13

The semi-permeable barrier in a Dialysis machine let’s through what substances?
(Give two)

Answer 13

Ions & other waste substances such as Urea

Question 14

The selectively-permeable barrier in a Dialysis machine doesn’t let through what substances?
(Give 1, and explain why)

Answer 14

Protein because it’s a big molecule.

Question 15

Look at CGP guide (page 9) and check the diagram to see whether you know all the steps.

Answer 15

Well fucking done.

Question 16

Why can Kidney Transplants be an issue?

Answer 16

The organ may be rejected - treated like a foreign body and attacked my antibodies.

Question 17

What precautions are taken to prevent kidney rejection from happening?
(Give two)

Answer 17

1) A donor with a tissue type that closely matches the patient is chosen
2) The patient is treated with drugs that suppress the immune system, so that their immune system won’t attack the transplanted kidney.

Question 18

What are some of the drawbacks of Dialysis Machines?

Answer 18

1) They’re expensive for the NHS to run

2) Dialysis isn’t a pleasant experience

Question 19

What four hormones are active in the menstrual cycle?

Answer 19

FSH
LH
Oestrogen
Progesterone