Osmoregulation And The Kidneys

Question 1

What is osmoregulation?

Answer 1

Regulating the water content in our bodies

Question 2

What would happen to body cells is the water content was too HIGH?

Answer 2

• Water moves in by osmosis

- cells may burst (no rigid cell structure like plant cells)

Question 3

What would happen to the body cells if the water concentration in the blood was too LOW?

Answer 3

• Water moves out of the cells by osmosis

- causes cells to shrink

Question 4

What are the 3 roles of the kidneys?

Answer 4

1) removal of urea from the body. Urea is produced in the liver, from the breakdown of excess amino acids
2) Adjustment of ion levels in the blood
3) adjustment of water content of the blood

Question 5

The glomerulus

• What process happens here?
• How does this happen?
• Why does this happen?

Answer 5

• Filtration of blood
• Blood Is squeezed through, allowing glucose,urea and water through. Protein and blood cells are too big to fit through.
• Separates unwanted substances from the blood

Question 6

The first convoluted tubule (proximal)

• what process happens here
• how does this happen?
• why does this happen?

Answer 6

• Selective reabsorption / active transport
• Glucose and Mineral ions are absorbed by active transport
• The glomerulus filtered too many substances and they are reabsorbed into the blood to be used in the body

Question 7

The loop of Henle

• what process happens here?
• How does it happen?
• Why does it happen?

Answer 7

• osmosis
• by reabsorbing water into the blood to create concentrated urine
• The concentration of water is higher in the Loop of Henle than the blood

Question 8

The collecting duct

• what process happens here?
• How does it happen?
• Why does it happen?

Answer 8

• osmosis - water is reabsorbed
• the hormone ADH controls it
• More excess water is absorbed from the loop of Henle, needed for the body to survive

Question 9

What happens if water the blood is too low?

Answer 9

• Pituitary Gland secretes ADH

- Collecting duct becomes more permeable to water-Water passes back into the blood

Question 10

What does ADH stand for?

Answer 10

Anti - Diuretic Hormone

Question 11

What happens when water in the blood is too high?

Answer 11

Water concentration falls

Question 12

Why is dialysis used?

Answer 12

For kidney failure, to filter the blood in a persons body

Question 13

Describe the dialysis membrane

Answer 13

Partially permeable

Permits substances like ions and waste products but not big molecules like protein

Question 14

How do the following move in dialysis?

• salt in the blood
• urea
• sugars and substances needed by the body

Answer 14

• salt moves out of the blood by Diffusion
• urea moves out of the blood by Diffusion
• Sugar and other substances needed by the body do not move

Question 15

How are kidney stones formed?

Answer 15

• High salt and minerals in the diet

- Stones are excreted int he urine

Question 16

How does renal damage/failure occur?

Answer 16

• Kidney isn’t able to filter the blood effectively
• Plasma isn’t reabsorbed properly
• proteins and cells pass through the bow and capsule

Question 17

Advantages of a transplant?

Answer 17

• Patients can lead a more normal life without watching what they eat/drink
• Cheaper for the NHS overall

Question 18

Disadvantages of kidney transplants?

Answer 18

• Kidney only lasts 8-9 years on average
• Must take immune suppressant drugs, which increase the risk of infection
• shortage of organ donors
• any operation carries risk

Question 19

Advantages of dialysis

Answer 19

• Available to all kidney patients (no shortage)

- No need for immune suppressant drugs

Question 20

Disadvantages of dialysis

Answer 20

• Regular dialysis sessions - impacts on patients lifestyle
• Patient must limit their salt and protein intake between dialysis sessions
• Expensive for the NHS