Kidneys

Question 1

What are the functions of the kidneys?

Answer 1

• Regulate water levels
• Regulate ion levels
• Remove Urea

Question 2

Deamination

Answer 2

1. If the body has more amino acids than it needs, it can convert them into lipids or carbohydrates, which can be stored as an energy source for later.
2. This process is known as deamination, and takes place in the liver.
3. The downside of this process is that it produces the waste product urea, which has to be excreted by the kidney

Question 3

How are ions removed from the body?

Answer 3

• By the kidneys
• By sweating

Question 4

Ions in the bloodstream

Answer 4

If concentration of ions gets too high or too low in the bloodstream, it can damage cells and make us ill

Question 5

What happens to cells if there is too much water in the body?

Answer 5

They expand due to intake of water through osmosis and burst

Question 6

Nephrons

Answer 6

Millions of tiny units within the kidneys, consist of tubules and capillaries

Question 7

Filtration (ultrafiltration)

Answer 7

As blood passes through the kidneys, small substances like glucose, amino acids, and water, are absorbed from the blood into the kidneys.

Question 8

Selective reabsorption

Answer 8

As the filtrate passes through the kidneys, useful substances like glucose are reabsorbed from the tubules, into the blood.

Question 9

Substances that cannot pass into the kidney tubules

Answer 9

• Large proteins
• Red blood cells

This is because they are too large to pass from the glomerelus to the Bowman’s capsule.

Question 10

Antidiuretic hormone (ADH)

Answer 10

Hormone responsible for regulation of water levels in the body

Question 11

Hypothalamus

Answer 11

Part of the brain that detects the level of water in the body

Question 12

How the body responds to low water levels

Answer 12

1. A part of the brain called the hypothalamus detects the low concentration of water in the bloodstream.
2. This causes it to send a signal to the pituitary gland, which tells it to release more antidiuretic hormone (ADH).
3. The ADH travels around the body in the blood, and stimulates the kidneys to reabsorb more water from the tubules into the blood.
4. This means that less urine will be made, and the concentration of water in the blood rises.

Question 13

Effect of ADH

Answer 13

Increases water concentration in the bloodstream

Question 14

What type of feedback does the body use to regulate water levels?

Answer 14

Negative feedback