Excretory Products - Kidney, Lungs and Skin

Question 1

What is the waste product of the lungs?

Answer 1

Carbon dioxide.

Question 2

What is the waste product of the skin?

Answer 2

Sweat.

Question 3

What are the waste products of the kidneys?

Answer 3

Urea, which is produced in the liver from excess amino acids.

Water.

Excess ions.

Question 4

Why does selective reabsorption of glucose happen in the proximal convoluted tube?

Answer 4

So that it can be used in respiration.

Question 5

How are cells lining the PCT specialised?

Answer 5

They have folded membranes to increase surface area.

Many mitochondria to provide ATP for active transport.

Question 6

How does urea form?

Answer 6

1) Amino acids are filtered into the liver, along with the rest of the blood via the hepatic artery and hepatic portal vein.

2) Excess amino acids cannot be stored and need to be broken down so they can be excreted. They are broken down into carbohydrates and ammonia.

3) Ammonia is very toxic and must be converted to a slightly less toxic chemical called urea.

4) Amino acids that are needed and urea are released back into the blood stream via the hepatic vein.