Excretory System

Question 1

What is excretion

Answer 1

Excretion is the process of removing waste products from the body.

Question 2

What are the waste products of excretion

Answer 2

These wastes include CO2, nitrogenous waste (urea), salt and water

Question 3

Describe excretion in the lungs

Answer 3

Carbon dioxide (CO2) is a waste product produced by cellular respiration.
If CO2 is not removed from the body, it can change the pH of the blood and make it acidic.
This means it is the level of CO2 in your blood that will influence your breathing rate, as it is important that it is removed efficiently from the body.

Question 4

Describe excretion in the kidneys

Answer 4

The kidneys are part of the urinary system and play an important role in filtering wastes from the blood.
Each kidney contains 1 million nephrons, the tiny structures that filter waste like urea, salts and water out of the blood and create urine.
Urine passes from the kidneys, down the ureters into the bladder
The kidneys also play an important role in regulating the water balance of the body

Question 5

Describe excretion from the skin

Answer 5

Excretion occurs indirectly through the skin when we sweat.
Sweat will remove some water, salts and small amounts of urea from the body.

Question 6

Describe the water balance in the body

Answer 6

The volume of water in the body needs to be regulated as it influences the concentration of the blood and other substances in it.