7. How does the body get rid of wastes?


The excretory system is made up of a number of organs in the body that work to remove wastes.

Wastes can be made during the chemical reactions that take place in our cells.

An example of this is the carbon dioxide which is produced during respiration. Respiration uses glucose and oxygen and releases energy. The energy is needed by the cells to do MRS C GREN. However, respiration also produces carbon dioxide which is toxic.

We remove the toxic carbon dioxide from the body when we breathe out.

Our kidneys are organs that get rid of the waste which is travelling around the body in the blood.

The kidneys filter out the wastes and then mixes them with water. This mixture is called urine.

The urine is stored in the bladder until it leaves the body when you urinate.

Your digestive system also removes wastes.

Part of what you eat contains dietary fibre which cannot be digested (broken down). This undigested material makes up half of faeces with the other half being bacteria, both dead and alive. It is good to have a high fibre diet as fibre holds onto water and stops the faeces from getting too dry, leading to you becoming constipated. It also adds bulk to the faeces so it moves more quickly through the large intestine.

Foods high in fibre include vegetables and fruits.


Excrete: To get rid of waste products

Respiration: Process of making energy from glucose.

Kidneys: Organ that filters out waste from the blood and mixes it with water to make urine.

Bladder: Organ that stores urine.

Urine: Liquid waste produced by the kidneys.

Faeces: Solid waste made of undigested material and bacteria.