Watch the 2 videos below to learn more about our body systems.

Respiratory & Circulatory Systems:


digestive System:


Key concepts of our body systems:

Respiratory system

  • Our respiratory system consists of the nose, windpipe and lungs.

  • We take in oxygen for the body and give out carbon dioxide from the body.

  • When we inhale (breathe in), our rib cage moves out and up. Our diaphragm moves down. As a result, our lungs expand.

  • When we exhale (breathe out), our rib cage moves in and down. Our diaphragm moves up. As a result, our lungs contract.


Circulatory system

  • Our circulatory system consists of the heart, blood and blood vessels.

  • It transports oxygen, digested food and water to the cells in the body.

  • It transports carbon dioxide and other waste materials away from all parts of the body.

  • The heart pumps blood around the body.

  • Blood carries substances around the body.

  • Blood travels inside blood vessels.


Digestive system

  • Our digestive system breaks down food into simpler substances.

  • Digested food and water is absorbed into the circulatory system (blood stream) so that they can be used by the body.


  • Teeth chew and break up food into smaller pieces.

  • Digestive juices in the saliva break down food into simpler substances.


  • It is a muscular tube that pushes food from the mouth to the stomach.


  • It is a muscular organ that mixes the food up with the digestive juices.
  • Digestive juices break down food into simpler substances.

Small intestine

  • Digestive juices break down food into simpler substances.

  • Most digestion occurs in the small intestine. Digestion is completed in this organ.

  • Digested food is absorbed into the bloodstream of the circulatory system.

Large intestine

  • No food is digested after it enters the large intestine.

  • Water (and mineral salts) is absorbed from the undigested food into the bloodstream of the circulatory system.

Rectum and Anus

  • The undigested food is stored in the rectum before it is passed out as faeces through the anus.


Skeletal and Muscular system

  • Our skeletal system is made up of bones such as the skull, rib cage and backbone.

  • It supports the body and gives the body shape.

  • It protects organs like the brain, lungs and heart.

  • The skeletal system works together with the muscular system to help us move.


Take this quiz to recap what you have learnt. Aim to reach the moon!