Human body system (digestive, respiratory,circulatory

• Systems


  • Respiratory
  • Circulatory
  • Muscular
  • Digestive
• Digestive System


  Parts that digest food: Mouth, Teeth, Stomach, Small intestines
• Digestion in the mouth

  1. Chew and grind food into smaller pieces

  2. Increases surface area exposed to digestive juices

  3. Speeds up digestion process
• Saliva


  • Contains digestive juices
  • Softens and moistens the food
• Tongue


  • Rolls the food into a ball
  • Enables the food to be swallowed easily
• Gullet


  • Has muscles that help push food down into the stomach
  • No digestion occurs here
• Stomach


  • Contains digestive juices
  • Churns the food into smaller pieces
• Small intestine

  • Contains digestive juices
  • Most digestion occurs here
  • Digested food is absorbed into the bloodstream
• Large intestine


  • Absorbs water and mineral salts from undigested food
  • Passes out waste material from the body
• Respiratory System


  • Nose allows air in and out
  • Nose hairs trap dust
  • Windpipe transfers air to lungs
  • Lungs contain air sacs for gaseous exchange
  • Diaphragm contracts and relaxes to control breathing
• Breathing rate increases when we exercise

  Body needs more oxygen for respiration
• The respiratory, digestive and circulatory systems work together