Biology
Understanding the human digestive system
We are learning how to: • Identify the organs of the human digestive system. • Explain the role of digestion. • Analyse links between digestion and the circulatory system.
The food we eat has chemical energy stored in it. To make use of this energy, we must digest the food. Digestion starts at the mouth and finishes at the anus. Many organs of the body are involved in digesting our food along the way. The human digestive system
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Food is broken down and passes through each of the organs in the digestive system. 1. List the organs of the digestive system in the order that food passes through. 2. Suggest what would happen if there were a blockage in the large intestine. FIGURE 1.2.7a: Digestion of your food starts in your mouth. mouth Physical and chemical digestion (by saliva)
teeth tongue
gullet
stomach
Physical and chemical digestion
small intestine
Chemical digestion
pancreas
large intestine
appendix FIGURE 1.2.7b: Trace the journey of food through the digestive system.
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anus
KS3 Science Book 1: Eating, Drinking and Breathing
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