Digestive System Pathway

Name:

Date:

Part 1: Follow the Pathway

1. Label the digestive system. Draw a simple digestive-system pathway in the box. Label each structure using the prompts below. Include arrows to show the direction food travels.

Labels to include: mouth, oesophagus, stomach, small intestine, large intestine, rectum/anus, liver and pancreas.

2. Sequence the pathway. Number these stages from 1 (first) to 7 (last).

____ Large intestine ____ Mouth ____ Rectum/anus

____ Oesophagus ____ Small intestine ____ Stomach ____ Egestion

3. Which two organs add digestive juices to the small intestine?

Liver and pancreas

Mouth and oesophagus

Stomach and large intestine

4. Match each organ with its main function.

A. Stomach

B. Small intestine

C. Large intestine

D. Liver

E. Pancreas

F. Rectum/anus

1. Stores faeces and controls egestion

2. Produces bile and processes absorbed nutrients

3. Absorbs most digested nutrients into the blood

4. Mixes food and begins protein digestion

5. Absorbs water and forms faeces

6. Releases digestive enzymes into the small intestine

Write the correct number beside each letter: A ____ B ____ C ____ D ____ E ____ F ____

Part 2: Digestion and Absorption

5. Explain the difference between mechanical digestion and chemical digestion. Give one example of each.

6. What is the role of enzymes in digestion?

7. Explain how villi help the small intestine absorb nutrients.

8. Application: A student eats a meal rich in carbohydrates, such as rice, bread and fruit. Explain what happens to the carbohydrates from the mouth until they are used by body cells. Include the words enzyme, small intestine and glucose.

Key Vocabulary and Answers

Vocabulary: ingestion – taking food into the mouth; digestion – breaking food into smaller substances; enzyme – a protein that speeds up a chemical reaction; absorption – movement of nutrients into the blood; villi – tiny finger-like structures that increase the small intestine’s surface area; egestion – removal of faeces from the body.

Answer Key

1. Labels should show the mouth, oesophagus, stomach, small intestine, large intestine, rectum/anus, liver and pancreas. Arrows should show food moving from the mouth towards the anus.

2. Mouth 1, oesophagus 2, stomach 3, small intestine 4, large intestine 5, rectum/anus 6, egestion 7.

3. Liver and pancreas.

4. A–4, B–3, C–5, D–2, E–6, F–1.

5. Mechanical digestion physically breaks food into smaller pieces, for example chewing. Chemical digestion uses enzymes and digestive juices to break large food molecules into smaller soluble molecules.

6. Enzymes speed up chemical digestion by breaking large food molecules into smaller molecules that can be absorbed.

7. Villi provide a large surface area and have a thin surface with blood vessels, allowing digested nutrients to pass quickly into the blood.

8. Carbohydrates are mechanically broken up by chewing. Enzymes begin chemical digestion in the mouth and continue in the small intestine, where carbohydrates are broken down into glucose. Glucose is absorbed through the villi into the blood and transported to cells for energy, growth and repair.