7.2

Digestive system

Cambridge IGCSE Biology (0610)  · Unit 7: Human nutrition  · 13 flashcards

Digestive system is topic 7.2 in the Cambridge IGCSE Biology (0610) syllabus , positioned in Unit 7 — Human nutrition , alongside Diet, Physical digestion and Chemical digestion.  In one line: Ingestion is the process of taking substances, such as food and drink, into the body via the mouth.

This topic is examined in Paper 1 (multiple-choice) and Papers 3/4 (theory), plus Paper 5 or Paper 6 (practical / alternative to practical). Past papers from 2022 to 2025 show this topic across 15 questions worth 197 marks (around 2.9% of all Biology marks in those years).

The deck below contains 13 flashcards — 5 definitions, 6 key concepts and 2 identification cards — covering the precise wording mark schemes reward.  Use the 5 definition cards to lock down command-word answers (define, state), then move on to the concept and application cards to handle explain, describe and compare questions.

Key definition

Ingestion

Ingestion is the process of taking substances, such as food and drink, into the body via the mouth.

Example: A human eating an apple involves ingestion.

What the Cambridge 0610 syllabus says

Official 2026-2028 spec

These are the exact learning objectives Cambridge sets for this topic. Match the command word (Describe, Explain, State, etc.) in your answer to score full marks.

  1. Identify Identify in diagrams and images the main organs of the digestive system, limited to: (a) alimentary canal: mouth, oesophagus, stomach, small intestine (duodenum and ileum) and large intestine (colon, rectum, anus) (b) associated organs: salivary glands, pancreas, liver and gall bladder
  2. Describe Describe the functions of the organs of the digestive system listed in 7.2.1, in relation to: (a) ingestion – the taking of substances, e.g. food and drink, into the body (b) digestion – the breakdown of food (c) absorption – the movement of nutrients from the intestines into the blood (d) assimilation – uptake and use of nutrients by cells (e) egestion – the removal of undigested food from the body as faeces
Key Concept Flip

Name the organs forming the alimentary canal.

Answer Flip

The alimentary canal consists of the mouth, oesophagus, stomach, small intestine (duodenum and ileum), large intestine (colon, rectum), and anus. Food passes directly through these organs during digestion and egestion.

Key Concept Flip

Name the accessory organs of the digestive system.

Answer Flip

The accessory organs include the salivary glands, pancreas, liver, and gall bladder. These organs aid digestion by secreting enzymes or other substances into the alimentary canal; food doesn't pass directly through them.

Definition Flip

What is ingestion?

Answer Flip

Ingestion is the process of taking substances, such as food and drink, into the body via the mouth.

Example: A human eating an apple involves ingestion.
Definition Flip

What is digestion?

Answer Flip

Digestion is the breakdown of large, insoluble food molecules into smaller, soluble molecules that can be absorbed. This involves both mechanical digestion (

Example: chewing) and chemical digestion (. enzyme action).
Key Concept Flip

What is the role of the mouth in digestion?

Answer Flip

The mouth is where ingestion and mechanical digestion (chewing) begin, and chemical digestion of carbohydrates starts with salivary amylase enzyme breaking down starch into maltose.

Key Concept Flip

What is the function of the oesophagus?

Answer Flip

The oesophagus transports food from the mouth to the stomach via peristalsis, which are wave-like muscle contractions that push the bolus down. No digestion or absorption occurs here.

Key Concept Flip

What is the role of the stomach in digestion?

Answer Flip

The stomach stores and mixes food with gastric juice, which contains hydrochloric acid (kills bacteria, optimum pH for enzymes) and pepsin (enzyme that starts protein digestion). Mechanical digestion also occurs through churning.

Key Concept Flip

What is the function of the duodenum?

Answer Flip

The duodenum is the first part of the small intestine where digestive enzymes from the pancreas and bile from the liver mix with the chyme. It continues the digestion of carbohydrates, proteins, and lipids.

Key Concept Flip

What is the role of the ileum?

Answer Flip

The ileum is the last part of the small intestine where the absorption of digested food molecules occurs into the bloodstream. It has villi and microvilli to increase the surface area for absorption.

Key Concept Flip

What is the function of the large intestine (colon and rectum)?

Answer Flip

The colon absorbs water and salts from undigested food, while the rectum stores faeces until egestion. The large intestine does not produce digestive enzymes.

Definition Flip

What is absorption?

Answer Flip

Absorption is the movement of digested food molecules and ions through the wall of the intestine into the blood or lymph.

Example: glucose is absorbed into the blood from the ileum.
Definition Flip

What is assimilation?

Answer Flip

Assimilation is the process by which cells use absorbed nutrients to build new protoplasm, or to provide energy.

Example: amino acids can be assimilated to synthesize proteins in muscle cells.
Definition Flip

What is egestion?

Answer Flip

Egestion is the removal of undigested waste materials from the body as faeces, through the anus. Faeces consist of undigested food, dead cells and bacteria.

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7.1 Diet 7.3 Physical digestion

Key Questions: Digestive system

What is ingestion?

Ingestion is the process of taking substances, such as food and drink, into the body via the mouth.

Example: A human eating an apple involves ingestion.
What is digestion?

Digestion is the breakdown of large, insoluble food molecules into smaller, soluble molecules that can be absorbed. This involves both mechanical digestion (

Example: chewing) and chemical digestion (. enzyme action).
What is absorption?

Absorption is the movement of digested food molecules and ions through the wall of the intestine into the blood or lymph.

Example: glucose is absorbed into the blood from the ileum.
What is assimilation?

Assimilation is the process by which cells use absorbed nutrients to build new protoplasm, or to provide energy.

Example: amino acids can be assimilated to synthesize proteins in muscle cells.
What is egestion?

Egestion is the removal of undigested waste materials from the body as faeces, through the anus. Faeces consist of undigested food, dead cells and bacteria.

Tips to avoid common mistakes in Digestive system

More topics in Unit 7 — Human nutrition

Digestive system sits alongside these Biology decks in the same syllabus unit. Each uses the same spaced-repetition system, so progress in one informs the next.

Cambridge syllabus keywords to use in your answers

These are the official Cambridge 0610 terms tagged to this section. Mark schemes credit responses that use the exact term — weave them into your answers verbatim rather than paraphrasing.

digestion alimentary canal mouth oesophagus stomach small intestine large intestine rectum anus liver pancreas gall bladder salivary gland bile enzyme peristalsis absorption egestion ingestion

Key terms covered in this Digestive system deck

Every term below is defined in the flashcards above. Use the list as a quick recall test before your exam — if you can't define one of these in your own words, flip back to that card.

Ingestion
Digestion
Absorption
Assimilation
Egestion

Related Biology guides

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