OrganisationVery High Exam FrequencyAQAEdexcelOCRWJEC

Gas Exchange in Humans

Lung structure, alveoli adaptations, breathing mechanism, gas transport in blood, and effects of smoking

What you'll cover

  • Respiratory system structure: trachea, bronchi, bronchioles, alveoli
  • Alveoli adaptations: large surface area, thin walls, rich blood supply
  • Breathing mechanism: diaphragm and intercostal muscles
  • Inspiration and expiration processes
  • Gas exchange by diffusion in alveoli
  • Oxygen transport by hemoglobin
  • Carbon dioxide transport in plasma
  • Control of breathing rate
  • Effects of exercise on breathing
  • Smoking damage: emphysema, lung cancer
  • Asthma and respiratory diseases

Sample Flashcards

What are alveoli?
Tiny air sacs in the lungs where gas exchange takes place - oxygen enters the blood and carbon dioxide leaves
What is the trachea?
The main airway (windpipe) that carries air from the throat to the lungs, reinforced with cartilage rings

Sample Questions

Which is the correct order of structures air passes through to reach the lungs?

  • A. Trachea → bronchi → bronchioles → alveoli
  • B. Bronchi → trachea → bronchioles → alveoli
  • C. Trachea → bronchioles → bronchi → alveoli
  • D. Bronchioles → bronchi → trachea → alveoli
1 markfoundation

Explain how the structure of alveoli is adapted for efficient gas exchange.

4 marksstandard

19

exam-style questions

23

revision flashcards

Ready to revise Gas Exchange in Humans?

Get personalised daily study plans, adaptive quizzes, and spaced repetition flashcards.

Join Alpha