The path of air into the lungs, how alveoli are adapted for gas exchange, Fick's law (Edexcel, Biology only), and working with breathing data.
What you will learn
- Name the trachea, bronchi, bronchioles and alveoli in order
- Explain how alveoli are adapted for fast diffusion
- Use Fick's law to compare rates of diffusion (Edexcel, Biology only)
- Calculate percentage changes, means and volumes from breathing data
Into the lungs
Air goes down the trachea (held open by rings of cartilage), into two bronchi, then smaller bronchioles, and ends in millions of tiny air sacs, the alveoli.
Each alveolus is wrapped in capillaries.
Oxygen diffuses from the air in the alveoli into the blood; carbon dioxide diffuses from the blood into the alveoli and is breathed out.
The rest of this lesson and its 13 practice questions are locked.
In this lesson
- Into the lungs
- Built for diffusion
- Fick's law (Edexcel, Biology only)
- Breathing data
- Try it: Volume breathed per minute
13 practice questions, marked as you go; about 20 minutes in all.
Key terms
Trachea, Bronchi, Bronchioles, Alveoli, Compare, Bottom
In this unit: Organisation: tissues, organs, digestion and circulation
Levels of organisation, digestion and enzymes with the amylase and food test practicals, the heart, blood and lungs, heart disease and cancer, and transport in plants.
- Organisation, digestion and enzymes
- Enzyme activity and the food tests
- The heart, blood vessels and blood
- The lungs and gas exchange
- Heart disease, risk factors and cancer
- Plant tissues and transport
- Health, lifestyle and body measurements
- Cancer: tumours, risk factors and data
All of Organisation: tissues, organs, digestion and circulation