11 Gas Exchange in Humans
(Core / Extended)

11.1 Gas Exchange in Humans
What you need to know:

1.  Describe the features of gas exchange surfaces in humans, limited to: large surface area, thin surface, good blood supply and good ventilation with air
2. Identify in diagrams and images the following parts of the breathing system: lungs, diaphragm, ribs, intercostal muscles, larynx, trachea, bronchi, bronchioles, alveoli and associated capillaries
3. Identify in diagrams and images the internal and external intercostal muscles
4. State the function of cartilage in the trachea
5. Explain the role of the ribs, the internal and external intercostal muscles and the diaphragm in producing volume and pressure changes in the thorax leading to the ventilation of the lungs
6. Investigate the differences in composition between inspired and expired air using limewater as a test for carbon dioxide
7. Explain the differences in composition between inspired and expired air
8. Describe the differences in composition between inspired and expired air, limited to: oxygen, carbon dioxide and water vapour
9. Investigate and describe the effects of physical activity on the rate and depth of breathing
10. Explain the link between physical activity and the rate and depth of breathing in terms of: an increased carbon dioxide concentration in the blood, which is detected by the brain, leading to an increased rate and greater depth of breathing
11. Explain the role of goblet cells, mucus and ciliated cells in protecting the breathing system from pathogens and particles 

Videos: Gas exchange in humans - overview

Videos: Alveoli Gas Exchange Investigation

Videos: Lungs and Ventilation

Videos: Goblet Cells (11.1.111)

Videos: Knowthe Differences: Gas Exchange, Breathing and Respirations

EXAMPLE QUESTIONS

Videos: 6 marks gas exchange question

Videos: Gas exchange and breathing mechanism

Videos: Excellent discussion....end of chapter and past exam questions... watch patiently!