1. Past Exam Question Remember this was an A4 sheet! So your answer should be approx half!

2. Lung volume increases Ventilation - Inspiration External intercostals contract Internal intercostals relax Ribs pulled up and out Diaphragm flattens Atmospheric pressure greater Lung pressure less INSPIRATION – air forced into lungs

3. Lung volume decreases Ventilation - Expiration Internal intercostals contract External intercostals relax Ribs move down and in Diaphragm relaxes into ‘dome’ Lung pressure greater Atmospheric pressure less EXPIRATION – air forced out of lungs

4. Label the Lungs

5. Bacteria inhaled by person not immune to it Bacteria start to reproduce in upper lung where plenty of oxygen Immune system responds, phagocytes arrive and ingest bacteria Lymph nodes that drain area of lungs become inflammed and enlarged – Few symptoms and the infection is controlled, but some bacteria remain Many years later bacteria re-emerge in a second infection More difficult to control. Lung tissue damaged, scar tissue forms Lung tissue and blood coughed up,without treatment can fatally spread throughout body Primary Infection Post-Primary Infection (may not happen) Usually in young children In healthy, more resistant people Tuberculosis

6. Lung Structure StructureFeatures Trachea Supported by c-shaped rings of cartilage Lined with cilliated epithelial cells to sweep mucus up to throat Goblet cells produce mucus to trap dirt & microbes Bronchi Larger branches supported by cartilage, less in smaller Lined with cilliated epithelial cells to sweep mucus up to throat Goblet cells produce mucus to trap dirt & microbes Bronchioles Walls are made of muscle and epithelial cells Muscle allows them to constrict to control air flow to alveoli Alveoli Tiny air sacs (100-300μm in diameter) Lined with epithelial cells Membrane is gas exchange surface Contain collagen and elastic fibres (stretch and spring back)

7. TB Exam Question

8. (b) After 4 minutes of exercise, the breathing rate was 20 breaths per minute. Explain how you could use this information and the graph to calculate tidal volume. (c) When a person starts to breathe out, the percentage of oxygen in the air first exhaled is the same as the percentage of oxygen in the atmospheric air. Explain why.

9. Answers (a)Immediate/rapid increase, steady rise and plateau clearly identified; Ignore references to rest period if clearly identified as such1 (b)Find value of pulmonary ventilation from graph / 26-28; Divide by breathing rate/20;2 (c)Air is from nose/trachea/bronchi/not been in alveoli/dead space; Gas exchange/diffusion only in alveoli / not in these structures;2