1. Asthma
5.4 million people in the UK suffer from asthma. Their airways are sensitive to everyday triggers including dust mites, cigarette smoke, pollen and stress.
During an asthma attack, the cells lining the bronchioles release histamines which make the epithelial cells become inflamed and swollen. They also stimulate goblet cells to make extra mucus and the smooth muscle in the walls contract.
As a result, the airways narrow and fill with mucus, making it difficult to breathe.
Drugs can be used to treat asthma – relievers give immediate relief from the symptoms – attaching to cell surface membrane receptors of the smooth muscle cells making them relax and dilate the airways.
Preventers are often steroids which are taken to reduce the sensitivity of the airways.
Explain how the reliever medicines would overcome the symptoms of an asthma attack. (4)
Explain how steroids could reduce the likelihood of an asthma attack. (2)
From green oxford book. P157 answers page 360

2. Peer mark homework exam questions

3. Module 3 Exchange and transport
7.3 Measuring lung capacity

4. Learning Objectives Success Criteria
Understand how to measure lung capacity
To be able to label a spirometer trace
(PSHE LINK:SMOKING, FITNESS, LUNG CAPACITY)
Define the key terms (Grade E - D)
Describe the relationship between vital capacity, tidal volume, breathing rate and oxygen uptake
(Grade C –B)
Analyse and interpret primary and secondary data from a spirometer PAG10
(Grade B – A)

5. Peak flow meter
Starter – Measure your peak flow using a peak flow meter
Measure the peak expiratory flow rate (maximum flow of air that can be forced out of the lungs).
This can show if the airway is blocked in any way.
Used by asthmatics who can check to see if medication is working.
Vitalograph – patient breathes out as quickly as they can and instrument produces a graph, the volume of air is called forced expiratory volume in 1 second
A “normal” value should be between dm3min-1

6. Spirometer and lung volume
Describe how a spirometer can be used to measure vital capacity, tidal volume, breathing rate and oxygen uptake
(Grade C –B)
Spirometer and lung volume
A spirometer consists of a chamber filled with oxygen that floats on water. A person breathes from a mouthpiece attached to a tube connected to the chamber. Breathing in takes in oxygen from the chamber, which then sinks down Breathing out pushes air into the chamber, which then floats up. These movements are recorded using a data logger, so a trace is recorded. Soda lime – absorbs carbon dioxide exhaled, if the level increases dangerously. So the total volume of gas in the spirometer goes down. The volume of carbon dioxide breathed out is the same as the volume of oxygen breathed in, so this reduction can be measured allowing us to work out the total oxygen.
Explain risk assessment check health of volunteer ; oxygen used ; new / sterilised / disinfected mouthpiece (for each volunteer);
idea of: soda lime working ; sufficient oxygen in chamber ; water level not too high

7. Spirometer trace – Label your diagram use page 50 with definitions
Students in pairs to come up to the front to use the spirometer
Define the terms tidal volume and vital capacity
(Grade E - D)

8. Breathing rhythms
As the demands of the body changes so does the pattern and volume of breathing.
The breathing rate is the number of breaths per minute.
Ventilation rate is the total volume of air inhaled on one minute.
Ventilation rate = tidal volume x breathing rate (per minute)
Questions
Normal tidal volume of a male is 500cm3, his ventilation rate is 6dm3 per minute. What is his resting breathing rate?
During exercise his breathing rate goes up to 20 breaths per minute and ventilation rate to 15dm3. What is his new tidal volume?
1) Convert to cm3 first – 6000/500 = 12 breaths/min 2) 15000/20 – 750 cm3

9. Analyse and interpret data from a spirometer
(Grade B – A)
Task
Students to use the spirometer and analyse the data on their trace (nose clip not available – why is this important?)
Answer questions 1-5 on page 51
Self mark answers
Describe how a spirometer can be used to measure vital capacity, tidal volume, breathing rate and oxygen uptake
(Grade C –B)

10. Self assessment Diffusion A) tidal volume – 0.3dm3
Analyse and interpret data from a spirometer
(Grade B – A)
Diffusion
A) tidal volume – 0.3dm3
breaths per minute – 13
B) tidal volume – 1 dm3
breaths per minute – 22
3. 2 dm3min-1
4. Larger tidal volume and more breaths per minute
5. So tidal volume and breathing rate increase
Show of hands - /8

11. Plenary
Jeopardy: Students have to write the question when given the answer.
Tidal volume
Vital capacity
Breathing rate
Soda lime
Spirometer
Inspiration
Expiration