Revision: Using the spirometer and regulating the heart rate and breathing rate

Starter: Copy the diagram and fill in the boxed out labels.

Missing terms:• Tidal volume• Inspiratory reserve

volume• Expiratory reserve

volume• Vital capacity• Residual volume• Total lung capacity• Inspiratory capacity

Specification outcomes

• Describe how to investigate the effects of exercise on tidal volume and breathing rate using data from spirometer traces.

• Why is soda lime use to absorb the CO2 ?

Full animation at: http://athome.harvard.edu/programs/hse/video/hse2_5_module.html

Using a spirometer

CO2 levels affect the breathing rate and therefore, if carbon dioxide was allowed to accumulate, the

investigation would be affected.

Spirograph terms

• Define:– Tidal volume– Inspiratory reserve volume– Expiratory reserve volume– Vital capacity– Residual volume– Total lung capacity– Inspiratory capacity

Spirographs

Spirographs

Specification outcomes

• Explain the principle of negative feedback in maintaining systems within narrow limits.

• Explain how the heart rate and ventilation rate are controlled and the roles of the cardiovascular control centre and the ventilation centre.

• Explain how variations in ventilation and cardiac output enable rapid delivery of oxygen to tissues and the removal of carbon dioxide from them.

Name Location Function / Response

Baroreceptors

Chemoreceptors

Stretch receptors

Respiratory centre / ventilation centre

Name Location Function / Response

Baroreceptors Carotid arteries

Chemoreceptors

Stretch receptors

Respiratory centre / ventilation centre

Name Location Function / Response

Baroreceptors Carotid arteries

Senses blood pressure changes during and after exercise due to changing blood vessel diameter – increased blood pressure causes medulla oblongata to send signals down parasympathetic nerve

Chemoreceptors

Stretch receptors

Respiratory centre / ventilation centre

Name Location Function / Response

Baroreceptors Carotid arteries

Senses blood pressure changes during and after exercise due to changing blood vessel diameter – increased blood pressure causes medulla oblongata to send signals down parasympathetic nerve

Chemoreceptors Medulla, carotid arteries, aorta

Stretch receptors

Respiratory centre / ventilation centre

Name Location Function / Response

Baroreceptors Carotid arteries

Senses blood pressure changes during and after exercise due to changing blood vessel diameter – increased blood pressure causes medulla oblongata to send signals down parasympathetic nerve

Chemoreceptors Medulla, carotid arteries, aorta

Senses level of CO2 and pH of blood

Stretch receptors

Respiratory centre / ventilation centre

Name Location Function / Response

Baroreceptors Carotid arteries

Senses blood pressure changes during and after exercise due to changing blood vessel diameter – increased blood pressure causes medulla oblongata to send signals down parasympathetic nerve

Chemoreceptors Medulla, carotid arteries, aorta

Senses level of CO2 and pH of blood

Stretch receptors Bronchi or heart muscle

Respiratory centre / ventilation centre

Name Location Function / Response

Baroreceptors Carotid arteries

Senses blood pressure changes during and after exercise due to changing blood vessel diameter – increased blood pressure causes medulla oblongata to send signals down parasympathetic nerve

Chemoreceptors Medulla, carotid arteries, aorta

Senses level of CO2 and pH of blood

Stretch receptors Bronchi or heart muscle

In bronchi, inhalation stimulates stretch receptors which inhibits muscles and exhalation occurs.In heart, increased return of blood due to exercise stretches heart muscle and stimulates medulla oblongata

Respiratory centre / ventilation centre

Name Location Function / Response

Baroreceptors Carotid arteries

Senses blood pressure changes during and after exercise due to changing blood vessel diameter – increased blood pressure causes medulla oblongata to send signals down parasympathetic nerve

Chemoreceptors Medulla, carotid arteries, aorta

Senses level of CO2 and pH of blood

Stretch receptors Bronchi or heart muscle

In bronchi, inhalation stimulates stretch receptors which inhibits muscles and exhalation occurs.In heart, increased return of blood due to exercise stretches heart muscle and stimulates medulla oblongata

Respiratory centre / ventilation centre

Medulla

Name Location Function / Response

Baroreceptors Carotid arteries

Senses blood pressure changes during and after exercise due to changing blood vessel diameter – increased blood pressure causes medulla oblongata to send signals down parasympathetic nerve

Chemoreceptors Medulla, carotid arteries, aorta

Senses level of CO2 and pH of blood

Stretch receptors Bronchi or heart muscle

In bronchi, inhalation stimulates stretch receptors which inhibits muscles and exhalation occurs.In heart, increased return of blood due to exercise stretches heart muscle and stimulates medulla oblongata

Respiratory centre / ventilation centre

Medulla Controls breathing rate

1. What are the names of main areas which regulate the breathing rate and body temperature?

2. Where are they found?

• Respiratory centre / ventilation centre in medulla

• Heat gain centre and heat loss centre in hypothalamus

How is the heart rate controlled?

Describe the roles of the following:

1. The cardiovascular control centre

2. Sympathetic nervous system

3. Parasympathetic nervous system

4. Stretch receptors

5. Baroreceptors

How is the ventilation rate is controlled?

1. Combine fig. 7.3.9 on p. 159 and fig. 7.3.10 on p. 160 into one diagram including both stretch receptors and chemoreceptors.

2. Explain the roles of the:a) medullab) respiratory centre / ventilation centrec) Chemoreceptorsd) Carotid bodiese) Aortic bodies

• https://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter21/animation__baroreceptor_reflex_control_of_blood_pressure.html