The Respiratory System

What The Respiratory System covers

The Respiratory System is examined in Component 01, Physiological factors affecting performance. It covers breathing frequency, tidal volume and minute ventilation, mechanics of breathing at rest and in exercise, Regulation of breathing and gas exchange at the alveoli and the muscles.

The 4 subtopics

Each one has its own page.

• Breathing frequency, tidal volume and minute ventilationBreathing frequency, tidal volume and minute ventilation at rest, the minute ventilation equation with worked examples, the tidal volume plateau, and minute ventilation before, during and after submaximal and maximal exercise.Open →
• Mechanics of breathing at rest and in exerciseThe diaphragm and external intercostals in inspiration, passive expiration at rest, the sternocleidomastoid and pectoralis minor in exercise, active expiration with the internal intercostals and rectus abdominis, and breathing in recovery.Open →
• Regulation of breathingThe respiratory control centre and its inspiratory and expiratory centres, the phrenic and intercostal nerves, chemical control by chemoreceptors and carbon dioxide, neural control by proprioceptors, thermoreceptors and lung stretch receptors, and breath-holding.Open →
• Gas exchange at the alveoli and the musclesPartial pressure and pressure gradients at the alveoli and the muscles, alveolar structure, myoglobin, the arterio-venous oxygen difference, the oxyhaemoglobin dissociation curve and the Bohr shift in exercise and recovery.Open →

What you need to know

Answer each one before you reveal it.

Take The Respiratory System further

The same content, four other ways.

Commonly confused

Pairs that lose marks when they are blurred together.

• Tidal volume vs Minute ventilation

  Tidal volume: the amount of air moved in or out of the lungs per breath. Minute ventilation: the amount of air moved in or out of the lungs every sixty seconds.

• Inspiration vs Expiration

  Inspiration: the drawing of air into the lungs. Expiration: the movement of air out of the lungs.

• External intercostals vs Internal intercostals

  External intercostals: rib muscles that lift the ribs up and out to draw air in. Internal intercostals: rib muscles that pull the ribs down and in to force air out.

Questions from this topic

Each one with the model answer underneath.

1. 1

   Define breathing frequency and give a typical resting value.

   Model answer

   Breathing frequency is the number of breaths taken per minute. A typical resting value is 12–15 breaths per minute.

2. 2

   Define tidal volume and give a typical resting value.

   Model answer

   Tidal volume is the volume of air breathed in or out per breath. A typical resting value is about 0.5 litres.

3. 3

   Define minute ventilation and give a typical resting value.

   Model answer

   Minute ventilation is the volume of air breathed in or out per minute. A typical resting value is about 6–7.5 litres per minute.

4. 4

   State the equation for minute ventilation.

   Model answer

   Minute ventilation equals tidal volume multiplied by breathing frequency. The equation is VE = TV × f.

5. 5

   A performer at rest has a tidal volume of 0.5 L and a breathing frequency of 14 breaths per minute. What is the minute ventilation?

   Model answer

   The minute ventilation is 7 L/min. Tidal volume × frequency = 0.5 L × 14 = 7.0 L/min.

6. 6

   A resting minute ventilation of 6 L/min comes from 12 breaths per minute. What is the tidal volume?

   Model answer

   The tidal volume is 0.5 L, or 500 ml. Minute ventilation ÷ frequency = 6 L/min ÷ 12 = 0.5 L.

What is inside Levo

Six ways to work the same material.

The Respiratory System revision questions

What does The Respiratory System cover in OCR A-Level Physical Education?

4 subtopics: breathing frequency, tidal volume and minute ventilation, mechanics of breathing at rest and in exercise, regulation of breathing and gas exchange at the alveoli and the muscles. Each one has its own page with questions and model answers.

How is The Respiratory System organised?

By the OCR H555 specification, subtopic by subtopic, so it matches the order you are taught it in.