Breathing and Exchange of Gases quiz

The normal tidal volume of a healthy human is about:

Gas exchange in humans takes place in the:

The respiratory rhythm centre is located in the:

Most carbon dioxide is transported in blood as:

The partial pressure of oxygen in alveolar air is about:

Insects breathe through:

Inspiration occurs when the diaphragm:

The solubility of carbon dioxide in blood compared to oxygen is about:

Which of these is an occupational respiratory disorder?

The volume of air left in the lungs after a forceful expiration is the:

What are the steps involved in respiration? (2 marks)

Distinguish between inspiratory capacity and functional residual capacity. (2 marks)

How does high pCO2 in tissues favour the release of oxygen? (2 marks)

What is the role of carbonic anhydrase in carbon dioxide transport? (2 marks)

Why is the diffusion membrane in the alveoli well suited for gas exchange? (2 marks)

What is the role of the chemosensitive area of the medulla? (2 marks)

What is asthma? (2 marks)

Why do people working in stone-grinding industries suffer from respiratory disorders? (2 marks)

Why is normal expiration passive? (2 marks)

Explain the role of the epiglottis in breathing. (2 marks)

A person's vital capacity is 4,200 mL. If the tidal volume is 500 mL and the expiratory reserve volume is 1,100 mL, calculate the inspiratory reserve volume. (3 marks)

Atmospheric air has a pO2 of 159 mm Hg and a pCO2 of 0.3 mm Hg. Calculate how many times greater the atmospheric pO2 is than the pO2 in the tissues (40 mm Hg). (3 marks)

About 97% of oxygen is carried by RBCs and 3% dissolved in plasma. If 250 mL of oxygen is used per minute, calculate the volume carried each way. (3 marks)

A person's total lung capacity is 6,000 mL and residual volume 1,200 mL. Calculate the vital capacity. (3 marks)

A diver breathes 12 times per minute with a tidal volume of 600 mL. Calculate the air needed for a 40-minute dive in litres. (3 marks)

Read the passage and answer the questions. A student blew into a spirometer. Her tidal volume was 500 mL. After normal inspiration she inhaled forcibly an extra 2,800 mL. After normal expiration she exhaled forcibly 1,000 mL more. (i) Calculate her vital capacity. (ii) What is the extra 2,800 mL called? (iii) Why is the vital capacity higher in athletes? (5 marks)

Read the passage and answer the questions. Oxygen can bind with haemoglobin in a reversible manner to form oxyhaemoglobin. Each haemoglobin molecule can carry a maximum of four molecules of oxygen. Binding of oxygen with haemoglobin is primarily related to the partial pressure of oxygen. Partial pressure of carbon dioxide, hydrogen ion concentration and temperature are the other factors that can interfere with this binding. (i) What conditions favour formation of oxyhaemoglobin in the alveoli? (ii) What conditions favour its dissociation in the tissues? (iii) What does the sigmoid curve show? (5 marks)

Read the passage and answer the questions. Human beings have a significant ability to maintain and moderate the respiratory rhythm to suit the demands of the body tissues. This is done by the neural system. A specialised centre present in the medulla region of the brain called the respiratory rhythm centre is primarily responsible for this regulation. (i) Name the centre in the pons that moderates the rhythm. (ii) How does a rise in carbon dioxide affect breathing? (iii) What is the role of receptors in the aortic arch and carotid artery? (5 marks)

Read the passage and answer the questions. A worker in a stone-quarry developed a persistent cough and breathlessness. Doctors found that his lungs had become fibrotic due to long exposure to dust. He had never smoked. (i) Name the disorder. (ii) Why does the dust damage the lungs? (iii) Suggest two preventive measures. (5 marks)

Read the passage and answer the questions. Emphysema is a chronic disorder in which alveolar walls are damaged, due to which the respiratory surface is decreased. One of the major causes of this is cigarette smoking. Asthma is a difficulty in breathing causing wheezing due to inflammation of bronchi and bronchioles. (i) Why does emphysema reduce gas exchange? (ii) What happens to the bronchi in asthma? (iii) Give two effects of smoking on the respiratory system. (5 marks)

Describe the human respiratory system with a labelled diagram. Explain the role of each part. (6 marks)

Explain the mechanism of breathing with labelled diagrams of inspiration and expiration. (6 marks)

Explain the respiratory volumes and capacities. How are they measured? What is their significance? (6 marks)

Describe the exchange of gases in the alveoli and tissues. Explain the factors affecting diffusion with a diagram showing partial pressures. (6 marks)

Explain the transport of oxygen and carbon dioxide in blood. Draw the oxygen dissociation curve. (6 marks)