Question 1: Define the term 'ventilation' in the context of the respiratory system.

Answer: Ventilation is the process of moving air into and out of the lungs.

Question 2: Describe the role of the diaphragm during inhalation and exhalation.

Answer: During inhalation, the diaphragm contracts and moves downward to increase thoracic volume; during exhalation, it relaxes and moves upward to decrease thoracic volume.

Question 3: Explain how the intercostal muscles assist in breathing.

Answer: Intercostal muscles help expand and contract the rib cage, aiding in lung ventilation during breathing.

Question 4: What is the function of the alveoli in the lungs?

Answer: Alveoli are tiny air sacs where gas exchange occurs between oxygen and carbon dioxide.

Question 1: Calculate the minute ventilation rate if a person breathes 15 times per minute with a tidal volume of 0.5 litres per breath. Use the formula: Ventilation rate = Breaths per minute × Tidal volume (litres).

Answer: 7.5 litres per minute

Question 2: A spirometer measures a lung capacity of 4.8 litres. If a person's tidal volume is 0.6 litres, how many breaths would they take to utilise their full lung capacity?

Answer: 8 breaths

Question 1: Describe a simple method to measure an individual's respiratory rate.

Answer: Count the number of breaths taken in one minute by observing chest movements.

Question 2: Identify two variables that should be controlled during an experiment measuring lung capacity.

Answer: Age and physical activity level of the participant.

Question 3: List two safety precautions that must be taken when using a spirometer.

Answer: Ensure the spirometer is clean to prevent infection; avoid overexertion that could cause dizziness.

Question 1: A student records their breathing rate as 18 breaths per minute at rest. After performing vigorous exercise, their breathing rate increases to 36 breaths per minute. Explain the physiological reason for this change.

Answer: During exercise, the body requires more oxygen and needs to expel more carbon dioxide, so the breathing rate increases to meet these demands.

Question 1: Describe the process of inspiration and explain the roles of the diaphragm and intercostal muscles in this process. (6 marks)

Answer: Inspiration involves the contraction of the diaphragm, which moves downward, and the intercostal muscles, which lift the rib cage. This increases the volume of the thoracic cavity, reducing pressure inside the lungs and drawing air in. The diaphragm's movement and intercostal muscles work together to facilitate the intake of air during breathing.

Question 1: Explain how understanding the breathing mechanism is important in the design of ventilators used in hospitals.

Answer: Understanding how the lungs and respiratory muscles work helps in designing ventilators that can simulate natural breathing, ensuring proper oxygen delivery and carbon dioxide removal in patients.

Question 2: Discuss how regular physical activity can influence lung capacity and breathing efficiency.

Answer: Regular physical activity can increase lung capacity, improve the strength of respiratory muscles, and enhance overall breathing efficiency by enabling the lungs to expand more effectively.