Question 1: Define the term 'respiration' as it relates to the respiratory system.

Answer: Respiration is the biological process in which organisms convert oxygen and nutrients into energy, releasing carbon dioxide and water as byproducts.

Question 2: Explain how inhalation and exhalation differ in terms of the diaphragm's movement and the pressure changes in the thoracic cavity.

Answer: During inhalation, the diaphragm contracts and moves downward, increasing the thoracic cavity volume and decreasing pressure, allowing air to enter. During exhalation, the diaphragm relaxes and moves upward, decreasing thoracic volume and increasing pressure, pushing air out.

Question 3: What is the role of alveoli in the respiratory system?

Answer: Alveoli are tiny air sacs in the lungs where gas exchange occurs; oxygen diffuses into the blood, and carbon dioxide diffuses out to be exhaled.

Question 1: Calculate the amount of oxygen consumed during a 1-hour breathing session if an average person inhales 500 ml of air per breath, takes 12 breaths per minute, and the air contains 21% oxygen. Use the formula: Oxygen consumed = (Volume of air per minute) × (Fraction of oxygen) × (Time in minutes).

Answer: Oxygen consumed = 500 ml × 12 breaths/min × 1 min × 60 min × 0.21 = 75,600 ml

Question 1: Describe a safe method to measure respiratory rate in a patient, including necessary precautions.

Answer: To measure respiratory rate safely, observe the patient's chest movements for 60 seconds while ensuring the patient is comfortable and relaxed. Wash hands before and after, and avoid disturbing the patient during measurement.

Question 2: Identify two variables you could change in an experiment to test the effect of exercise on breathing rate.

Answer: Variables could include the intensity of exercise (e.g., walking vs. running) and the duration of exercise.

Question 1: A group of students recorded their breathing rates at rest and after running for 5 minutes. Resting rates ranged from 12-16 breaths per minute, while post-exercise rates ranged from 24-36 breaths per minute. What does this data suggest about the effect of exercise on breathing rate?

Answer: The data suggests that exercise increases the breathing rate, likely to supply more oxygen to meet increased energy demands during physical activity.

Question 1: Describe the sequence of events in the breathing mechanism from inhalation to exhalation, including the role of the diaphragm, intercostal muscles, and lung pressure changes. (6 marks)

Answer: During inhalation, the diaphragm contracts and moves downward, and the intercostal muscles raise the ribs, increasing thoracic volume and decreasing lung pressure, causing air to flow in. During exhalation, the diaphragm relaxes and moves upward, ribs lower, thoracic volume decreases, lung pressure increases, and air is pushed out.

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

Answer: Understanding the breathing mechanism helps engineers design ventilators that accurately mimic natural breathing patterns, ensuring proper oxygen delivery and safe removal of carbon dioxide in patients who cannot breathe independently.

Question 2: Describe how pollutants like sulfur dioxide and particulate matter can affect the breathing mechanism and overall respiratory health.

Answer: Pollutants like sulfur dioxide and particulate matter can irritate the respiratory tract, reduce lung function, cause inflammation, and increase the risk of respiratory diseases such as bronchitis and asthma.