Question

Short/long answer type questions.
Write short notes on:
(a)Vital capacity, (b) Tidal volume, (c) Artificial respiration, (d) Inspiratory reserve volume, (e) Chloride shift.

Answer 1

Hint: Lung volumes and lung capacities refer to the volume of air in the lungs at different phases of the respiratory cycle. Four standard lung volumes are; tidal volume, inspiratory reserve volume, expiratory reserve volume, and residual volumes. Artificial respiration is a first-aid employed to ensure some degree of gas exchange.

Complete answer:
(a) Vital capacity: Vital lung capacity is the maximum amount of air a person can expel from the lungs after a maximum inhalation. It is equal to the sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume. It is approximately equal to Forced Vital Capacity. A normal adult has a vital capacity between 3 and 5 liters.
(b) Tidal Volume: Volume of air inspired or expired during normal respiration. It normally is 500 ml. It is the volume of lungs representing the normal volume of air displaced between normal inhalation and exhalation when extra effort is not applied. In a healthy, young human adult, tidal volume is approximately 500 ml per inspiration. Tidal volume is measured in milliliters and ventilation volumes are estimated based on a patient’s ideal body mass.
(c) Artificial respiration: It is a life-saving step or a first-aid, employed to ensure some degree of gas exchange when normal respiration fails and heart-beat continues. It is any method that causes air to flow in a person's lungs when natural breathing is inadequate or ceases, as in respiratory paralysis, choking, drowning, etc.
(d) Inspiratory reserve volume: Additional volume of air a person can inspire by forceful inspiration. inspiratory reserve volume is the additional amount of air that can be inhaled after a normal inhalation. It is 2500-3000 ml.
(d) Chloride shift: It is a process that describes the exchange of chloride and bicarbonate ions across the membrane of red blood cells. It is the exchange of chloride and carbonate between the plasma and the erythrocytes that take place when the blood gives up oxygen and receives carbon dioxide. It serves to maintain ionic equilibrium between the cell and surrounding fluid.

Additional Information:
- A human’s vital capacity depends on age, sex, height, mass, etc.
- Tidal volume plays a significant role during mechanical ventilation to ensure adequate ventilation without causing trauma to the lungs.
- The residual volume is the amount of air that is left after the expiratory reserve volume is exhaled.

Note:
- The rate at which artificial respiration is administered must coincide with the rate of normal ventilation. Ventilation is the passing of air into and out of the lungs along the respiratory tract.
- Different animals exhibit different lung capacities based on their activities. For example, cheetahs have evolved a much higher lung capacity than humans in order to provide oxygen to all the muscles in the body, allowing them to run very fast.
- Elephants also have a high lung capacity due to their large body and their need to take up oxygen in accordance with their body size.