Question

If a person exhales out forcefully by applying all his efforts, what will be the pulmonary volume inhaled by him immediately under the normal condition without applying any extra effort?
A. TV+IRV
B. Only TV
C. TV+ERV
D. TV+IRV+ERV

Answer 1

Pulmonary ventilation is the process of breathing that is the movement of air into and out of the lungs. Three major factors responsible for pulmonary ventilation include the atmospheric pressure (Patm), the alveolar pressure (Palv), and the intrapleural pressure (Piv).

Complete answer:
The process of pulmonary ventilation mainly occurs in two steps, including inspiration and expiration. Inspiration is the process by which the air enters the lungs, whereas expiration is the process by which the air leaves the lungs. A respiratory cycle is one such sequence of inspiration followed by expiration. Various muscles such as diaphragm and intercostal muscles are involved in this usual breathing process.
Respiratory volume refers to the volume of air associated with the lungs at a given point in the respiratory cycle. Tidal volume (TV) is defined as the amount of air that enters the lungs during normal breathing. The expiratory reserve volume (ERV) is the amount of air which can be forcefully exhaled after a normal tidal expiration. The inspiratory reserve volume (IRV) is that amount of air which can be forcefully inhaled after a normal inspiration. This extra amount of air that can be brought into the lungs by a forceful inspiration is called the residual volume (RV). In case of a forceful expiration, the amount of air inhaled back by him will include the tidal volume, the expiratory reserve volume and also the inspiratory reserve volume.
Therefore, under the normal condition, the pulmonary volume inhaled by the person immediately after his forceful exhalation is considered as the sum of TV, IRV and ERV.
So, the correct answer is “Option D”.

Note:
Lung is the main respiratory organ that allows an exchange of gases such as oxygen and carbon dioxide. This occurs by inhalation or inspiration of oxygen, which is then followed by exhalation or expiration of carbon dioxide. The total lung capacity can be defined as the total of four volumes, including TV, IRV, ERV, and RV.