Question
The Total Lung Capacity (TLC) is the total volume of air accommodated in the lungs at the end of a forced inspiration. This includes [NEET (Oct.) 2020]
(a) RV, IC (Inspiratory Capacity), EC (Expiratory Capacity) and ERV
(b) RV, ERV, IC and EC
(c) RV, ERV, VC (Vital Capacity) and FRC (Functional Residual Capacity)
(d) RV (Residual Volume), ERV (Expiratory Reserve Volume), TV (Tidal Volume) and IRV (Inspiratory Reserve Volume)
Answer/Explanation
Ans. (d)
The Total Lung Capacity(TLC) is the total volume of air accommodated in the lungs at the end of a forced inspiration. This includes Residual Volume (RV) Expiratory Reserve Volume (ERV], Tidal Volume (TV) and Inspiratory Reserve Volume (IRV). TLC is also equals to vital capacity of residual volume. Thus, option $(d)$ is correct.
Question
The maximum volume of air a person can breathe in after a forced expiration is known as [NEET (Odisha) 2019]
(a) expiratory capacity
(b) vital capacity
(c) inspiratory capacity
(d) total lung capacity
Answer/Explanation
Ans. (b)
Vital Capacity (VC) is the maximum volume of air a person can breathe in after a forced expiration. This includes ERV, TV and IRV or the maximum volume of air a person can breathe out after a forced inspiration.
Question
Tidal Volume and Expiratory Reserve Volume of an athlete is $500 \mathrm{~mL}$ and $1000 \mathrm{~mL}$, respectively. What will be his Expiratory Capacity if the Residual Volume is $1200 \mathrm{~mL}$ ? [NEET (National) 2019]
(a) $1700 \mathrm{~mL}$
(b) $2200 \mathrm{~mL}$
(c) $2700 \mathrm{~mL}$
(d) $1500 \mathrm{~mL}$
Answer/Explanation
Ans. (d)
The Expiratory Capacity of athlete will be $1500 \mathrm{~mL}$. It can be calculated as Given, Tidal Volume [TV] $=500 \mathrm{~mL}$
Expiratory Reserve Volume[ERV] $=1000 \mathrm{~mL}$
Expiratory Capacity $=T V+E R V$
$
=500+1000=1500 \mathrm{~mL}
$
Question
Match the items given in Column I with those in Column II and select the correct option given below [NEET 2018]
1 2 3 4
(a) i iv ii iii
(b) iii i iv ii
(c) iii ii i iv
(d) iv iii ii i
Answer/Explanation
Ans. (b)
Tidal Volume (TV) is the volume of air inspired or expired during normal breath. It is about 500-550 mL.
Inspiratory Reserve Volume (IRV) is the extra amount of air that can be inspired directly after a normal inspiration. It is about 2500-3000 mL.
Expiratory Reserve Volume (ERV) is the extra amount of air that can be expired forcibly after a normal expiration. It is about $1000-1100 \mathrm{~mL}$. Residual Volume (RV) is the volume of air which remains still in the lung after the most forceful expiration. It is about $1100-1200 \mathrm{~mL}$.
Therefore, option (b) is correct.
Question
Lungs are made up of air-filled sacs, the alveoli. They do not collapse even after forceful expiration, because of [NEET 2017]
(a) Residual Volume (RV)
(b) Inspiratory Reserve Volume(IRV)
(c) Tidal Volume (TV)
(d) Expiratory Reserve Volume (ERV)
Answer/Explanation
Ans. (a)
In lungs, even after the most forceful expiration, some of the volume of air remains. This volume is termed Residual Volume (RV). Due to this, lungs do not collapse even after the most forceful expiration. RV is about 1100 $\mathrm{mL}-1200 \mathrm{~mL}$.
Question
Lungs do not collapse between breaths and some air always remains in the lungs which can never be expelled because [NEET 2016, Phase II]
(a) there is a negative pressure in the lungs
(b) there is a negative intrapleural pressure pulling at the lung walls
(c) there is a positive intrapleural pressure
(d) pressure in the lungs in higher than the atmospheric pressure
Answer/Explanation
Ans. (b)
Lungs do not collapse between breaths and some air always remains in the lungs which can be never expelled because there is a negative intrapleural pressure pulling at the lung walls. Alveoli are basic functional unit of lungs. The outer alveolar wall surface has cells which secrete DPPC also called as lipid surfactant. The surfactant expands the alveoli due to which the negative pressure inside the alveoli increases. This prevents the alveoli from collapsing. Since, in this question both options (a) and (b) are correct and option(b) provides more appropriate explanation, therefore, it must be chosen.
Question
Listed below are four respiratory capacities (1-4) and four jumbled respiratory volumes of a normal human adult
Respiratory
Respiratory
Capacities Volumes
1. Residual volume $2500 \mathrm{~mL}$
2. Vital capacity $3500 \mathrm{~mL}$
3. Inspiratory reserve volume 1200 $\mathrm{mL}$
4. Inspiratory capacity $4500 \mathrm{~mL}$ Which one of the following is the correct matching of two capacities and volumes? [CBSE AIPMT 2010] (a)(2) $2500 \mathrm{~mL}$, (3) $4500 \mathrm{~mL}$ (b)(3) $1200 \mathrm{~mL}$, (4) $2500 \mathrm{~mL}$ (c) (4) $3500 \mathrm{~mL} ,$ (1) $1200 \mathrm{~mL}$ (d)(1) $4500 \mathrm{~mL}$, (2) $3500 \mathrm{~mL}$
Answer/Explanation
Ans. (c) Inspiratory Capacity (IC) is the maximum amount of air that can be inspired after a normal expiration, $\mathrm{IC}=\mathrm{TV}+\mathrm{RRV}$. It is $3500 \mathrm{~mL}$ in adult male and $2400 \mathrm{~mL}$ in adult female.
Residual Volume (RV) is the amount of air remaining in the lungs after a forced exhalation. Its average value is $1200 \mathrm{~mL}$ and $1100 \mathrm{~mL}$ in adult male and female respectively.
Question
What is the vital capacity of our lungs? [CBSE AIPMT 2008]
(a) Inspiratory reserve volume plus tidal volume
(b) Total lung capacity minus expiratory reserve volume
(c) Inspiratory reserve volume plus expiratory reserve volume
(d) Total lung capacity minus residual volume
Answer/Explanation
Ans. (d)
Vital capacity is the sum of inspiratory reserve volume, tidal volume and expiratory reserve volume. It is about $4800 \mathrm{~mL}$. Total lung capacity is the sum of vital capacity and residual volume, i.e., vital capacity of our lungs is total lung capacity minus residual volume. Tidal volume is the amount of air which normally passes into and out of the lungs during each cycle of quite breathing. It is about $800 \mathrm{~mL}$ in adult person. Inspiratory reserve volume is the extra volume of air that can be inhaled into lungs during deepest possible inspiration.
Question
The quantity $1500 \mathrm{~mL}$ in the respiratory volumes of a normal human adult refers to [CBSE AIPMT 1996]
(a) maximum air that can be breathed in and breathed out
(b) residual volume
(c) expiratory reserve volume
(d) total lung capacity
Answer/Explanation
Ans. (b)
Residual air is the volume of air that remains in the lungs after the most forceful expiration. It equals to $1500 \mathrm{~mL}$. Residual air mostly occurs in alveoli. Maximum air that can be breathed in and breathed out is vital capacity $(3500-4500 \mathrm{~mL})$ while the air that can be expired over and above the tidal air by most forceful expiration is the expiratory reserve volume $(1200 \mathrm{~mL})$.