Tag: respiratory system of human

Questions Related to respiratory system of human

Which of the following is the most appropriate in normal circumstances?

  1. During inspiration the intrapulmonary pressure is less than the atmospheric pressure

  2. During expiration the intrapulmonary pressure is less than the atmospheric pressure

  3. During inspiration the intrapulmonary pressure is more than the atmospheric pressure

  4. During expiration the intrapulmonary pressure is equal to atmospheric pressure


Correct Option: A

Diaphragm is straightened during.

  1. Expiration

  2. Inspiration

  3. Interval between expiration and inspiration

  4. Interval between inspiration and expiration


Correct Option: A

A person breathes in some volume of air by forced inspiration after having a forced expiration. This quantity of air taken in is _______________.

  1. Total lung capacity

  2. Tidal volume

  3. Vital capacity

  4. Inspiratory capacity


Correct Option: A

During inspiration, the pressure of air is maximum in ___________.

  1. Trachea

  2. Bronchus

  3. Alveoli

  4. Environment


Correct Option: A

In negative pressure breathing, inhalation results from:

  1. forcing air from the throat down into the lungs

  2. contracting the diaphragm

  3. relaxing the muscles of the rib cage

  4. contracting the abdominal muscles


Correct Option: B
Explanation:

During the process of inhalation, the lung volume expands as a result of contraction of the diaphragm & intercostal muscles, thoracic cavity expands, due to this increase in volume, the pressure is decreased.

So, the correct option is 'contracting the diaphragm'.

During expiration the diaphragm becomes

  1. dome-shaped

  2. oblique

  3. concave

  4. flattened.


Correct Option: A
Explanation:

When the internal intercostal muscles contract and diaphragm relax, the ribs move .downward and inward and diaphragm becomes convex {dome shaped), thus decreasing the volume of thoracic cavity and increasing the pressure inside as compared to the atmospheric pressure outside. This will cause the air to move out (expiration).

After forceful inspiration, the amount of air that can be breathed out by maximum forced expiration is equal to

  1. Inspiratory Reserve Volume (IRV) + Expiratory Reserve Volume (ERV) + Tidal Volume (TV) + Residual Volume (RV)

  2. IRV + RV + ERV

  3. IRV + TV + ERV

  4. TV + RV + ERV


Correct Option: C
Explanation:

Vital capacity is the maximum volume of air a person can breathe in after a forced expiration or the maximum volume of air a person can breathe out after a forced inspiration.This equals the inspiratory reserve volume (IRV) + expiratory reserve volume (ERV) + tidal volume (TV). Its value is 3400 mL - 4800 mL..

Read the following four statements (i) - (iv) with certain mistakes in two of them.
(i) A water breather expends much more energy in ventilating its respiratory surface than an air-breathing one.
(ii)   Lungs become empty after forceful expiration.
(iii) Exchange of gases in the lungs is interrupted during expiration.
(iv) Respiratory movements are controlled by $CO _{2}$ concentration of arterial blood.
Which of the above two statements have mistakes?

  1. (i) and (iv)

  2. (ii) and (iii)

  3. (i)and(ii)

  4. (iii) and (iv)


Correct Option: B
Explanation:

 Corrected statements:

(ii) Lungs do not become empty after a forceful expiration.

(iii) The exchange of gases in the lungs is not interrupted during expiration.

So, the correct answer is '(ii) and (iii)'.

Mark the correct pair of muscles involved in the normal breathing in humans.

  1. External and internal intercostal muscles

  2. Diaphragm and abdominal muscles

  3. Diaphragm and external intercostal muscles

  4. Diaphragm and intercostal muscles


Correct Option: D
Explanation:
Breathing involves two stages : inspiration during which atmospheric air is drawn in and expiration by which the alveolar air is released out. Inspiration can occur if the. pressure within the lungs (intra-pulmonary pressure) is less than the atmospheric pressure, i.e., there is a negative pressure in the lungs with respect to atmospheric pressure. Similarly, expiratibn takes place when the intra-pulmonary pressure is higher than the atmospheric pressure. The diaphragm and a specialised set of muscles-external and internal intercostals between the ribs, help in generation of such gradients.
So, the correct answer is 'Diaphragm and intercostal muscles'.

Which of the following statement is correct?

  1. During inspiration external intercoastal muscles and diaphragm contract

  2. Coryza is caused by human corona virus

  3. Cyanosis means collapse of alveoli

  4. Eupnea is slow breathing


Correct Option: A
Explanation:

During inspiration external intercoastal muscles and diaphragm contract because it allows air to be moved into the lungs and requires the contraction of various musceles; the diaphragm and external intercoastal muscles contract.