Biology

Respiration and Gas Exchange

989 Questions

Access a targeted set of questions on respiration and gas exchange for competitive exams. Topics include lung volumes, the mechanism of breathing, and respiratory anatomy. Understanding these physiological processes is essential for scoring well.

Lung volumes and capacitiesBreathing mechanismsRespiratory anatomyGas exchange processes

Respiration and Gas Exchange Questions

Multiple choice

Which of the following is a primary inspiratory muscle?

  1. Sternocleidomastoid muscle

  2. Scaleni

  3. Abdominal muscle

  4. External intercostal

  5. Anterior serratus
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The muscles extend from the tubercles of the ribs behind, to the cartilages of the ribs in front, where they end in thin membranes. These muscles work in unison during inhalation. The internal intercostal muscles relax while the external muscles contract, causing the expansion of the chest cavity and an influx of air into the lungs.

Multiple choice

Which of the following give rise to respiratory bronchioles?

  1. Alveoli

  2. Lobar bronchi

  3. Terminal bronchi

  4. Terminal bronchioles
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

After a few divisions, terminal bronchioles give rise to respiratory bronchioles. After a few division, terminal bronchioles gives rise to respiratory bronchioles.

Multiple choice

Which of the following is incorrect regarding the different steps of respiration?

  1. Breathing or pulmonary ventilation facilitates intake of alveolar air and expulsion of atmospheric air.

  2. Diffusion of gases takes place across alveolar membrane.

  3. Oxygen is transported to the tissue by blood.

  4. Diffusion of O2 and CO2 takes place between blood and tissues.

  5. Catabolism leads to utilisation of O2 by the cells and the release of CO2.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Breathing or pulmonary ventilation facilitates intake of atmospheric air and expulsion of alveolar air.

Multiple choice

What prevents dust particles from getting into the respiratory system?

  1. Fine hair and mucus in the nose

  2. The air pipe in the nose is very thin

  3. There are bends in the air way in the nose

  4. The skin inside the nose acts as dust conditioner

  5. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Correct. Fine hair and mucus are present inside the nose to prevent dust particles from getting into the respiratory system.

Multiple choice

The mechanism of breathing through deepening the inhale in an organism is regulated by ___________.

  1. the Hering-Breuer reflex

  2. the spinal cord reflex

  3. the nasopulmonary and nasothoracic reflexes

  4. central chemoreceptors

  5. peripheral chemoreceptors
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The nasopulmonary and nasothoracic reflexes regulate the mechanism of breathing through deepening the inhale. Triggered by the flow of air, the pressure of the air in the nose, and the quality of the air, impulses from the nasal mucosa are transmitted by the trigeminal nerve to the breathing centres in the brainstem and the generated response is transmitted to the bronchi, the intercostal muscles and the diaphragm.

Multiple choice

In mammals, the process of ventilation is normally controlled by the autonomic nervous system. Which among the following statements does not characterizes ventilation in humans?

  1. Afferent neurons from the carotid bodies and aortic bodies are via the glossopharyngeal nerve.

  2. During moderate exercise, ventilation increases in proportion to metabolic production of carbon dioxide.

  3. Ventilatory rate is usually controlled and determined by blood levels of oxygen as determined by metabolic rate.

  4. The tone of respiratory muscle is modulated by muscle spindles via a reflex arc.

  5. Pregnancy tends to increase ventilation.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ventilatory rate (minute volume) is strictly controlled and determined primarily by blood levels of carbon dioxide as determined by metabolic rate. Blood levels of oxygen become important in hypoxia. These levels are sensed by chemoreceptors in the medulla oblongata for pH, and the carotid and aortic bodies for oxygen and carbon dioxide.

Multiple choice

Which among the following structures is responsible for warming or cooling of inhaled air within 1 degree of body temperature?

  1. The nasal cavity

  2. The nasopharynx

  3. The larynx

  4. The oropharynx

  5. The laryngopharynx
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The nasal cavity conditions the air to be received by the other areas of the respiratory tract. Owing to the large surface area provided by the nasal conchae, the air passing through the nasal cavity is warmed or cooled to within 1 degree of body temperature.

Multiple choice

Which among the following statements regarding the human lungs is incorrect?

  1. The right lung has a higher volume, total capacity and weight than that of the left lung.

  2. The lower, oblique fissure separates the inferior from the middle and superior lobes.

  3. The upper horizontal fissure separates the superior from the middle lobe.

  4. The inferior lobe is the smallest lobe of the right lung.

  5. The development of the human lungs arises from the laryngotracheal groove.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The middle lobe is the smallest lobe of the right lung. It is wedge-shaped and includes the part of the anterior border and the anterior part of the base of the lung.

Multiple choice

The lung capacity is defined as the maximum air which can be held in the two lungs at any given time. Which among the following has minimum value?

  1. Vital capacity

  2. Expiratory reserve volume

  3. Inspiratory reserve volume

  4. Residual air

  5. Alveolar air
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Some amount of air remains in the various parts of the respiratory tract. The air in the trachea and bronchi (where no diffusion occurs) is called dead space air (350ml). The air remaining in the alveoli or air sacs is alveolar air (150ml).

Multiple choice

Which among the following can be excluded from the events taking place during the process of inspiration?

  1. Inspiration is initiated by contraction of the diaphragm.

  2. During normal quiet breathing, the phrenic nerves stimulate the diaphragm to contract.

  3. As long as pressure within the alveoli is higher than atmospheric pressure, air will continue to move inwardly.

  4. As the diaphragm contracts, the volume of the thoracic cavity increases.

  5. The lungs are held to the thoracic wall by negative pressure in the pleural cavity.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

As long as pressure within the alveoli is lower than atmospheric pressure, air will continue to move inwardly. But as soon as the pressure is stabilized, air movement stops.