Tag: the mechanism of breathing

Questions Related to the mechanism of breathing

Choose the correct answer from the alternatives given.
In which of the following structures vocal cords are located?

  1. Oesophagus

  2. Larynx

  3. Pharynx

  4. Bronchi


Correct Option: B
Explanation:

The vocal cords are folds of membranous tissue that are located within the larynx at the top of the trachea. Their edges vibrate in an airstream to produce voice. So, the correct option is 'Larynx'.

Choose the correct answer from the alternatives given.
In the nostril the air is

  1. warned

  2. filtered

  3. moistened

  4. all of these


Correct Option: D
Explanation:

The nostrils carry out the necessary conditioning of inhaled air by warming and moistening it and the nasal hair present in the nostrils prevents large particles from entering the lungs by filtering the air. So, the correct option is 'all of these'.

Choose the correct answer from the alternatives given.
The Adams apple is formed predominantly, by which of the following structures?

  1. Larynx

  2. Pharynx

  3. Oesophagus

  4. Bronchi


Correct Option: A
Explanation:

The Adam's apple is a laryngeal protrusion that is formed by the angle of the thyroid cartilage surrounding the larynx and is seen especially in males. So, the correct option is 'larynx'.

Insect tracheal system opens to the outside through 

  1. Spiral value

  2. Pecten

  3. Spiracle

  4. Taenidia


Correct Option: A

Which of the following option is correct regarding the characteristics of the diaphragm?


(A) Found in mammals.
(B) Separate the thoracic and Abdominal cavity.
(C) Formed by inter-costal muscles.
(D) Due to its contraction volume of thoracic cavity increases on Anterior-Posterior axis.

  1. A, C and D are correct

  2. A, B and D are correct

  3. B, C and D are incorrect

  4. A, B and C are incorrect


Correct Option: A
Explanation:

  • The diaphragm is the type of skeletal muscle found in mammals which plays a major role in respiration. It is a dome-shaped structure and moves in and out at the time of respiration. Its muscles separate the thoracic cavity having heart and lungs from the abdominal cavity. 
  • During inhalation, the diaphragm contracts and chest cavity increases to get more oxygen while in exhalation diaphragm relaxes and the chest cavity decreases and releases carbon dioxide.

So, the correct option is 'Found in mammals, Separate the thoracic and Abdominal cavity, and Due to its contraction volume of the thoracic cavity increases on Anterior-Posterior axis'.

During respiration exchange of gases takes place in _________.

  1. Trachea

  2. Alveoli

  3. Throat

  4. Larynx


Correct Option: A

Which of the following changes occur in diaphargm relax and intercostal muscles when expiration of air takes place?

  1. External intercostal muscles relax and diaphargm contracts

  2. External intercostal muscles contract and diaphargm relax.

  3. External intercostal muscles contract and diaphargm relaxes

  4. External intercostal muscles and diaphargm contract


Correct Option: A

One of the following depend more on ribs and their muscles for breathing than diaphragm.

  1. Female (human)

  2. Monkey

  3. Kangaroo

  4. All of the above


Correct Option: D
Explanation:

The ribs and the various muscles of respiration aid in both inspiration and expiration, which require changes in the pressure within the thoracic cavity. The important respiratory muscles are the diaphragm, the external intercostal and the internal intercostal muscles. The ribs and the respiratory muscles work to achieve this by changing the dimensions of the thoracic cavity.
When a person inhales, the rib cage move out and up in order to accommodate the incoming air. On the other hand, when a person exhales, the rib cage move in, in order to expel the carbon dioxide. Both the external intercostal muscles and the internal intercostal muscles elevate the ribs, thus increasing the width of the thoracic cavity, while the diaphragm contracts to increase the vertical dimensions of the thoracic cavity, and also aids in the elevation of the lower ribs. The muscles that connect the ribs together ensure that the diaphragm can expand and contract appropriately as air is breathed in and expelled. Thus, in mammals, breathing depends more on ribs and their muscles for breathing than diaphragm.

The respiratory organs in cockroach are

  1. Lungs

  2. Gills

  3. Lenticels

  4. Spiracles


Correct Option: D
Explanation:

  • Spiracles are openings on the surface of some animals, which usually lead to respiratory systems. 
  • The spiracle is a small hole behind each eye that opens to the mouth. Insects and some more derived spiders have spiracles on their exoskeletons to allow air to enter the trachea.
  •  In the respiratory system of insects, the tracheal tubes primarily deliver oxygen directly into the animals' tissues. 
  • The spiracles can be opened and closed in an efficient manner to reduce water loss. Hence, The respiratory organs in cockroach are spiracles.
So, the correct answer is 'spiracles'.

______ is the muscle responsible in respiration.

  1. Diaphragm

  2. Muscle tissue

  3. Heart

  4. Lungs


Correct Option: A
Explanation:

Diaphragm is a muscular and tendinous sheath that closes the opening between thorax and abdomen and is pierced by structures that pass between these two regions of the body. The diaphragm is the primary muscle of respiration. Diaphragm is the primary respiratory muscle of the body. It, on contraction, increases the vertical diameter of the chest cavity by pulling its central tendon downwards. In this way, the lungs get extra space to expand and air rushes into them.