Question

Which respiratory associated muscles would be contracted if you blow up a balloon?
(A) Diaphragm contracts and internal intercostal muscles would relax
(B) External intercostal muscle contract and the phrenic muscles would contract
(C) Internal intercostal and the abdominal muscle would contract.
(D) Internal intercostal muscles are external intercostal muscles.

Answer 1

Hint: Inhalation or breathing is the process in which the air is inhaled into the lungs. It is similar to the blowing up of the balloon. And the breathe out is defined as the carbon dioxide used from the metabolism moves out to the external environment through the nose. Alveoli is the point where the exchange of the gases takes place.

Complete Answer:
- Alveoli is the balloon-like structures that are present within the lungs. They have the connection with the lungs and the blood capillaries. This helps in transferring the gases between the blood and the lungs.
- At the time of the inhalation, the diaphragm moves down and inward. All the intercostal muscles located in the chest region and the abdominal muscles contract in order to offer the lungs with more volume to hold upon the incoming air.
- So that there will be high pressure in the interior of the lungs. At the time of the exhalation, the carbon dioxide moves forcefully out to the atmosphere, at that time, the diaphragm moves upward and outward. Hence the internal intercostal muscle and abdominal muscles expand.

Thus the option (C) is correct.

Note: The muscles that are mainly involved in the process of respiration as the scalene, the sternocleidomastoid, the trapezius, and the pectoralis major, internal and the external intercostal muscles. They help in stretching themselves for the holding up of the air and to release it to the external environment.