Question

During inspiration muscles of diaphragm
a. Contracts
b. Expands
c. No effect
d. Coiled like string

Answer 1

Hint: Respiration is one of the most important biological systems of humans. In this process, the human takes up oxygen and expels carbon dioxide. Different types of organs and muscles are involved in the process of respiration. The diaphragm is such a muscle that is involved in breathing.

Complete answer:
Respiration is a biological process of the human being. In the process of respiration, respiratory gases such as oxygen is taken in and carbon dioxide is given out. Generally, there are two types of respiration processes noticed in humans. One is external respiration which involves the inhalation of oxygen and exhalation of carbon dioxide. And the other is internal respiration which functions between blood and body cells.

In humans, respiration takes place through the lungs which is the prime organ of respiration and muscles which are known as respiration muscles. The lungs are the largest organ of the human respiratory system. The air entered through the trachea into the lungs and exchange of oxygen and carbon dioxide takes place. Carbon dioxide is then released out of the lungs and then the body through the mouth. There are two processes involved in respiration, inspiration and expiration. The process of taking in the air is known as inspiration and the process of breathing out the air is called expiration.

There are several muscles involved in the process of inspiration and expiration. The diaphragm is such a muscle that is involved in the process of breathing. It is a thin, dome-shaped muscle. The diaphragm is used to separate the abdominal cavity from the thoracic cavity.

During inhalation or inspiration, the diaphragm contracts. THe diaphragm is pulled downwards. Due to this contraction, the centre of the diaphragm steps downward and its edges step upward at the same time. Due to the compression of the abdominal cavity, the ribs are upward and outward, and the thoracic cavity gets stretched. The air inhales into the lungs due to this expansion.

In expiration, the diaphragm relaxes into its dome shaped shape and volume of the thoracic cavity is decreased and the pressure increases. This causes contraction of the lungs.

Hence, the correct answer is option (A).

Note: Respiration is the most important biological process of all living elements. During the respiration oxygenated air inhales into the lungs and carbon dioxide releases from the body. The process of inhalation of air is called inspiration and the process of expelling carbon dioxide is called expiration. There are several respiration muscles performing the process of breathing. During the inspiration, the diaphragm contracts which lead to the thoracic cavity expansion and the air gets in.