Question

Name the body structure concerned with the given functional activity: helps to increase the volume of the chest cavity lengthwise.

Answer 1

A dome-shaped or C-shaped structure muscle that helps increase the volume of the thoracic cavity length-wise. It is present at the inferior surface on the roof of the abdominal cavity.

Complete answer:
The diaphragm is a muscular, membranous structure that separates abdominal and thoracic cavities in mammals. It acts as a principal muscle in respiration. The muscle for the diaphragm arises from the lower part of the sternum. The contraction of the diaphragm increases the volume of the thoracic cavity, which reduces the internal pressure and leads to the inspiration of air into the lungs. Diaphragm relaxation, the natural elasticity of the lung, and thoracic cage help in the process of expiration. It is located at the inferior part of the ribcage and is usually unpaired. It is made up of a sheet of muscle and tendon.

Note: The diaphragm extends across the bottom of the thoracic cavity. It helps in separating the heart and lungs from the abdominal cavity. It is an internal skeletal muscle. The contraction of the diaphragm increases the volume of the thoracic cavity that results in creating a negative pressure to draw air into the lungs. It helps in creating a vacuum effect to pull the air into the body. During exhalation, the diaphragm relaxes and releases the air from the body. It is a membranous structure. It is a principal muscle for the process of respiration.