Final answer:
The diaphragm is the muscle that aids in drawing air into the lungs of mammals when it contracts. It alters the pressure within the chest cavity to facilitate inhalation and exhalation, aided by intercostal muscles and the structure of the thoracic cavity.
Step-by-step explanation:
Structure Aiding in Inhalation
The structure that aids in drawing air into the lungs of mammals as it contract is the diaphragm. This dome-shaped muscle is located below the lungs and extends across the bottom of the chest cavity.
When the diaphragm contracts, it flattens and increases the volume of the chest cavity, which in turn decreases the pressure inside, allowing air to be drawn into the lungs. During exhalation, the diaphragm relaxes, and the volume of the chest cavity decreases, pushing air out of the lungs.
Mechanics of Breathing
The thoracic cavity and its associated muscles, including the intercostal muscles, play a crucial role in the mechanics of breathing.
These muscles aid in changing the volume and pressure within the pleural cavities, which helps air flow in and out of the lungs. In addition, alveoli within the lungs provide a large surface area for efficient gas exchange between the air and the blood.