Question

Which of the following structures are responsible for breathing process?

• A. The trachea and alveoli
• B. Larynx and bronchi
• C. Ribs and intercostal muscles
• D. Intercostal muscles and diaphragm

Answer 1

Answer: (D)

Intercostal muscles and diaphragm

Breathing or pulmonary ventilation is a process where the nasal and oral cavities inhaled the air and enter into the lungs through the pharynx, larynx and trachea. Air is also exhaled through the same pathway. While larynx, pharynx and trachea are involved the changes to the volume and air pressure in the lungs trigger breathing. During the process of inhalation, the diaphragm and external intercostal muscles contract thereby elevating the rib cage. With the increase in the volume of the lungs, air pressure drops letting the air rush in. Similarly, during exhalation, the muscles relax letting the lungs become smaller, which raises the air pressure and helps to expel the air.

Hence the correct option is D.