Question

Which is the correct sequence of air passage during inhalation?
A. Nostrils $\to$ larynx $\to$ pharynx $\to$ trachea $\to$ lungs
B. Nasal passage $\to$ trachea $\to$ pharynx $\to$ larynx $\to$alveoli
C. Larynx $\to$ nostrils $\to$ pharynx $\to$ lungs
D. Nostrils $\to$ pharynx $\to$larynx $\to$ trachea $\to$ alveoli

Answer 1

Process of inhalation belongs to the respiration process which occurs in the respiration system of the body. It is an active process that requires contraction of skeletal muscles. Air first enters the nasal chamber through nostrils.

Complete answer:
The main respiratory organ in the human body is the lungs. They bring oxygen into the body and remove carbon dioxide outside the body. This process of exchange of gases is known as respiration. There are two ways by which air can enter into our body one's nose (nasal cavity) and another is mouth. These two openings of air passage meet at the pharynx at the back of nose and mouth. Pharynx is a part of both digestive systems and respiratory tract because it can carry food as well as air. After passing through the pharynx air enters the larynx. Larynx is present just below the pharynx. Opening of the larynx is surrounded by a small flap of tissues that automatically closes during swallowing. This prevents food from entering the airways. Air moves from the larynx to the trachea which is a tubular structure consisting of dense connective tissues. Trachea divides into two bronchi Right and left that keeps dividing and give rise to alveolar duct. Air goes to alveoli through bronchioles for exchange of blood.

Thus the correct answer is D.

Note:
The respiratory system starts at the nose and mouth and continues through airways and lungs. The airways have three main functions: first is to act as channels for exchange of gases , second is to protect lungs from any foreign matter and third is to control heat and humidity of gases. Diffusion of gases takes place in alveoli.