Answer:
Air enters the body through the respiratory system, which is responsible for the exchange of gases (oxygen and carbon dioxide) between the body and the environment. The correct sequence for air to follow as it enters the body is:
Nose or mouth: Air can enter the body through the nose or the mouth.
Pharynx: After entering the nose or mouth, air passes through the pharynx, which is a muscular tube that connects the nasal cavity and the mouth to the larynx and esophagus.
Larynx: The larynx, commonly known as the voice box, is a cartilaginous structure located in the neck that connects the pharynx to the trachea. It also contains the vocal cords, which vibrate to produce sound.
Trachea: The trachea, also known as the windpipe, is a tube that connects the larynx to the bronchi. It is lined with cilia and mucus-producing cells that help to trap and remove foreign particles and microorganisms.
Bronchi: The trachea branches into two bronchi, which lead to the left and right lungs.
Lungs: The bronchi further divide into smaller bronchioles, which terminate in tiny air sacs called alveoli. It is here where the exchange of gases occurs, with oxygen diffusing from the air into the bloodstream and carbon dioxide diffusing from the bloodstream into the air.