Question

Even when there is no air in it, the human trachea does not collapse due to the presence
A. Cartilaginous rings
B. Chitin rings
C. Bony rings
D. Turgor pressure

Answer 1

Hint: Trachea is also known as windpipe. Air reaches the lungs through the trachea. At the end of the larynx also known as the windpipe, the trachea starts and ends in the lungs.

Complete step by step answer: Humans have a pair of external nostrils opening. Nostrils lead to the nasal chamber through the nasal passage. The nasal chamber opens into the part of the pharynx known as the nasopharynx. The nasopharynx is a common path for air and food. The nasopharynx divides into food pipe and windpipe. Food reaches the stomach through the food pipe also known as oesophagus. The epiglottis flap-like structure present at the glottis part of the larynx prevents the entry of food in the pharynx. Pharynx ends at the glottis part of the larynx. The larynx opens into the trachea. The trachea is a muscular organ consisting of a cartilaginous ring. So if the trachea is muscular then why when there is no air it collapses like a balloon collapses after releasing all air from a balloon. The trachea does not collapse because the trachea circular cartilaginous ring protects the trachea from collapsing when there is no air.
So the correct option is option (A).
Additional Information:
1. Cartilaginous ring: It is made up of cartilage
2. Chitinous ring: It is made up of chitin.
3. Bony ring: It is made up of bones.
4. Turgor pressure: Fluid pressure inside the cell is called turgor pressure

Note: The trachea divide into bronchi. Bronchi undergo repeated divisions to form the secondary and tertiary bronchi and bronchioles ending in the bronchioles. The trachea, bronchi, secondary bronchi, and tertiary bronchi, and bronchioles all consist of a cartilaginous ring. At the terminal of bronchioles, there is a bag-like structure present in the lungs where gas exchange takes place.