Question

Even when there is no air in it, human trachea does not collapse due to the presence of:
(a) Cartilaginous rings
(b) Chitinous rings
(c) Bony rings
(d) Turgor pressure

Answer 1

Human trachea, also known as windpipe, is defined as a tube which connects the larynx with the bronchi of the lungs. It is surrounded by many ring-like structures that are strong and very flexible which support the trachea.

Complete answer:
Human trachea does not collapse due to the presence of a cartilaginous ring when there is no air in it. The top of the trachea consists of the cricoid cartilage which gets attached to the larynx. Several cartilaginous rings are present in the trachea which is joined together through ligaments and tracheal muscles which are present at their ends. During the swallowing of the food, the epiglottis closes the opening to the larynx. The trachea has an inner diameter of 1.5 centimetres with 11 centimetres of length and is wider in males as compared to females. The hyaline cartilage is present around the trachea and these rings are connected to the ligaments. It is the part of the respiratory system which helps the air to pass through the alveoli to and from the lungs and transmits oxygen by removing carbon dioxide to the body.
Chitinous rings: The trachea constitutes three layers which cover the wall of the trachea with the outer basement membrane and the middle membrane which constitutes of the thick epithelium. The inner membrane is lined by the intima which is known as the chitinous layer.
Bony rings: The trachea institutes many rings which are made up of cartilage and are mostly C-shaped which supports the trachea and allows it to move.
Turgor pressure: This pressure creates a force on the cell against the cell wall which is exerted by the osmotic flow of the water and causes the cell turgidity through a selectively permeable membrane.

So, the correct answer is 'Cartilaginous rings'.

Note:
A person named Thomas was born without tracheae and the condition is known as tracheal agenesis which is rare among people. The measurement of the lifespan of an infant who is born without a trachea is in minutes.