The structure which prevents the entry of food into the respiratory tract is

Select the correct option based on the number of structures in the human respiratory system:
$I$ - Trachea,$II$ - Terminal bronchioles,$III$ - Secondary bronchi,$IV$ - Tertiary bronchi

What is the length of the pharynx (in $cm$)?

The covering of the lungs in humans is known as....

Which is a common passage for swallowing food and breathing?

Lungs have a large number of narrow tubes called