6) List one function of each of the following :
a) Lungs
b) Trachea
c) Diaphragm
d) Larynx
e) Bronchi
f) Bronchioles
g) Alveoli

Dear Student,
1. a It is a respiratory organ.
b) To supply oxygen to the blood and releasing carbon dioxide.

In insects gaseous exchange occurs by means of a systems of tubes called the tracheal system. Pairs of holes called spiracles are found on the insects body, these holes lead into air filled sacs, extending from these are the branched tubes called tracheae (singular is trachea).

In humans the air after passing through the nasal passage reaches a structure called as trachea which splits into 2 bronchi and enters into the two lungs of the body.

It helps to provide the passage for air and respire effectively.

3. The diaphragm is an thin muscular sheet that forms the floor of the chest cavity. The up and down movement of the diaphragm causes a change in the size of the chest cavity that is necessary for breathing.

4. Bronchi are the branches of trachea (wind pipe) which enter the lungs. Trachea divides into two branches, each of which which enter one lung. Further they divide multiple times to form fine tubes called bronchioles.

Bronchus (plural- bronchi) is a connecting link between lungs & trachea. Each lung has one bronchus which conducts air to lungs. The bronchus further branches into many bronchioles.


  • When we inhale, the membranes of alveoli inside the lungs get blown up like balloons so that the surface area increases. Increase in surface area enhances better gas exchange.
  • The walls of alveoli are covered by extensive network of blood vessels or capillaries in which oxygen from alveoli dissolves and are carried by the blood to the heart for pumping. In the same way carbon dioxide from the body cells are carried by the blood capillaries to the alveoli from where it goes out of the body.

Hope this information will clear your doubts about topic.

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