Question

select the option which gives correct function or characteristic of the four part of human respiratory system.
A. alveoli: thin-walled sac like structures for exchange of gases.
B. Diagram: it is pulled up when we breathe in.
C.Trachea: it is supported by Bony rings for conducting inspired air.
D. Ribs: When we breathe out, ribs are lifted.​

Answer 1

Answer:

A. alveoli: thin-walled sac like structures for exchange of gases.

Answer 2

The option which gives correct function or characteristic of the four part of human respiratory system is A. alveoli: thin-walled sac like structures for exchange of gases.

• Alveoli are very small bag like structures that are present on the terminating point of the bronchioles . They help in exchange of gases . Hence, correct answer is option A.
• The diaphragm contracts during the time of inspiration.
• The trachea is supported by cartilaginous rings not bony rings. It's supported by C shaped incomplete cartilaginous rings in order to avoid collapsing. Hence, option is incorrect.
• Breathing out or expiration the diaphragm reach the state of relaxation. All the muscles reach in normal position. Hence, our ribs are not lifted up in the process. So, option D is incorrect too.