Page 381 - Primary Six Notes

Adaptations of air sacs Ethmoid Sinuses

Tongue
to their function Throat 1 r •v

 They have walls to all Trachea / 9L
■Li
diffusion take place. /s' vK
i
A,
Bronchi > r ´
f
 They are surrounded vAJ i \±-
by a network of capil- ilk
laries which bring car-

bon dioxide and take <M\ Pleura Alveoli

Bronchioles
oxygen.

 They are many in num- 10. Lungs

ber. The lungs are the main organs of

the respiration system. In the lungs

oxygen is taken into the body and carbon dioxide is breathed

out. The main function of the lungs is to exchange carbon diox-

ide for oxygen and vice versa.

11. Diaphragm

The diaphragm is a dome-shaped muscle at the bottom of the

lungs.

Upon inhalation, the diaphragm contracts and flattens and

the chest cavity enlarges. This contraction creates a vacuum,

which pulls air into the lungs. Upon exhalation,

the diaphragm relaxes and returns to its domelike shape, and

air is forced out of the lungs.