bio - gas exchange

BREATHING/VENTILATION: the process of moving air in (inhalation) and out (exhalation) of the lungs.

- ventilation is made possible by action of muscles.: diaphragm & intercoastal muscles

INHALATION
diaphragm contracts/flattens
intercoastal muscles - contract
rib cage - moves upward & outward
volume of chest cavity - increases
pressure of == - decreases
air movement - forced inside lungs

EXHALATION
diaphragm relaxes/becomes dome shaped
intercoastal -…