Other things to remember:

Breathing in (inhalation): When you breathe in it:

-         increases the space (volume) in your chest cavity

-        reduced pressure

Breathing out (exhalation):

-        space in the chest cavity gets smaller

-        air is forced out of your lungs

-        increased pressure

Ventilation: the inhalation and exhalation of air (respiratory system)

Gas exchange: the delivery of oxygen from the lungs to the blood stream and the elimination of carbon dioxide from the bloodstream to the lungs

Gas exchange happens at the alveoli and at respiring cells where carbon dioxide and oxygen diffuse in/out of the blood

Difference between inhaled air and exhaled air:

-        more water (higher water content) in exhaled air

-        exhaled air is warmer

-        less oxygen in exhaled air

-        more carbon dioxide exhaled

Exercise:

-        increases the size of the lungs

-        increases gas exchange for more efficient breathing

Energy can be used for:

-        heat

-        growth

-        repair

-        muscle contraction