Alveoli

what are the walls of the alveoli called

gas exchange surface

what are closely wrapped around outside of alveoli

tiny capillaries

how is alveoli efficient for gas exchange (3)

-thin walls

-large surface area

-moist lining for dissolving gases

explain why the previous factor are efficient

-thin walls: fast diffusion

-large surface area: increase contact between air and blood

-moist lining: gases dissolved in water aids diffusion

ventilation

movement of air in and out of the lungs by breathing movement

What elements are found in air (3)

oxygen

carbon dioxide

water vapour

percentages of inspired elements

oxygen: 21%

carbon dioxide: 0.04%

water vapor: <1%

percentage of expired elements

oxygen: 16%

carbon dioxide: 4%

water vapor: 3%

breathing

using intercostal muscles in the diaphragm to change the volume of the thorax to draw in and push out air in lung