New News Biology #15

Gas Exchange & Lungs

Cellular Respiration = Needs Oxygen (brought in by the lungs)

Structure of the respiratory system:

Air goes in through mouth

Down the windpipe

Into bronchi (part of lungs)

& further branch out into the bronchioles

Reach the alveoli (sight of gas exchange)

Alveolus

• very large surface area

• single layer of cells

• next to it is the bloodstream

It is adapted so that the rate at which Co2 & oxygen diffuse across is increased

Trivia Fact: ‘Breathing Rate’ = No. Of Breaths ÷ No. Of Minutes