GAS EXCHANGE IN THE LUNGS Flashcards Preview

BIOLOGY - EXCHANGE AND TRANSPORT SYSTEMS > GAS EXCHANGE IN THE LUNGS > Flashcards

Flashcards in GAS EXCHANGE IN THE LUNGS Deck (7)
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1
Q

How many alveoli are there in each lung

A

300 million

2
Q

Why is gas diffusion between alveoli and blood very rapid (6)

A

1) red blood cells are slowed as they pass trhough pulmonary capillaies - allowing time for diffusion
2) distance between alveolar air and red blood cells is reduced (as red blood cells flattened against capillary walls)
3) walls of alveoli and capillaries are very thin
4) alveoli and pulmonary arteries have large total SA
5) steep concentration gradient of gases is maintained

3
Q

How is a steep concentration gradient maintained

A

breathing constantly ventilates lungs, heart constantly circulates blood around alveoli, constant blood flow through pulmonary capillaries

4
Q

What are the alveoli surrounded by a network of in the lungs

A

capillaries

5
Q

What is the path of 02 through the lungs

A

into lungs, into alveoli, diffuses out of alveoli, across alveolar epithelium and capillary endothelium, into haemoglobin in the blood

6
Q

What are cappilary endothelium

A

type of epithelium that forms the capillary wall

7
Q

What does correlation not guarantee

A

causation (casual relationship)