Biology / Unit 13 Bio 3207 short lesson, about 20 seconds
Capillary Structure and Exchange
Captions available
The idea
A capillary wall is a single cell layer thick, allowing direct exchange of gases, nutrients, and waste between blood and tissue across the shortest distance.
In practice
Oxygen and nutrients diffuse out into tissue while carbon dioxide and waste diffuse in, at the same stretch.
Where people slip
Only capillaries exchange with tissue directly — arteries and veins mainly transport blood.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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