Biology / Unit 13 Bio 3211 short lesson, about 20 seconds
Vessel Direction, Not Oxygen Content, Defines Artery and Vein
Captions available
The idea
An artery is defined by carrying blood away from the heart, a vein by carrying blood toward it, per Bio 3203 and 3205 — oxygen content varies by circuit.
In practice
The pulmonary vein carries oxygenated blood toward the heart, matching its vein classification.
Where people slip
"Arteries carry oxygenated blood," per Bio 3209, breaks down exactly at the pulmonary loop this definition explains.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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