Does oxygenated blood always travel in arteries?

Short answer: no. And if you answered yes confidently, you're in excellent company — this is one of the most confidently-held wrong answers in first-year physiology, which is exactly why examiners love it.

The misconception: arteries carry oxygenated blood, veins carry deoxygenated blood.

The truth: arteries carry blood away from the heart; veins carry blood toward it. Direction defines them — oxygen content is just the usual passenger, not the definition.

The two exceptions every exam knows:

The pulmonary arteries carry deoxygenated blood — away from the right ventricle, toward the lungs to collect oxygen. The pulmonary veins carry the freshest, most oxygenated blood in the entire body — from the lungs back to the left atrium.

Why the misconception is dangerous, not just wrong: it quietly breaks your understanding of fetal circulation (where the umbilical vein carries the oxygenated blood), of congenital heart disease, and of why a pulmonary embolism behaves the way it does. Definitions built on the wrong axis collapse exactly when questions get clinical.

The one-line repair to store: vessels are defined by direction, not by cargo.

Want to check whether this one was hiding in your own head with false confidence? This is precisely the kind of confident-wrong the Misconception Radar on Meyshan Med is built to hunt — its probes go live one by one as each is medically reviewed, because on this site nothing tests students before a human has checked it.

Medical review status: this article follows Meyshan Med's review process and carries its pending-review banner until review completes. Sources: standard physiology references; exact citations attach at review. Educational content — not clinical guidance.

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