Mention two structural differences between an artery and a vein.
Topic: Artery and vein — structure
Answer
- An ARTERY has THICK, MUSCULAR AND ELASTIC WALLS; a VEIN has THIN, less muscular walls.
- An ARTERY has a NARROW lumen and NO VALVES (except at its origin from the heart); a VEIN has a WIDE lumen and possesses INTERNAL VALVES along its length.
The question says STRUCTURAL differences, so keep to structure — writing that arteries carry blood away from the heart is a FUNCTIONAL difference and does not answer it.
BOTH DIFFERENCES FOLLOW FROM PRESSURE, which is the thing worth understanding: an artery receives blood straight from the ventricle at HIGH pressure, so it needs thick elastic walls to withstand and smooth out the surge. High pressure also means blood cannot flow backwards, so no valves are needed. a vein returns blood at LOW pressure, so thin walls suffice — but low pressure means blood could flow backwards, especially against gravity in the legs, so VALVES are essential to keep it moving one way.
Understand the pressure and you can derive every difference rather than memorising the table.
| Point of difference | Artery | Vein |
|---|---|---|
| Wall | Thick, muscular and elastic | Thin, less muscular |
| Lumen | Narrow | Wide |
| Valves | Absent (except at the origin) | Present throughout |
| Position | Deep-seated | Mostly superficial |