Compare7 marksChallenge
Two blood vessels from a mammal are described below:
Vessel X:
- Thick wall composed of three distinct layers (tunica intima, media, adventitia).
- Tunica media contains many layers of elastic fibres and smooth muscle cells.
- Lumen is narrow and circular.
- No valves present.
Vessel Y:
- Thin wall with the same three layers but less developed.
- Tunica media contains few elastic fibres and smooth muscle cells.
- Lumen is wide and irregular in shape when not distended.
- Contains semilunar valves at intervals.
Using information from the descriptions, compare the structures of Vessel X and Vessel Y, and explain how each structural feature is adapted to the vessel's function in the circulatory system.