[Campbell Biology P.978] Which feature depicted in Figure 42.9 is exclusively present in vei... | Practice Question

Which feature depicted in Figure 42.9 is exclusively present in veins among the major blood vessel types shown, contributing to their specific function?

  • A: Endothelium lining the lumen.
  • B: A prominent smooth muscle layer.
  • C: The presence of a valve.
  • D: An outer layer of connective tissue.

Explanation

Figure 42.9 clearly shows a 'Valve' explicitly within the vein diagram, and the text states that 'Unlike arteries, veins contain valves, which maintain a unidirectional flow of blood despite the low blood pressure in these vessels.' The other options are present in multiple types of vessels.