Question

multiple select question
select all that apply
what are functions of the endothelium lining a blood vessel?
□ it provides a smooth surface for blood flow.
□ it secretes substances that stimulate vessel dilation or constriction.
□ it prevents inappropriate blood clotting.
□ it provides blood vessel elasticity.
□ it constricts or dilates to control blood flow.

Explanation:

The endothelium is a single - layer of cells lining blood vessels. It creates a smooth surface for blood to flow over, secretes vasoactive substances for vessel dilation/constriction, and has anti - clotting properties. Blood vessel elasticity is mainly due to connective tissues like elastin, and the endothelium doesn't directly constrict or dilate to control blood flow (smooth muscle does that).

Answer:

• It provides a smooth surface for blood flow.
• It secretes substances that stimulate vessel dilation or constriction.
• It prevents inappropriate blood clotting.