Problem 8 - Biology: The Dynamic Science

Question

Characteristics of veins and venules are: a. thick walls. b. large muscle mass in walls. c. a large quantity of elastin in the walls. d. low blood volume compared with arteries. e. one-way valves to prevent backflow of blood.

Step-by-Step Solution

Answer

The correct statement is e. one-way valves to prevent backflow of blood.

Step 1: Understanding the statements

The first statements a, b, c refer to the anatomy of the blood vessels. Specifically, they refer to the muscle mass and elasticity of the vessel walls. Veins and venules don't generally have thick walls nor large muscle mass, and while they contain some elastin, it's not a large quantity.

Step 2: Cross-checking with known facts

The statement d indicates that veins and venules have a lower blood volume compared with arteries. However, it is known that veins hold about 70% of the blood volume in the body acting as a blood reservoir. Hence, this statement is incorrect.

Step 3: Judging the final statement

Veins, due to the low pressure of blood, have one way valves that allow blood to flow towards the heart but prevent its backflow. This makes option e correct as it mentions these one-way valves.