Which of the following is NOT a function of smooth muscle tissue?

• A. Regulating the diameter of blood vessels
• B. Pumping blood throughout the body
• C. Controlling the contraction of the urinary bladder
• D. Moving food through the digestive tract

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the characteristics of smooth muscle tissue. Smooth muscle is an involuntary, non-striated muscle type found in the walls of hollow organs such as blood vessels, the digestive tract, and the urinary bladder. It is responsible for functions like regulating the diameter of blood vessels, moving food through the digestive tract, and controlling the contraction of the urinary bladder.
2. Step 2: Compare the functions listed in the question with the known roles of smooth muscle tissue. Smooth muscle tissue is involved in regulating blood vessel diameter (vasoconstriction and vasodilation), moving food through the digestive tract (peristalsis), and controlling the contraction of the urinary bladder (to aid in urination).
3. Step 3: Identify the function that does not align with smooth muscle tissue. Pumping blood throughout the body is a function of cardiac muscle tissue, not smooth muscle tissue. Cardiac muscle is specialized for rhythmic contractions to maintain blood circulation.
4. Step 4: Recognize that smooth muscle tissue does not have the structural or functional properties required for pumping blood. Cardiac muscle tissue, found exclusively in the heart, is uniquely adapted for this role due to its striated appearance and intercalated discs that facilitate synchronized contractions.
5. Step 5: Conclude that the correct answer is 'Pumping blood throughout the body,' as this is not a function of smooth muscle tissue but rather of cardiac muscle tissue.