Question

Characteristic of smooth muscle fibres are

• A. Spindle-shaped, unbranched, unstriated, uninucleate and involuntary
• B. Spindle-shaped, unbranched, unstriped, multinucleate and involuntary
• C. Cylindrical, unbranched, unstriped, multinucleate and involuntary
• D. Cylindrical, unbranched, striated, multinucleate and involuntary

Answer 1

Answer: (A)

Characteristics of smooth muscle fibres:

• Cells range from 5 to 10 $\mu \text{m}$ in diameter and 30 to 200 $\mu \text{m }$ in length
• Spindle-shaped
• Single, centrally located nucleus.

Smooth muscle tissue occurs within almost every organ, forming sheets, bundles or sheaths around other tissues. Smooth muscle differs from both skeletal and cardiac muscle tissues in structure and function. Sarcomeres or myofibrils are not present (therefore not striated, i.e., smooth).