Question

What type of muscle comprises the internal sphincter of the urethra?

Options

• Both smooth and striated muscle fibres

• Cardiac muscle fibres

• Smooth muscle fibres

• Striated muscle fibres

Answer 1

The internal sphincter of the urethra is composed of smooth muscle fibres and is located at the beginning of the urethra. It is involuntary and helps control the initial flow of urine and semen.