The muscle called the urethral sphincter muscle is what constricts in the urethra. The urethral orifice is what is actually constricted by the urethral sphincter.
The assists in emptying the male urethra
With the sphincter muscle, found at the junction of the bladder and the urethra. Involuntary muscles. There is a whole part of the brain that controls involuntary responses and functions. Example:breathing, heart pumping blood.
Autonomic system
SmooTh muscle
In both men and women, the urethra is the tube through which urine is excreted from the urinary bladder to outside the body. Urine flows from the bladder out of the body by way of the urethra when the sphincter muscle is relaxed. The urethral sphincter muscle is at the base of the bladder and controls the release of urine from the bladder into the urethra, which then flows out of the meatus (opening at the end of the urethra) when urinating. The urethra is approximately 1 1/2 inches long in females and around 8 inches long in males. The urethral meatus is located at the tip of the penis in men and between the clitoris and vaginal opening in women. In males the urethra also carries semen from the ejaculatory duct outwards through the penis. The semen is directed from the reproductive organs through the vas deferens tube for semen that intersects with the urethra at the prostate gland. A valve there at the base of the urethra directs the flow of either urine or semen through the urethra and out of the meatus.
Smooth muscle surrounding the bladder pushes urine out of the urethra.
heart
The heart.
No the bladder has a sphincter muscle to control flow but past that is clear sailing.
The organ system that controls the movement of the muscle system is known as the skeletal system.
he has a muscle which controls it
The heart? /shrugs