External sphincter of male urethra in human being is found in the membranous part of the urethra.

Anatomy of male urethra:
The male urethra is a tube-like structure that extends from the bladder neck to the external urethral orifice at the tip of the penis. It can be divided into four parts:

1. Prostatic part: It is the widest and most dilatable part of the urethra and passes through the prostate gland.

2. Membranous part: It is the shortest and narrowest part of the urethra and passes through the urogenital diaphragm.

3. Bulbar part: It is the part of the urethra that lies between the membranous part and the penile urethra.

4. Penile part: It is the part of the urethra that passes through the penis and opens at the external urethral orifice.

External sphincter of male urethra:
The external sphincter of the male urethra is a striated muscle that surrounds the membranous part of the urethra. It is responsible for voluntary control of urine flow. It is innervated by the pudendal nerve and is under conscious control. The external sphincter contracts during the storage phase of micturition, keeping the urethra closed and preventing urine from leaking out. It relaxes during the voiding phase, allowing urine to flow out of the bladder and through the urethra.

Clinical significance:
Damage to the external sphincter can result in urinary incontinence, which is the involuntary leakage of urine. This can be caused by trauma to the urogenital diaphragm during pelvic surgery or childbirth, or by neurological conditions that affect the pudendal nerve, such as spinal cord injury or multiple sclerosis. Treatment options for urinary incontinence include pelvic floor exercises, medication, and surgery.

Conclusion:
The external sphincter of the male urethra is located in the membranous part of the urethra and is responsible for voluntary control of urine flow. Damage to this muscle can result in urinary incontinence, which can have a significant impact on quality of life.

The male external sphincter muscle of urethra (sphincter urethrae): located at inferior to the prostate (at the level of the membranous urethra) in males is a secondary sphincter to control the flow of urine through the urethra.hope its help thanks for asking question