Male urethral sphincters

Males have two sphincters:

1. Bladder internal/neck sphincter, smooth muscle is continuous with the detrusor muscle and is under involuntary control or autonomic control; the function of this sphincter is to keep the bladder closed at the time of ejaculation.

2. External bladder neck sphincter, striated/skeletal muscle at the base of the prostate and is under voluntary control of the somatic nervous system. This muscle can be exercised and will strengthen with pelvic floor exercises. ^{Figure 2.3: Male bladder showing the position where the ureters enter the bladder, the trigone and the bladder sphincters.}