sphincter urethrae
Quick Summary
The sphincter urethrae is a muscular structure that plays a crucial role in controlling urination. It is the most important voluntary control mechanism for expelling urine from the body. This sphincter is part of the urethra, the tube that carries urine from the bladder to the outside.12
The bladder itself has a powerful detrusor muscle for emptying and two muscular sphincters at its exit. The internal sphincter, located at the bladder neck, is under involuntary control, while the external sphincter, composed of striated muscles, is under voluntary control. The external sphincter can maintain continence even if the internal sphincter is not functioning properly. The structure of the urethral wall includes muscle fibers that contribute to its function.34
Ask Britannica AI about this topic
Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.
sphincter muscle…its normal contraction, and the sphincter urethrae is the most important voluntary control of urination. There is also a sphincter in the eye, the sphincter pupillae, a ring of fibres in the iris that contracts the pupil in the presence of bright light. Compare dilator muscle.
Read More…its normal contraction, and the sphincter urethrae is the most important voluntary control of urination. There is also a sphincter in the eye, the sphincter pupillae, a ring of fibres in the iris that contracts the pupil in the presence of bright light. Compare dilator muscle.
Read More
renal systemGeneral description…encircled by a muscle, the sphincter urethrae. The two small bulbourethral glands are on either side of it. The membranous urethra is not firmly attached to the layers of the urogenital diaphragm. The spongy part of the male urethra is that part of the urethra that traverses the penis. It…
Read More…encircled by a muscle, the sphincter urethrae. The two small bulbourethral glands are on either side of it. The membranous urethra is not firmly attached to the layers of the urogenital diaphragm. The spongy part of the male urethra is that part of the urethra that traverses the penis. It…
Read More- renal systemThe bladder
…it contracts, and two muscular sphincters that keep the exit closed at all other times. This smooth muscle coat constitutes the powerful detrusor muscle. At the base of the bladder the region of the bladder neck, or trigone, is demarcated by the two ureteric orifices and the internal opening of…
Read More…it contracts, and two muscular sphincters that keep the exit closed at all other times. This smooth muscle coat constitutes the powerful detrusor muscle. At the base of the bladder the region of the bladder neck, or trigone, is demarcated by the two ureteric orifices and the internal opening of…
Read More