GENERAL INFORMATION
The sphincter urethrae membranacea is a muscle located in the perineum. It is part of the deep layer of the pelvic floor muscles and plays a crucial role in maintaining continence by controlling the opening and closing of the urethra.
ORIGIN
It originates from the inferior pubic ramus as well as the ischial ramus.
INSERTION POINT
This muscle inserts into the central tendon of the perineum.
MAJOR ARTERIES
The sphincter urethrae membranacea receives its blood supply from branches of the internal pudendal artery.
NEURAL INNERVATION
The sphincter urethrae membranacea is innervated by the pudendal nerve (S2-S4), which provides sensory and motor innervation to the perineum.
TRIGGER POINT
Trigger points in this muscle can cause pain and discomfort in the perineal region.
CONCENTRIC FUNCTION
During contraction, the sphincter urethrae membranacea muscle tightens to close the urethra and maintain continence.
ECCENTRIC FUNCTION
The eccentric function of the sphincter urethrae membranacea muscle occurs during relaxation. It allows for the opening of the urethra to pass urine.
ISOMETRIC FUNCTION
The sphincter urethrae membranacea muscle can contract isometrically to provide stability and support to the perineum and pelvic floor muscles.
RELATED MUSCLE SCIENTIFIC NAMES
- External urethral sphincter: Controls the flow of urine by contracting and relaxing around the urethra.
- Sphincter urethrae: Another name for the external urethral sphincter, emphasising its role in urethral control.
ANTAGONIST MUSCLES
- Bulbospongiosus: This muscle helps expel the last drops of urine in males and contributes to erection and ejaculation.
- Ischiocavernosus: Assists in maintaining erection by compressing the veins of the penis or clitoris.
COMMON INJURIES
- Perineal tears during childbirth: Tears in the perineum that can damage the muscle.
- Strain or sprain of the sphincter urethrae membranacea muscle: Overuse or injury causing pain and dysfunction.
- Perineal trauma from accidents or falls: Impact injuries that can affect the sphincter urethrae membranacea and surrounding tissues.
EXERCISES
- Kegel exercises: Strengthen the pelvic floor muscles, including this muscle, through contraction and relaxation.
- Pelvic floor muscle exercises: Improve perineal muscle strength and control, enhancing overall pelvic health.
- Squats: Engage the perineal muscles and improve pelvic stability and strength.
STRETCHES
- Butterfly stretch: Stretches the inner thighs and perineal muscles, enhancing flexibility.
- Happy baby pose: Releases tension in the perineum and lower back, promoting relaxation.
- Seated forward fold: Stretches the hamstrings and perineal area, relieving tension.
- Child’s pose: Stretches the perineum and relaxes the pelvic floor muscles, aiding in overall muscle relaxation.