Muscles of the perineum Flashcards
Bulbospongiosus
Attachments: in male from median raphe & perineal body (central tendon) to surround bulb of penis; in female from the perineal body to surround vestibular bulb, vaginal orifice & clitoris
Actions: in male empties urethra, maintains erection & contracts during ejaculation; in female constricts vaginal orifice & contributes to erection of clitoris
Innervation: perineal branch of pudendal n.
Blood supply: internal pudendal a.
Ischiocavernosus
Attachments: from ischial tuberosity & ramus to aponeurosis surrounding crus of penis or clitoris
Actions: compresses crus during erection
Innervation: perineal branch of pudendal n.
Blood supply: internal pudendal a.
Sphincter ani externus
Attachments: from perineal body (central tendon) to anococcygeal raphe
Actions: closes anal canal & fixes perineal body
Innervation: inferior rectal branch of pudendal n.
Blood supply: internal pudendal a.
Sphincter urethrae
Attachments: surrounds urethra
Actions: compresses urethra
Innervation: perineal branch of pudendal n.
Blood supply: internal pudenal a.
Compressor urethrae
Attachments: from the ischiopubic ramus to midline passing ventral to the urethra & inferior to the sphincter urethrae (with a variable number of fibers fanning out medially to reach the vagina in females & thus replacing the deep transverse perineus)
Actions: compresses urethra
Innervation: perineal branch of the pudendal n.
Blood supply: internal pudenal a.
Sphincter urethrovaginalis
Attachments: from perineal body, surrounds vagina & urethra to meet contralateral muscle inferior to compressor urethrae
Actions: compresses urethra & vagina
Innervation: perineal branch of the pudendal n.
Blood supply: internal pudendal a.
Deep transverse perineus
Attachments: from ischial tuberosity to perineal body (central tendon)
Actions: fixes perineal body
Innervation: perineal branch of pudendal n.
Blood supply: internal pudendal a.
Superficial transverse perineus
Attachments: from ischial tuberosity to perineal body (central tendon)
Actions: fixes perineal body
Innervation: perineal branch of pudendal n.
Bloody supply: internal pudendal a.
