Pelvic floor and two others... Flashcards
Obturator internus
O: pelvic surfaces of ilium and ischium; obturator membrane
I: greater trochanter
INNE: nerve to obturator internus (L5, S1, S2)
A: ROT thigh laterally and assists in holding the head of the femur in acetabelum
Piriformis
O: pelvic surfaces of S2-S4 segments; superior margin of greater sciatic notch and sacrotuberous ligament
I:greater trochanter of femur
INNE: anterior rami of S1, S2
Coccygeus
O: ischial spine
I: inferior end of sacrum and coccyx
INNE: branches of S4 and S5 spinal
A: small part of diaphragm that supports viscera; flexes coccyx
Levator Ani
O: body of pubis; tendinosus arch of obturator fascia; ischial spine
I: perineal body, cocyx; anococcygeal ligament walls of prostate or vagina, rectum, andanal canal
INNE: nerve to levator ani (branches S4) inferior and rectal nerve and cocygeal plexus
A: forms most of pelvic diaphragm that helps support pelvic viscera and resists increases in intra-abdominal pressure
External Anal sphincter
O: skin and fascia surrounding anus; coccyx via anococcygeal ligament
I: passes around lateral aspects of the anal canal, insertion into perineal body
INNE: inferior anal rectal nerve, a branch of the pudendal (S2-S4)
A: constricts anal canal during peristalsis, resisting defecation; supports and fixes perineal body and pelvic floor
Bulbospongiosus
Male
O: median raphe on ventral surface of bulb of penis; perineal body
I: surrounds the lateral aspects of bulb of penis and most proximal part of body of penis; inserts into the perineal membrane, dorsal aspect of the corpus spongiosum and corpora cavernosa; and fascia of bulb of penis
Female
O: perineal body
I: passes on each side of the lower vagina; enclosing bulb and greater vestibular gland; inserts into pubic arch and fascia of corpora cavernosa of clitorus
INNE: muscular branch of perineal n. a branch of pudendal nerve (S2-S4)
A: Males; supports and fixes perineal body/pelvic floor; compresses bulb of penis to expel last drops of urine/ semen; assists with an erection by compressing the outflow via deep perineal vein and by pushing blood from the bulb into the body of the penis,
Female; supports and fixes perineal body to pelvic floor; “sphincter” of vagina; assists in erection of the clitoris (and perhaps bulb of vestibule); compresses greater vestibular gland
Ischiocavernosus
O: internal surfaces of ischiopubic ramus and ischial tuberosity
I:embraces crus of penis or clitoris, inserting onto inferior and medial aspects of crus and to perineal membrane
INNE: Muscular deep branch of perineal nerve, a branch of the pudendal nerve (S2-S4)
Superficial transverse perineal
O: internal surfaces of ischiopubic ramus and ischial tuberosity
I: passes along the inferior aspect of the posterior border of the perineal membrane to the perineal body.
INNE: Muscular deep branch of perineal nerve, a branch of the pudendal nerve (S2-S4)
A: supports and fixes the perineal body /pelvic floor to support abdominopelvic viscera and resist increased intrabdominal pressure
deep transverse perineal
O: internal surfaces of ischiopubic ramus and ischial tuberosity
I: passes along the superior aspect of the posterior border of perineal membrane to perineal body and external anal sphincter
INNE: Muscular deep branch of perineal nerve, a branch of the pudendal nerve (S2-S4)
A: supports and fixes the perineal body /pelvic floor to support abdominopelvic viscera and resist increased intrabdominal pressure
external urethral sphincter
O: compresser urethral portion only…
I: surrounds the urethra superior to the perineal membrane; in males it also ascends anterior aspect of prostate; in females, some fibers also enclose vagina (urethrovaginal sphincter)
INNE: Dorsal nerve of the penis or clitoris, the terminal branch of the pudendal nerve (S2-S4)
Psoas Minor
O: sides of T12-L1 vertebrae and intervertebral discs
I: pectinal line, iliopectineal eminence via iliopectinal arch
INNE: anterior rami of lumbar nerves (L1, L2)
A: act conjointly in flexing thigh at hip joint and in stabilizing this joint
Psoas Major
O: sides of T12-L1 vertebrae and intervertebral discs
I: lesser trochanter of femur
INNE: anterior rami of lumbar nerves (L1, L2, L3)
A: act conjointly in flexing thigh at the hip joint and in stabilizing this joint
Iliacus
O: iliac crest:; ilia fossa; ala of sacrum; and anterior sacroiliac liagments
I: tnedon of psoas major, lesser trochanter, and femur distal to it
INNE: femoral nerve (L2, L3)
A: act conjointly in flexing thigh at hip joint and in stabilizing this joint
