Pelvis: Pelvic Muscles Flashcards
enumerate pelvic wall muscles
- 2 obturator internus: anterolateral wall of pelivs
- Piriformis: posterior wall of pelvis
Origin of obturator internus
- Inner margins of obturator foramen
- Inner surface of obturator membrane
- inner bony surface between greater sciatic notch & obturator foramen
Insertion of Obturator internus
tendon leaves pelvis through lesser sciatic foramen & inserts in medial surface of greater trochanter of femur
Nerve supply of Obturator internus
nerve to obturator internus
Action of obturator internus
- Lateral rotation of thigh
- its covering is obturator fascia which has white line that gives origin to levator ani + it forms pudendal canal between the fascia and the muscle
Origin of piriformis muscle
front of Middle 3 sacral pieces
Another name for anterior fibers of levator ani
- In male: levator prostate
- In female: sphinctor vaginae (pubovaginalis)
Another name for Middle fibers of Levator ani
Puborectalis
Another name for posterior fibers of levator ani
Iliococcygeus
Origin of anterior fibers of levator ani
inner surface of body of pubic bone
Insertion of anterior fibers of levator ani
aka levator prostate/ sphincter vaginae
* moves backwards and medially
* mainly inserts in perineal body
* some fibers insert in coccyx tip (known as pubococcygeus)
origin of middle fibers of levator ani
white line of obturator fascia
Insertion of middle fibers of levator ani
aka puborectalis:
makes a U-shaped loop around anorectal junction & attaches to fibers of the opposite side
Origin of posterior fibers of levator ani
inner surface of ischial spine
insertion of posterior fibers of levator ani
aka iliococcygeus:
* insert in ano-coccygeal ligament (body/raphe)
* coccyx last 2 pieces
attachement of ano-coccygeal body/raphe
- tip of coccyx
- anal canal
- (sometimes post. fibers of levator ani/ iliococygeus attaches to it)
Nerve supply of levator ani
- upper surface: S4 directly from sacral plexus
- Lower surface: inferior rectal branch of pudendal N (S2,S3,S4)
Action of levator ani muscles
- Supports pelvic viscera in position
- Raises intra-abdominal pressure for straining (defecation, labour, etc)
- Sphincter action of sphincter Vaginae or puborectalis
Pelvic (superior) surface relations of levator ani
- Sup. pelvic fascia
- urinary bladder
- rectum
- in male: prostate
- In female: uterus & vagina
Perineal (inferior) surface relations of Levator ani
Inferior plevic fascia
Anterior relations of Levator Ani
- Male: prostate & uerthra
- female: Urethra & Vagina
posterior relations of levator ani
coccygeus muscle
origin of coccygeus muscle
Ischial spine
insertion of coccygeus
last sacral & 1st coccygeal
Nerve supply of coccygeus
S4 & S5 sacral plexus
Action of coccygeus
supports coccyx during delivery & defecation
