Download pelvic bones

PELVIC BONES
• Hip bone
• Sacrum
• coccyx
1
PELVIC MUSCLES
piriformis
obturator internus
levator ani
coccygeus
Muscle
Origin
Insertion
Action
piriformis
anterior surface of
sacrum
greater trochanter
of femur
laterally rotates and
abducts thigh
obturator internus
the internal surface of
the obturator
membrane and
margin of the
obturator foramen
greater trochante
laterally rotates and
abducts the thigh
levator ani
posterior surface of
the body of the pubis,
fascia of the obturator
internus m., ischial
spine
perineal body,
anococcygeal
body and coccyx
elevates the pelvic
floor
coccygeus
ischial spine
side of the coccyx
and lower sacrum
elevates the pelvic
floor
•
Levator ani is the main muscle of the pelvic floor. It forms a funnel-shaped diaphragm in the pelvis
between the lateral hip walls, the pubis anteriorly and the coccyx posteriorly. It is traversed by
different structures in each sex:
•
males:
•
•
urethra
•
anal canal
females:
•
urethra
•
vagina
•
anal canal
•
Often, levator ani is considered as several separate muscle parts:
•
pubovaginalis
•
iliococcygeus
•
pubococcygeus
•
puborectalis
•
However they have common features:
•
origin: from a tendinous arch between the pubis and ischial spine on the internal surface of the
pelvis
•
insertion:
•
perineal body
•
external wall of anal canal
•
anococcygeal ligament
•
coccyx