Bones and Joints of the Pelvic Girdle

Sex based on pelvic features: Ischial tuberosities

-Female pelvis: everted -Male pelvis: inverted

Sex based on pelvic features: Acetabulae

-Female pelvis: farther apart and smaller -Male pelvis: closer together and larger

Sex based on pelvic features: Coccyx

-Female pelvis: straighter, more movable -Male pelvis: curved anteriorly, mess movable

Sex based on pelvic features: Pubic arch

-Female pelvis: wide angle -Male pelvis: narrow angle

Sex based on pelvic features: Pelvic inlet shape

-Female pelvis: wider and oval-shaped -Male pelvis: narrower and heart-shaped

PUBIS

-anterior portion

Ischial ramus

-anterior side -articulates with the pubis

Pubic symphysis (symphyseal surface)

-bodies of the two pubic bones meet at a *fibrocartilage pad* called the pubic symphysis

Coxal bone

-each coxal bone is also known as the hemipelvis -3 fused bones in each: ilium, ischium, pubis

3 bones of the coxal (hip) bones

-ilium, ischium, pubis -all 3 come together to form a deep socket, called the *acetabulum*, which forms the hip joint with the femur -ischium and pubis meet to form a large hole called the *obturator foramen*, which is covered with a membrane and allows only smalll blood vessels and nerves to pass through

ILIUM

-largest of the 3 bones

Acetabulum

-lateral side -ilium, ischium, & pubis come together to form this deep socket -forms the hip joint with the femur

Iliac crest

-ridge of the ala

Orientation of the Pelvis

-sacrum: looks like a shield, smooth surface faces anterior, points inferior -coccyx: pointed beak faces inferiorly -coxal bones: large hole located at inferior aspect of bone

Coccyx

-tailbone

Pelvic Girdle

-two coxal (hip) bones connected by the public symphysis *each coxal bone: ilium, ischium, and pubis fused together -sacrum -coccyx

Sacro-iliac Joint

-where *sacrum* and *ilium* meet -joint type: gliding joint -movement: gliding movements

Obturator foramen

-where the ischium and pubis meet -covered with a membrane and allows only small blood vessels and and nerves to pass through

Greater sciatic notch

allows the greater sciatic nerve to pass from the pelvis to the thigh

ISCHIUM

makes up the posteroinferior pelvis

Iliac fossa

medial side of the ala; concave

Ischial tuberosity

on lateral side