Appendicular Skeleton - Bones of the Pelvic Girdle
arcuate line
a ridge of bone that runs inferiorly and anteriorly from the auricular surface of the ilium; visible in the medial view
lesser sciatic notch
a small notch located inferior to the ischial spine
pubic arch of male pelvis
angle is more acute
bone thickness of male pelvis
bones are heavier and thicker, markings are more prominent
bone thickness of female pelvis
bones are lighter, thinner, smoother
pubic arch of female pelvis
broader angel, more rounded
greater sciatic notch
deep notch located superior to the ischiac spine; allows the sciatic nerve to enter the thigh; upper border and deep part of lower border belong to ilium; lower border, nearest ischial spine, belongs to ischium
acetabulum
deep socket where the ilium, ischium, and pubis fuse; receives the head of the thigh bone; visible from the lateral view
obturator foramen
foramen enclosed by a bar of bone formed by the rami of the pubis and ischium; allows blood vessels and nerves to pass
pubic arch
formed by the convergence of the inferior rami of the ischium and pubis on either side, below the pubic symphysis
inferior pubic ramus
inferior extension of the body of the pubis; articulates with the ischium
sacroiliac joint
joint in between the sacrum and the ilium; joined by strong ligaments
ischial spine
located superior to the ischial tuberosity and projects medially into the pelvic cavity
symphysis pubis
midline cartilaginous joint uniting the superior rami of the left and right pubic bones
sacrum of male pelvis
narrow, longer, sacral promontory projects anteriorly
ischial tuberosity
rough projection that receives the weight of our body when we are sitting; most visible on lateral and posterior views
iliac fossa
shallow depression below the iliac crest; forms the internal surface of the ilium; visible in anterior & medial views
pelvis
structure formed by the ossa coxae, sacrum, and coccyx
superior pubic ramus
superior extension of the body of the pubis; process of bone extending between body of pubis and acetabulum
iliac crest
thick superior margin of bone (hands on hip)
structure of male pelvis
tilted less forward; adapted for support of a male's heavier build and stronger muscles; cavity of the true pelvis is narrow and deep
structure of female pelvis
titled forward; adapted for childbearing; true pelvis defines the birth canal; cavity of the true pelvis is broad, shallow, and has a greater capacity
sacrum of female pelvis
wider, shorter, sacrum is less curved
os coxa
(2, pelvic girdle) form the hip; large, heavy, irregular bones; attach to the axial skeleton; ability to bear weight is more important than flexibility (more so than in pectoral girdle) fused bones: ilium, ischium, pubis Markings: acetabulum, obturator foramen
ischium
(os coxa) "sit down bone" parts: ischial tuberosity, ischial spine, lesser sciatic notch
pubis
(os coxa) 2 pubic bones meet at pubic crest; inferior and anterior part of the os coxa parts: superior pubic ramus, inferior pubic ramus, symphysis pubis, pubic arch
ilium
(os coxa) large bone; "hands on hip" parts: iliac crest, iliac fossa, arcuate line, sacroiliac joint, greater sciatic notch
bones in the pelvic girdle
2 os coxa (and the sacrum)