Bony & Ligamentous pelvis
Functions of pelvis
- Protects pelvic viscera
- Supports weight of body
- Provides attachment foir muscles
- Supports birth canal in female
Components
- All 3 bones fuse at acetabulum "vinegar cup" which forms socket for femoral head
- Pelvis tiled in erect position so that plane of inlet is at an angle of 60' to the horizontal
- Os innominatum
- Ilium
- Ischium
- Pubis
- Sacrum
- Coccyx
Ligaments and Joints of the Pelvis
- Symphysis pubis -
- cartilaginous joint between pubic bones
- Pubic bone covered by layer of hyaline cartilage
- Sacroiliac joints
- Articulations between auricular surfaces of sacrum and ilium on each side
- Synovial joints
- Held together by anterior + posterior sacroiliac ligaments (the strongest ligaments in the body)
- Sacrotuberous / sacrospinal ligaments
- Form lesser and greater sciatic foramen
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Sacrum
- Made up of 5 fused vertebrae, roughly triangular
- Anterior border = sacral promotry
- Anterior aspect: central mass + 4 anterior sacral foramina (transmits 4 upper sacral anterior primary rami)
- Lateral masses of sacrum forms fan-shaped "ala"
- Posteriorly: sacral canal (continuation of vertebral canal) terminates at sacral hiatus + 4 posterior sacral foramina
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Coccyx
- Made up of 3-5 fused vertebrae
- Represents tail of primitive animals
