Pelvic outlet
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| Pelvic outlet | |
|---|---|
 | |
| Diameters of inferior aperture of lesser pelvis (female). | |
| Muscles of the female perineum. | |
| Latin | apertura pelvis inferior |
| Gray's | subject #58 240 |
| Dorlands/Elsevier | a_51/12144712 |
The lower circumference of the lesser pelvis is very irregular; the space enclosed by it is named the inferior aperture or pelvic outlet.
Contents |
[edit] Boundaries
It has the following boundaries:
- behind: by the point of the coccyx
- laterally: by the ischial tuberosities
[edit] Notches
These eminences are separated by three notches:
- one in front, the pubic arch, formed by the convergence of the inferior rami of the ischium and pubis on either side.
- The other notches, one on either side, are formed by the sacrum and coccyx behind, the ischium in front, and the ilium above; they are called the sciatic notches; in the natural state they are converted into foramina by the sacrotuberous and sacrospinous ligaments.
[edit] In situ
When the ligaments are in situ, the inferior aperture of the pelvis is lozenge-shaped, bounded as follows:
- in front, by the pubic arcuate ligament and the inferior rami of the pubes and ischia
- laterally, by the ischial tuberosities
- behind, by the sacrotuberous ligaments and the tip of the coccyx.
[edit] Additional images
Articulations of pelvis. Anterior view. |
Articulations of pelvis. Posterior view. |
| Pelvis/pelvic cavity: sacrum, coccyx, hip bone |
|---|
| Ilium: Arcuate line - Wing - gluteal lines (Posterior, Anterior, Inferior) - Fossa - Tuberosity - Crest - iliac spines (Anterior superior - Anterior inferior - Posterior superior - Posterior inferior)
Ischium: Body (Ischial spine, Lesser sciatic notch) - Superior ramus (Tuberosity of the ischium) - Inferior ramus Pubis: Superior ramus (Pubic tubercle, Pubic crest, Obturator crest) - Inferior ramus (Pectineal line) Compound: Obturator foramen - Acetabulum - Acetabular notch - Greater sciatic notch - Iliopectineal eminence - Ischiopubic ramus - Pubic arch - Lesser pelvis (Pelvic inlet, Pelvic brim, Pelvic outlet) - Greater pelvis |
