Male vs Female Pelvis Anatomy Quiz & Flashcards

Study Notes

Platypelloid Pelvis
- Comprises 2% of pelvis types.
- Flattened at the inlet with a prominent sacrum; sacral promontory is forward.
- Wide subpubic arch but prominent ischial spines.
- Predominantly favors transverse fetal presentations.
Anthropoid Pelvis
- Seen in 24% of white women and 41% of black women.
- Oval shape at the inlet, narrow with a long axis.
- Slight narrowing of the subpubic arch.
- Tends to favor occiput posterior fetal presentations.
Android Pelvis
- Found in 33% of white females and 16% of black females.
- Triangular shape at the inlet with a narrowed subpubic arch.
- Larger fetuses struggle due to blocked normal areas for rotation and extension; smaller ones may still pass through.
- Known as male or funnel-shaped pelvis; deeper compared to female pelvis.

Male Pelvis
- Pelvic inlet: heart-shaped; narrower than female.
- Pelvic cavity: deeper, narrower; pelvic outlet smaller.
- Pubic arch: narrower.
- Long and narrow structure.
Female Pelvis
- Pelvic inlet: oval, transversely wider.
- Pelvic cavity: roomier and shallower than male.
- Pelvic outlet: larger and more rounded.
- Pubic arch: wider and more rounded.
- Short and wide structure.

Pelvic Floor
- Supports pelvic viscera, formed by the pelvic diaphragm and associated fascia.
- Divides the pelvic cavity from the perineum.
Pelvic Diaphragm
- Composed of levatores ani and coccygeous muscles.
- Incomplete anteriorly to allow passage of urinary and reproductive structures.

Sacrum
- Composed of five fused vertebrae forming a wedge-shaped bone.
- Articulates with the 5th lumbar vertebra at the upper border and fuses with the coccyx at the inferior border.
- Forms the sacroiliac joint with the iliac bone.
- Sacral promontory serves as an important obstetric landmark.
Coccyx
- Formed by four fused vertebrae, resulting in a small triangular bone.
- Articulates with the base of the sacrum.

Sacral Hiatus
- Formed when laminae of the 5th or sometimes 4th vertebra do not fuse.
- Houses the anterior and posterior roots of spinal nerves.
Obturator Foramen
- Formed by the hip bone and other ligaments; covered by obturator membrane for nerve passage.