Pelvis anatomy in 3D
The bony pelvis is a ring formed by the two hip bones in front and at the sides and the sacrum and coccyx behind. It carries the weight of the upper body to the lower limbs, protects the pelvic organs and gives attachment to the muscles of the trunk, hip and pelvic floor. In this free 3D model you can compare a male and a female pelvis and see the three bones that make up each hip bone.
Image: Cogni Anatomy · CC BY 4.0 · Sources: BodyParts3D- Each hip bone forms from 3 bones, ilium, ischium and pubis, which meet and fuse at the acetabulum
- 3 joints close the pelvic ring: 2 sacroiliac joints and the pubic symphysis
- The pelvic brim divides the greater (false) pelvis above from the lesser (true) pelvis below
- The subpubic angle is narrower in males (about 50–60°) than in females (about 80–90°)
- The sacrum is 5 fused vertebrae; the coccyx usually 4 (3–5) small fused vertebrae
Structure of the pelvis
The ilium forms the broad upper wing ending in the iliac crest; the ischium forms the lower back part with the ischial tuberosity; the pubis forms the front, and the two pubic bones meet at the pubic symphysis. All three meet at the acetabulum, the socket of the hip joint. Below the acetabulum, the pubis and ischium surround the obturator foramen.
The pelvic inlet is bounded by the sacral promontory, the arcuate lines and the pubic crests. The female pelvis is usually wider and shallower, with a rounder inlet, a wider subpubic angle and a wider outlet, adaptations for childbirth.
What the 3D model shows
There are two pelvis views on matching male and female bodies. The male pelvis has 3 parts: the left and right hip bones, each as a single bone, and the sacrum. The female pelvis has 8 parts: on each side the ilium, ischium and pubis as separate pieces, plus the sacrum and the coccyx. This makes the female view the one to use for learning the boundaries of the three parts of the hip bone.
How to compare and study the pelvis
Open the male and female views one after the other in the anterior view and compare the subpubic angle and the width of the pelvis. Switch to the superior view to compare the shape of the inlet, more heart-shaped in the male and rounder in the female. In the female view, turn to the lateral view and find the acetabulum, then isolate the ilium, ischium and pubis in turn. Finally, list the main landmarks of each bone from memory and check them on the model.
Views in the 3D model
Male pelvis: the two hip bones and the sacrum.
Open this view in 3DImage: Cogni Anatomy · CC BY 4.0 · Sources: BodyParts3D
Female pelvis with each hip bone split into ilium, ischium and pubis, together with the sacrum and coccyx.
Open this view in 3DImage: Cogni Anatomy · CC BY 4.0 · Sources: HRA
What is in this model
11 3D parts. Names follow the Foundational Model of Anatomy (FMA).
- Bones 11
- Coccyx (female)
- Hip bone
- Ilium
- Ischium
- Pubis
- Sacrum
- Sacrum (female)
Questions
Which bones form the pelvis?
The two hip bones, the sacrum and the coccyx. Each hip bone itself is made of the ilium, ischium and pubis fused together.
What is the difference between the male and female pelvis?
The female pelvis is typically wider and shallower, with a rounder inlet, a wider subpubic angle and a larger outlet. The male pelvis is usually heavier and narrower, with a heart-shaped inlet and a narrow subpubic angle.
What is the difference between the greater and lesser pelvis?
The pelvic brim separates them. The greater pelvis above it, between the iliac wings, is part of the abdominal cavity; the lesser pelvis below it contains the bladder, rectum and internal reproductive organs.
