Obstetrics and Pelvis Anatomy

Study Notes

Skeletal System

Poor posture, beading of the legs, chest deformity, wasted muscles, poor tone, and difficulty in walking can be signs of skeletal system disorders
Mental confusion, depression, weakness, and sensory deficits can also occur

Pelvis Structure

The pelvis is made up of four bones: sacrum, coccyx, and two innominate bones
The sacrum is formed by the fusion of five sacral vertebrae and is triangular in shape
The sacrum articulates with the coccyx inferiorly and lies between the two innominate bones laterally
The upper border of the 1st sacral bone forms the sacral promontory, which can reduce the diameter of the pelvic brim if prominent
The anterior surface of the sacrum is concave and forms the hollow of the sacrum
Four pairs of foramina are formed where the vertebrae fuse, allowing nerves to pass through and supply the pelvic organs

Sacrum and Coccyx

The sacrum has a sacral canal that runs longitudinally through the center, forming a passage for spinal nerves
The coccyx consists of four fused vertebrae and is triangular in shape, articulating with the sacrum above
The coccyx is of no significance in midwifery

Innominate Bones

The innominate bones are two and lie on either side of the sacrum
Each innominate bone has three parts: ilium, ischium, and pubis
The three parts meet in a cup-shaped depression known as the acetabulum

Ilium, Ischium, and Pubis

The ilium is the large flared-out part of the innominate bone
The upper border of the ilium is known as the iliac crest
The iliac crest terminates anteriorly in the anterior superior iliac spine and posteriorly in the posterior superior iliac spine
The ilium forms the upper two-fifths of the acetabulum
The ischium is the lowest portion of the innominate bone and forms the lower two-fifths of the acetabulum
The ischial tuberosity is the thickened area of bone that forms the body of the ischium
The pubis is the smaller component of the innominate bone and forms the lower one-fifth of the acetabulum

Description

Test your knowledge of the pelvis anatomy, including the structure and composition of the sacrum, innominate bones, and their significance in midwifery. Learn about the different parts of the pelvis and their functions.