Pelvic Bone Anatomy Overview

Overview

This lecture covers the anatomy of the coxal (pelvic) bones, focusing on their composite parts, specific surface features, and key anatomical landmarks.

Bones of the Pelvis

• The coxal (hip) bone is formed by fusion of three bones: the ilium, ischium, and pubis.
• The ilium is the uppermost and largest part of the coxal bone.
• The ischium is the lower, posterior part, known as the bone you sit on.
• The pubis is the anterior, front part of the pelvis.

Features of the Ilium

• The iliac crest is the superior (top) curved border of the ilium.
• The greater sciatic notch is a large indentation on the posterior ilium.
• The anterior superior iliac spine is a prominent bump on the front upper ilium.
• The anterior inferior iliac spine is below the anterior superior iliac spine.
• The posterior superior iliac spine is on the back, upper part of the ilium.
• The posterior inferior iliac spine is just below the posterior superior iliac spine.

Features of the Ischium

• The ischial spine is a pointed projection on the ischium.
• The ischial tuberosity is a rough, thick area on the ischium that bears weight when sitting.

Features of the Pubis

• The obturator foramen is a large opening formed by the pubis and ischium.
• The acetabulum is a cup-shaped socket on the pelvis for the head of the femur (thigh bone).

Key Terms & Definitions

• Coxal bone — the hip bone, composed of ilium, ischium, and pubis.
• Ilium — the broad, upper part of the pelvic bone.
• Ischium — the lower back part of the pelvic bone.
• Pubis — the front portion of the pelvic bone.
• Iliac crest — the curved upper border of the ilium.
• Greater sciatic notch — a large notch in the ilium's posterior.
• Anterior/Posterior (Superior/Inferior) Iliac Spine — bony projections on the ilium for muscle attachment.
• Ischial spine — a pointed projection from the ischium.
• Ischial tuberosity — rough area on ischium that supports body weight when sitting.
• Obturator foramen — a large opening in the pelvis.
• Acetabulum — the hip joint socket.

Action Items / Next Steps

• Review the anatomical features of the ilium, ischium, and pubis.
• Practice identifying these structures on bone models or diagrams.