Pelvis Hip Bones Anatomy (Os Coxae, Pelvic Girdle) - Ilium, Ischium, Pubis

Introduction

This tutorial provides a comprehensive overview of the anatomy of the pelvis, specifically focusing on the hip bones, also known as os coxae or pelvic bones. Understanding the structure of the pelvic girdle is crucial for students in nursing and other health-related fields, as it plays a vital role in protecting pelvic organs and supporting the lower limbs.

Step 1: Identify the Components of the Pelvic Girdle

The pelvic girdle is composed of three fused bones. Familiarize yourself with these components:

• Ilium: The largest part of the hip bone, forming the upper section.
• Ischium: The lower and back part of the hip bone.
• Pubis: The front portion of the hip bone, which connects to the other side at the pubic symphysis.

Step 2: Explore Key Landmarks of the Ilium

The ilium has several important landmarks. Here’s a breakdown:

• Tubercle of Iliac Crest: A small bump on the outer edge of the iliac crest.
• Iliac Crest: The top edge of the ilium, which can be felt on the sides of the pelvis.
• Ala (Wing) of the Ilium: The broad, flat portion of the ilium.
• Anterior Superior Iliac Spine: The prominent bony projection at the front of the iliac crest.
• Posterior Superior Iliac Spine: The corresponding projection at the back of the iliac crest.
• Greater Sciatic Notch: A large notch allowing passage of the sciatic nerve.

Step 3: Understand the Ischium's Structure

Focus on the ischium and its key features:

• Ischial Spine: A pointed projection located on the ischium.
• Lesser Sciatic Notch: A smaller notch located below the ischial spine.
• Ischial Tuberosity: The bony prominence that bears weight when seated.
• Ischial Ramus: The part of the ischium that connects to the pubis.

Step 4: Examine the Pubis and Its Landmarks

The pubis also contains several important structures:

• Body of Pubis: The main central part of the pubis.
• Inferior Ramus of Pubis: The lower branch connecting to the ischium.
• Superior Ramus of Pubis: The upper branch connecting to the ilium.
• Pubic Symphysis: The cartilaginous joint where the two pubic bones meet.
• Pubic Crest and Tubercle: Bony projections on the pubis; the crest runs along the top, and the tubercle is a small bump on the crest.
• Pubic Arch: The angle formed by the inferior rami of the pubis.

Step 5: Learn About the Acetabulum and Other Features

The acetabulum is a crucial part of the pelvis:

• Acetabulum: The socket that receives the head of the femur (thigh bone), forming the hip joint.
• Auricular Surface: The area that articulates with the sacrum.
• Iliac Fossa: The concave surface of the ilium.
• Arcuate Line: A ridge that separates the iliac fossa from the rest of the ilium.
• Obturator Foramen: The large opening in the pelvis created by the ischium and pubis.

Conclusion

Understanding the anatomy of the pelvic girdle is essential for healthcare professionals. This guide provides a structured approach to learning about the hip bones and their landmarks. To deepen your knowledge, consider taking the pelvis anatomy quiz available here. Familiarize yourself with these anatomical structures, as they are critical for both clinical assessments and interventions.