Sacrum Anatomy | Sacral Promontory, Cornua, Hiatus, Ala, Apex, Canal

Introduction

In this tutorial, we will explore the anatomy of the sacrum, a triangular bone at the base of the vertebral column. Understanding the sacrum's structure is essential for students in anatomy, nursing, and other health-related fields. We will cover its features, including its landmarks and their functions.

Step 1: Understand the Structure of the Sacrum

• The sacrum is comprised of five individual vertebrae (S1-S5) that fuse together to form a single bone.
• It is classified as an irregular bone and is part of the axial skeleton.
• The sacrum is positioned at the posterior (dorsal) part of the pelvis.

Step 2: Identify the Dorsal Surface Landmarks

Familiarize yourself with the key landmarks found on the dorsal surface of the sacrum:

• Superior Articular Processes: Projections that connect the sacrum to the lumbar vertebrae.
• Sacral Canal: A continuation of the vertebral canal that houses the spinal nerves.
• Dorsal Foramina: Openings for the passage of sacral spinal nerves.
• Sacral Hiatus: An opening at the inferior end of the sacral canal.
• Sacral Cornua: Horn-like projections on either side of the sacral hiatus.
• Median Sacral Crest: A bony ridge formed by fused spinous processes.
• Lateral Sacral Crest: Formed by fused transverse processes.
• Intermediate Sacral Crest: Represents the fused articular processes.

Step 3: Explore the Ventral Surface Landmarks

Examine the important features on the ventral surface of the sacrum:

• Base: The upper part of the sacrum that connects to the lumbar vertebrae.
• Sacral Promontory: The prominent anterior edge of the base, important in obstetrics.
• Ala: The wing-like projections that articulate with the hip bones.
• Lateral Part: The sides of the sacrum that help form the pelvic cavity.
• Apex: The pointed end of the sacrum, which connects to the coccyx.

Step 4: Recognize the Clinical Importance

Understanding sacrum anatomy is crucial for:

• Medical Procedures: Knowledge about landmarks aids in spinal taps and anesthesia administration.
• Assessing Injuries: Recognizing fractures or abnormalities in the sacrum can impact treatment plans.
• Understanding Pelvic Anatomy: The sacrum plays a key role in pelvic stability and function.

Conclusion

In summary, the sacrum is a vital structure in the human body, consisting of several important landmarks that serve various functions. Familiarizing yourself with its anatomy will enhance your understanding of human physiology and aid in clinical practices. Next steps could include taking the sacrum anatomy quiz linked in the video description for further testing of your knowledge.