đź§ 

Fetal Skull Fontanelles Overview

Sep 19, 2025

Overview

The lecture introduces the fetal skull, focusing on the structure and function of the fontanelles—soft spots critical for skull expansion as the brain grows.

Fontanelles of the Fetal Skull

  • Fontanelles are areas of connective tissue in the fetal skull.
  • They allow skull expansion to accommodate the growing brain.
  • Irregular or premature closure of fontanelles can lead to developmental issues.
  • There are four main fontanelles: anterior, posterior, mastoid, and sphenoid.

Locations of Major Fontanelles

  • The anterior fontanelle is located at the front (top) of the fetal skull.
  • The posterior fontanelle is at the back of the fetal skull.
  • The mastoid fontanelle is found on the lateral (side) aspect of the skull.
  • The sphenoid fontanelle is also situated on the lateral side, near the sphenoid bone.

Key Terms & Definitions

  • Fontanelle — a soft spot of connective tissue on a baby's skull that allows for growth and movement of the skull bones.
  • Anterior fontanelle — the largest fontanelle, located at the top/front of the skull.
  • Posterior fontanelle — located at the back of the skull.
  • Mastoid fontanelle — fontanelle found on the side of the skull near the mastoid bone.
  • Sphenoid fontanelle — fontanelle found on the side of the skull near the sphenoid bone.

Action Items / Next Steps

  • Review the locations and names of the four main fontanelles for identification.
  • Prepare for discussion on problems caused by irregular fontanelle closure in future lessons.