University of Mount Saint Vincent

Introduction to the Skull Anatomy

  • Study Techniques

    • Use colored skull models to identify bone structures.

    • Use neutral-colored skulls to reinforce learning by comparison.

    • Suggested method: Use tape to label bones for hands-on learning.

    • Use online resources like Visible Body for interactive study.

Sutures of the Skull

  • Types of Sutures

    • Coronal Suture: Connects frontal bone to parietal bones.

    • Squamous Suture: Connects temporal bone to parietal bones.

    • Lambdoid Suture: Connects occipital bone to parietal bones.

    • Sagittal Suture: Splits the left and right parietal bones.

  • Importance of Borders

    • Need to understand which bones sutures connect.

Temporal Bone Anatomy

  • Distinct Parts of Temporal Bone

    • Mastoid Process: Bump behind the ear, identifiable by "p".

    • Styloid Process: Spike pointing downward, identifiable by "t".

    • External Acoustic Meatus: Opening, tube-like structure.

    • Mandibular Fossa: The dent where the mandible articulates.

Inside the Skull

  • Overview of Internal Structures

    • Viewing inside the skull: transverse plane, posterior to midline orientation.

    • Foramen Magnum: Large hole in the occipital bone allowing the passage of the brainstem and spinal cord.

    • Sphenoid Bone: Shaped like a bat wing, contains the Sella Turcica (holds pituitary gland).

Important Cranial Structures

  • Crista Galli and Cribriform Plate

    • Both parts of the ethmoid bone.

    • Crista Galli: Ridge in the ethmoid bone.

    • Cribriform Plate: Sponge-like structure with holes for olfactory nerves.

    • Functionality: Sense of smell; injury to the cribriform plate can lead to loss of smell.

Sinuses of the Skull

  • Definition and Function

    • Sinuses: Hollow portions filled with air to lighten the skull and influence voice resonance.

    • Four Major Sinuses:

      • Frontal Sinus: Superiorly located, causes pain when inflamed.

      • Ethmoid Sinus: Located behind the nose.

      • Sphenoid Sinus: Posterior, behind the eyes.

      • Maxillary Sinus: Under the nose and near upper teeth.

Special Bone Structures

  • Hyoid Bone: Unique bone not articulating with others, supportive to the tongue and larynx.

  • Fetal Skull Development

    • Comprises about 25% of body length at birth.

    • No sutures—features fontanelles (fibrous membranes connecting cranial bones).

    • Important for birth and brain growth; closes around age 2 to form sutures.

Vertebral Column Overview

  • Regions of Vertebrae

    • Cervical: 7 vertebrae (C1-C7).

    • Thoracic: 12 vertebrae (T1-T12).

    • Lumbar: 5 vertebrae (L1-L5).

    • Sacral: 5 fused bones into the sacrum.

    • Coccyx: Tailbone, may vary in number of fused vertebrae.

  • Importance of Spine Curves

    • Primary curve at birth (single C shape).

    • Secondary curves develop in cervical and lumbar regions with crawling and mobility.

Spine Curvature Types

  • Scoliosis: Abnormal lateral curve.

  • Kyphosis: Excessive anterior curve, which can develop from poor posture or aging (compression fractures common).

  • Lordosis: Normal inward curve; hyperlordosis refers to excessive curvature typically caused by abdominal obesity, pregnancy, or athletic muscle development.

Conclusion

  • Importance of understanding proper skeletal anatomy for physiological health.

  • Acknowledge potential implications and complications from abnormal spine or skull anatomy.

  • Reminder for upcoming quiz covering skin anatomy and sensory pathways.