skull

Skull Anatomy Overview

General Structure

  • Composed of 22 bones.

    • Mandible: lower jaw.

    • Sutures: fibrous joints that connect skull bones.

Fetal Skull

  • Structure consists of:

    • 2 Frontal bones.

    • 2 Parietal bones.

    • 2 Temporal bones.

    • 1 Occipital bone.

  • Fontanelle: Irregular spaces formed where sutures meet, covered by a membrane.

Calvaria and Facial Skeleton

Calvaria

  • Refers to the upper domed part of the skull.

  • Composed of:

    • Frontal Bone

    • Parietal Bones

    • Occipital Bone

    • Temporal Bones

    • Sphenoid Bone

Facial Skeleton

  • The facial skeleton includes:

    • Maxilla

    • Nasal

    • Lacrimal

    • Zygomatic (cheekbone)

    • Palatine

    • Vomer

    • Incisive

Anterior Skull Features

Anterior View Components

  • Frontal Bone: Contains features such as:

    • Superciliary Arch

    • Glabella

    • Nasion: Intersection of frontal and nasal bones.

    • Piriform Aperture: The large opening for the nasal cavity.

    • Inferior Nasal Concha

    • Zygomatic Process

    • Maxilla and its features:

      • Ramus of Mandible

      • Angle of Mandible

  • Foramina:

    • Supra-orbital notch (contains vessels and nerves).

    • Infra-orbital foramen (for vessels and nerves).

Cranial Sutures and Their Locations

Key Sutures

  • Coronal Suture: Connects frontal and parietal bones.

  • Lambdoid Suture: Connects parietal and occipital bones.

  • Pterion: Junction of parietal, temporal, and sphenoid bones.

Cranial Floor Anatomy

Anterior Cranial Fossa

  • Contains:

    • Foramen Cecum: For emissary veins to the nasal cavity.

    • Cribriform Plate: Houses olfactory nerves (CN I).

    • Optic Canal: For optic nerve and ophthalmic artery.

    • Crista Galli: Attachment point for the falx cerebri.

Middle Cranial Fossa

  • Contains:

    • Hypophysial Fossa: Holds the pituitary gland.

    • Major foramina serving various cranial nerves and vessels:

      • Superior Orbital Fissure: Carries oculomotor (CN III), trochlear (CN IV), and abducens nerves (CN VI), as well as branches of the trigeminal nerve.

Posterior Cranial Fossa

  • Contains structures and foramina for:

    • Jugular Foramen: For glossopharyngeal (CN IX), vagus (CN X), and accessory nerve (CN XI).

    • Hypoglossal Canal: For hypoglossal nerve (CN XII).

    • Foramen Magnum: Allows passage for vertebral arteries and meninges.

Skull Base Anatomy

  • Extends from:

    • Anteriorly from the middle incisors to the posterior superior nuchal lines.

    • Laterally to mastoid processes and zygomatic arches.

Skull Fractures

  • Skull fractures can occur due to trauma and require medical attention.

Note: The details provided are for study purposes based on the presentation by Ms P Pillay in 2013.