Skull Bones Study Guide

Skull Bones Study Guide

Overview

This study guide covers various bones and features of the human skull, categorized by major bone types and sutures that connect them.

Major Bones of the Skull

Frontal Bone

  • Definition: The frontal bone forms the forehead and the upper part of the eye sockets (orbits).

  • Feature: Coronal Suture

    • Description: The suture that connects the frontal bone to the parietal bones.

Parietal Bone

  • Definition: The two parietal bones form the sides and roof of the cranium.

  • Feature: Sagittal Suture

    • Description: The suture that connects the two parietal bones along the midline of the skull.

Temporal Bone

  • Definition: The temporal bones are located on the sides of the skull and house structures of the ear.

  • Features:

    • Squamous Suture: Connects the temporal bone to the parietal bone.

    • Mastoid Process: A bony projection located behind the ear, serves as an attachment for muscles.

    • External Auditory Meatus: The ear canal which leads to the eardrum.

    • Mandibular Fossa: A depression where the mandible articulates with the skull.

    • Zygomatic Arch: Formed by the temporal bone and the zygomatic bone, it can be felt as the cheekbone.

Occipital Bone

  • Definition: The occipital bone is located at the back and base of the skull; it houses the foramen magnum, the large opening for the spinal cord.

  • Feature: Lambdoid Suture

    • Description: The suture that connects the occipital bone to the parietal bones.

Sphenoid Bone

  • Definition: A complex bone located at the base of the skull, it is often referred to as the keystone of the cranial floor because it articulates with all other cranial bones.

Ethmoid Bone

  • Definition: A light, spongy bone located between the eyes; it forms part of the nasal cavity and the orbits.

Facial Bones
Maxilla

  • Definition: The maxilla is the upper jawbone that also forms part of the orbits and nasal cavity.

Nasal Bone

  • Definition: The two small bones that form the bridge of the nose.

Lacrimal Bone

  • Definition: The smallest bones of the face, located in the medial wall of each orbit, they contain the lacrimal sac which is involved in tear drainage.

Zygomatic Bone

  • Definition: Known as the cheekbone, it forms the prominence of the cheeks and part of the orbit.

Vomer

  • Definition: A thin, flat bone forming part of the nasal septum, separating the left and right air passages.

Palatine Bone

  • Definition: The palatine bones form part of the hard palate of the mouth and the floor of the nose.

Mandible

  • Definition: The lower jawbone, the largest and strongest bone of the face.

  • Features:

    • Body of Mandible: The horizontal part of the mandible which holds the lower teeth.

    • Ramus of Mandible: The vertical part that connects to the skull and supports the jaw joint.

    • Mental Foramen: An opening in the body of the mandible that allows nerves and blood vessels to enter the chin area.