Skull Anatomy Study Notes

Skull Anatomy Study Notes

Cranial Bones

• Consists of 8 bones:
  • Frontal Bone: Forms the forehead, contains sinuses.
  • Parietal Bones (2): Forms the superior and lateral aspects of the skull.
  • Temporal Bones (2): Houses structures of the ear, includes the zygomatic process.
  • Occipital Bone: Forms the posterior aspect and base of the skull, contains the foramen magnum.
  • Sphenoid Bone: Bat-shaped, contributes to the base of the skull and orbits.
  • Ethmoid Bone: Forms part of the nasal cavity and orbits, contains the cribriform plate.

Sutures and Foramina

• Sutures: Immovable joints that connect skull bones.

  • Coronal Suture: Between frontal and parietal bones.
  • Sagittal Suture: Between the two parietal bones.
  • Lambdoid Suture: Between parietal and occipital bones.
  • Squamous Suture: Between parietal and temporal bones.

• Foramina: Openings in the skull for nerves and blood vessels.

  • Foramen Magnum: Allows the spinal cord to connect with the brain.
  • Optic Canal: Passage for optic nerve.
  • Jugular Foramen: Pathway for jugular vein and cranial nerves.
  • Foramen Ovale: Passage for mandibular nerve.
  • Foramen Spinosum: Passage for middle meningeal artery.

Facial Bones

• Consists of 14 bones:
  • Maxillae (2): Forms the upper jaw and part of the orbits, contains maxillary sinuses.
  • Zygomatic Bones (2): Cheekbones, contribute to the orbit.
  • Nasal Bones (2): Form the bridge of the nose.
  • Palatine Bones (2): Form the posterior part of the hard palate.
  • Lacrimal Bones (2): Smallest bones in the face, part of the orbit.
  • Inferior Nasal Conchae (2): Curved bones in the nasal cavity.
  • Vomer: Forms part of the nasal septum.

Mandible Structure

• Mandible: The lower jawbone, the largest and strongest facial bone.
  • Body: Horizontal portion that supports the teeth.
  • Rami: Vertical extensions on either side.
  • Condylar Process: Articulates with the temporal bone at the temporomandibular joint (TMJ).
  • Coronoid Process: Site for muscle attachment (temporalis muscle).
  • Mental Foramen: Opening for nerves and blood vessels to the chin.
  • Alveolar Process: Contains sockets for teeth.

Cranial Bones

• Comprises 8 bones providing structural support for the brain.
• Frontal Bone: Forms the forehead and includes frontal sinuses for air exchange.
• Parietal Bones: Paired bones that comprise the upper and sides of the cranium.
• Temporal Bones: Also paired, these bones contain the ear's structures and the zygomatic process, connecting to the cheekbone.
• Occipital Bone: Forms the back and base of the skull, features the foramen magnum, a key opening for the spinal cord.
• Sphenoid Bone: Unique bat-shaped bone contributing to the skull base and eye sockets; aids in cradling the brain.
• Ethmoid Bone: Contributes to the nasal cavity structure and orbits; contains cribriform plate allowing passage of olfactory nerves.

Sutures and Foramina

• Sutures: Immovable joints uniting cranial bones, key for skull integrity.
• Coronal Suture: Connects the frontal bone to the parietal bones.
• Sagittal Suture: Located between the two parietal bones.
• Lambdoid Suture: Junction between parietal and occipital bones.
• Squamous Suture: Links the parietal bone with the temporal bone on each side.
• Foramina: Openings facilitating the passage of nerves and blood vessels.
• Foramen Magnum: Largest foramen that allows spinal cord attachment to the brain.
• Optic Canal: Pathway for the optic nerve connecting the eye to the brain.
• Jugular Foramen: Path for the jugular vein and cranial nerves IX, X, and XI.
• Foramen Ovale: Provides passage for the mandibular branch of the trigeminal nerve.
• Foramen Spinosum: Passage for the middle meningeal artery supplying the meninges.

Facial Bones

• Comprised of 14 bones that form the structure of the face.
• Maxillae: Upper jawbones housing the maxillary sinuses, also part of the orbits.
• Zygomatic Bones: Known as cheekbones, they provide prominence and form part of the eye sockets.
• Nasal Bones: Pair of bones forming the bridge of the nose.
• Palatine Bones: Form the posterior part of the hard palate, contributing to the oral cavity.
• Lacrimal Bones: The smallest facial bones located in the medial wall of each orbit, housing lacrimal sacs.
• Inferior Nasal Conchae: Curved bones within the nasal cavity aiding in airflow regulation.
• Vomer: A singular bone that forms the posterior portion of the nasal septum.

Mandible Structure

• Mandible: The strongest facial bone, pivotal in mastication and facial structure.
• Body: The horizontal segment that holds the lower teeth firmly in place.
• Rami: The two vertical extensions supporting the body on either side.
• Condylar Process: Articulates with the temporal bone at the temporomandibular joint (TMJ), facilitating jaw movement.
• Coronoid Process: Point of attachment for the temporalis muscle, essential for chewing.
• Mental Foramen: Opening allowing the passage of nerves and blood vessels to the chin region.
• Alveolar Process: Contains the sockets for the roots of the lower teeth, ensuring stability.