Overview
This lecture reviews the key external bones, sutures, and notable foramina (holes) and processes on the human skull, highlighting their locations and anatomical names.
Sutures of the Skull
- Sutures are immovable joints between skull bones, visible as "cracks."
- Coronal suture separates the frontal bone from the parietal bones.
- Sagittal suture divides the two parietal bones.
- Squamous suture separates the parietal bone from the temporal bone.
- Lambdoid suture separates the occipital bone from the parietal bones.
Major Skull Bones and Key Features
- Frontal bone (forehead); glabella is the area between the eyebrow ridges.
- Supraorbital foramen: holes above each eye orbit in the frontal bone.
- Parietal bones: paired, separated from each other by the sagittal suture.
- Temporal bone: houses zygomatic process, mandibular fossa, and external auditory meatus (ear canal).
- Styloid process: pointed projection from the temporal bone.
- Mastoid process: rounded projection from the temporal bone.
- Stylomastoid foramen: hole between styloid and mastoid processes.
- Jugular foramen: large hole for jugular vein.
- Carotid canal: passage for carotid artery.
- Sphenoid bone: contains foramen ovale, foramen spinosum, foramen lacerum, and optic canal.
- Superior and inferior orbital fissures: large cracks in the eye orbit.
- Occipital bone (back/lower skull): foramen magnum (large hole for spinal cord), occipital condyles (articulate with first vertebra), and hypoglossal canal.
- Superior and inferior nuchal lines: ridges on occipital bone.
- Ethmoid bone: visible features include perpendicular plate and middle nasal conchae.
- Mandible (lower jaw): includes body, ramus, mandibular condyle, coronoid process, mandibular notch, angle, mental foramen (chin), and mandibular foramen (inside).
- Maxilla (upper jaw): forms upper lip, contains infraorbital foramen, palatine process and incisive fossa.
- Palatine bone: forms part of hard palate in mouth.
- Zygomatic bone: cheekbone.
- Lacrimal bone: small bone near inner eye, contains lacrimal fossa.
- Nasal bones: make up the bridge of the nose.
- Vomer: forms part of the nasal septum.
- Inferior nasal conchae: low nasal cavity bones.
Key Terms & Definitions
- Suture — an immovable joint between skull bones.
- Foramen — a hole or opening in bone for nerves/vessels.
- Fossa — a depression or hollow in a bone.
- Process — a projection or outgrowth of bone.
- Condyle — a rounded articular area on a bone.
- Canal — a tunnel-like passage through a bone.
- Concha — a curved bone in the nasal cavity.
Action Items / Next Steps
- Review labeled diagrams of the skull for visual reinforcement.
- Memorize bone names, sutures, and key foramina for identification.
- Study the definitions of anatomical terms listed above.