Skull Osteology

Week 2

Frontal description

Forms forehead and part of each orbit

Frontal function

Protects frontal lobe, forms a portion of the orbital complex

Supraorbital Foramen (ext) description

Hole above eye sockets

Supraorbital Foramen (ext) function

Passage for veins/arteries and CN V₁

Occipital description

Forms back/base of skull

Occipital function

Protects cerebellum and occipital lobe

Foramen Magnum (ext/int) description

Large opening in occipital bone

Foramen Magnum (ext/int) function

Spinal cord and CN XI passage

Hypoglossal Canal (int) description

Holes that look like they are inside of the Foramen magnum

Hypoglossal Canal (int) function

CN XII passage

Occipital Condyle (ext) description

Big bone bulges lateral to the Foramen magnum (inferior view only)

Occipital Condyle (ext) function

Articulates with the C1 vertebrae called the Atlas

Nuchal Line (superior and inferior)(ext) description

Line on occipital

Nuchal Line (superior and inferior)(ext) function

Muscle attachment

Parietal description

Posterior to frontal bone and on either side of midline

Parietal function

Protects parietal lobe

Temporal description

Anterior to occipital and inferior to parietal

Temporal function

Protects temporal lobe

Jugular foramen (int) description

Opening between occipital and temporal bone

Jugular foramen (int) function

Cranial nerve passage for CN IX, X, XI, and Jugular vein

External Acoustic Meatus (ext) description

Ear hole connecting to the internal acoustic meatus

External Acoustic Meatus (ext) function

Opening for initial sound waves to travel through before reaching the processing centers in the inner ear

Internal Acoustic Meatus (int) description

Tunnel in temporal bone

Internal Acoustic Meatus (int) function

Cranial nerve passage for CN VII and VIII

Carotid Canal (ext) description

Canal in temporal bone

Carotid Canal (ext) function

Vessel passage

Stylomastoid Foramen (ext) description

Hole between mastoid and styloid processes

Stylomastoid Foramen (ext) function

CN VII exits here

Styloid process (ext) description

Slender projection protruding from inferior of temporal bone

Styloid process (ext) function

Attachment site for hyoid ligaments and other neck muscles

Mastoid Process (ext) description

Projects inferiorly from temporal bone

Mastoid Process (ext) function

Attachment of diagastric and sternocleidomastoid muscles

Mandibular Fossa (ext) description

Bole like feature directly posterior to the zygomatic arch on the inferior view of the skull

Mandibular Fossa (ext) function

Articulates with the mandible, where people can get Temporomandibular joint issues

Zygomatic Arch (ext) description

Arch formed from zygomatic and temporal bones

Zygomatic Arch (ext) function

Attachment of masseter muscle

Zygomatic description

Forms prominences of cheeks and part of each orbit

Zygomatic funciton

Articulates with the frontal, sphenoid, temporal, and maxilla bones, forms portion of the orbital complex

Maxilla description

Forms upper jaw, part of hard palate, part of each orbit

Maxilla function

Helps form portion of orbital complex and roof of oral cavity

Infraorbital Foramen (ext) description

Inferior to each orbit

Infraorbital Foramen (ext) function

Passageway for blood vessels and CN V₂

Incisive Foramen description

Singular hole in the anterior portion of the maxilla (roof of mouth behind the big front teeth)

Incisive Foramen function

Passage for nasopalatine nerve

Palatine Process of Maxilla (ext) description

Forms hard palate

Palatine Process of Maxilla (ext) function

Floor of nasal cavity and roof of mouth

Mandible description

Forms lower jaw

Mandible function

Holds teeth, allows mastication, and articulates with temporal bone to form joint

Alveolar Processes (ext) (on both Mandible and Maxilla) description

Oral margins of the maxilla and mandible

Alveolar Processes (ext) (on both Mandible and Maxilla) function

Contain tooth roots and alveolar nerves

Mental Protuberance (ext) description

Bottom of chin

Mental Protuberance (ext) function

Forms the chin

Mental Foramen (ext) description

Opening in mandible lateral to chin

Mental Foramen (ext) funciton

Vessel and nerve passage, CN V₃

Mandibular Body (ext) description

Horizontal, curved portion

Mandibular Body (ext) function

Forms lower jaw

Mandibular Ramus (ext) description

Vertical portion of mandible

Mandibular Ramus (ext) function

Condyles articulate with temporal bone (allows movement in jaw)

Coronoid Process (ext) description

Projection on mandible that is anterior to condylar process

Coronoid Process (ext) function

Attachment of temporalis muscle

Condylar Process (ext) description

Rounded projection on mandible

Condylar Process (ext) function

Articulates with mandibular fossa

Mandibular Head (ext) description

Located on Condylar process

Mandibular Head (ext) function

Provides surface for articulation

Mandibular Foramen (int) description

Located on the inner surface of the mandibular ramus

Mandibular Foramen (int) function

Passage of CN V₃

Nasal description

Forms bridge of nose

Nasal function

Be able to identify

Lacrimal description

Next to the zygomatic portion/nasal portion of the orbit, where the lacrimal gland sits (produces tears)

Lacrimal function

Forms part of the medial portion of the orbital complex

Palatine description

Forms part of hard palate

Palatine function

It contributes to floor of nasal cavity, roof of mouth, adn a small portion of the orbital complex

Greater Palatine Foramen (ext) description

Paired holes in hard palate (back towards molars on the roof of the mouth)

Greater Palatine Foramen (ext) function

Passage for nerves/vessels, CN V₂

Vomer (ext) description

Forms part of nasal septum

Vomer (ext) function

Be able to identify

Sphenoid description

Posterior to face, extends from one temple ot the other, forms part of orbit

Sphenoid function

Articulates with frontal, parietal, and temporal bones, part of the orbital complex

Superior Orbital Fissure (ext) description

Top part of the C shape in the eye socket

Superior Orbital Fissure (ext) function

Passageway for CN III, CN IV, CN V₁, CN VI

Inferior Orbital Fissure (ext) description

Separates the lower wall and floor of orbit (lower part of C shape in eye socket)

Inferior Orbital Fissure (ext) function

Passageway for CN V₂

Optic Canal (ext/int) description

Round pening in sphenoid bone in posterior part of orbit

Optic Canal (ext/int) function

Cranial nerve passage CN II

Greater wings of the Sphenoid (int/ext) description

A process of the sphenoid bone, mainly located behind the eyes in the middle of the cranial vault, Foramen Rotundum, Ovale, and Spinosum can be found on this portion of the sphenoid

Greater wings of the Sphenoid (int/ext) function

Aids in forming the base and a little of the sides of the skull, aids in forming the inferior and lower lateral portion of the eye socket

Lesser wings of the Sphenoid (int/ext) description

A triangular shaped region of the sphenoid located superiorly to the greater wings of the sphenoid, the optic canal the superior orbital fissure can be found in this region

Lesser wings of the Sphenoid (int/ext) function

Supports portions of the frontal lobe and forms the posterior, superior aspect of the eye socket, and helps form the superior orbital fissure

Foramen Lacerum (in association with Temporal and Occipital bones, the marking belongs to the Sphenoid, but it lies smack between all three bones) (ext/int) description

Most medial foramen is seemingly composed of the Sphenoid, Temporal, and Occipital bone, slightly posterior and lateral to the vomer

Foramen Lacerum (in association with Temporal and Occipital bones, the marking belongs to the Sphenoid, but it lies smack between all three bones) (ext/int) funciton

Nerve/artery/vein passageway for function

Foramen Rotundum (int) description

Located on the greater wing of the sphenoid, this opening. is inferior to the superior orbital fissure, and both superior and medial to foramen ovale, often almost a perfect circule in shape

Foramen Rotundum (int) function

Passage for Cn V₂ to exit skull

Foramen Ovale (ext/int) description

Oval opening in the greater wing of the sphenoid bone, inferior to foramen Foramen Rotundum but superior to the Foramen Spinosum, lateral to the Sella Turcica

Foramen Ovale (ext/int) function

Passageway for Cn V₃ to exit skull

Foramen Spinosum (ext/int) description

Smallest foramen, almost shaped like a perfect circle, located inferior to foramen ovale, lateral to Sella Turcica

Foramen Spinosum (ext/int) function

Nerves and vessels pass through here

Sella Turcica (int) description

Depression in sphenoid bone, saddle shaped

Sella Turcica (int) function

Location of pituitary gland

Dorsum Sellae (int) description

A bony ridge which forms posterior wall of Sella Turcica

Dorsum Sellae (int) function

Location of pituitary gland