Skull anatomy
Mandible
body: forms the chin ramus: vertical extension of the body mandibular condyle: articulation point with the mandibular fossa coronoid process: projection anterior to the mandibular condyle mandibular angle: where the body and ramus meet mental foramen: prominent opening on the body alveoli/alveolar process: sockets for lower teeth mandibular symphysis: anterior depression of the chin
Temporal bones
styloid process: needle-like projection zygomatic process: bridge-like structure joining temporal & zygomatic (cheek) bones mastoid process: rounded projection posterior to the ear mandibular fossa: rounded projection forming a socket for the jaw bone (mandible) external auditory meatus: "ear" canal
Floating Ribs
# 11 and 12 are free floating, DO NOT attach to Sternum
What is a Process?
A site for muscle attachment:
Lacrimal Fossa
Anterior and lateral depression of roof of orbit which accommodates the lacrimal gland
Sphenoid
Base and sides of skull; part of the eye orbits.
Occipital Bone Landmarks and Openings
Basilar portion of occipital External occipital crest External occipital protuberance (inion) Internal occipital protuberance Occipital condyles Jugular foramen (between occipital and petrous part of temporal) Foramen magnum Hypoglossal canal Clivus (finger slot above foramen magnum) Groove for sinuses Cerebellar fossa (smooth spaces for cerebellar hemispheres to sit) Superior nuchal line Inferior nuchal line
Mandible Bone Landmarks and Openings
Body (horizontal portion) Ramus (vertical portion) Angle of mandible Coronoid process (anterior process) Mental tubercle/protuberance Mental foramen
Jugular Foramen
CN IX, X, XI, superior bulb of internal jugular, inferior petrosal and sigmoid sunuses, meningeal branches of ascending pharyngeal and occipital arteries pass through
Occipital bones
Cranial foramen magnum: large opening at the base of the skull where the spinal cord joins the brain occipital condyles: rounded projections which articulate the atlas external occipital protuberance: large "bump" on the posterior surface (bump at the back of the head)
Sphenoid Bone
Cranial greater wings: form parts of the middle cranial fossa and external wall of the skull lesser wings: form part of the floor of the middle cranial fossa sella turcica: houses and protects the pituitary gland
Ethmoid
Cranial Next to nose crista galli: thin projection that anchors the dura mater to the skull cribriform plates: flat plates on either side of the crista galli
Glabella
Cranial ***
Cranial Fossae
Cranial fossae are shallow depression in the cranial floor where the brain rests.
Sutures
Cranial sutures are interlocking joints where the cranial bones meet. The suture lines have a serrated (saw-toothed) appearance that can easily be viewed on the external surface of the skull.
Palatine
Either of two irregularly shaped bones that form the back of the hard palate and helps to form the nasal cavity and the floor of the orbits
Maxillae
Facial bone alveoli/alveolar process: sockets for upper teeth infraorbital foramen: small opening under the orbit
What are the foramens found in the sphenoid bone?
Foramen rotundem Foramen ovale, Foramen lacerum Foramen spinosum
Maxilla
Forms most of the upper jaw, and part of the hard palate, contains upper molars, premolars, and canines
Frontal Bone Landmarks and Openings
Glabella (forehead between eyes) Nasion (between nasal and frontal bones) Supraorbital margin Frontal crest Supraorbital foramen (notch) Orbit roof (internal view)
Sphenoid Bone Landmarks and Openings
Greater wing Superior orbital fissure Lesser wing Inferior orbital fissure Foramen rotundum Foramen ovale Foramen spinosum Foramen lacerum Optic canal Pterygoid fossa—smooth spot between lateral/medial plates Sella turcica Anterior clinoid process Posterior clinoid process (horns)
Ethmoid
Internal base of skull; structures in nasal cavity.
Hyoid Bone
Is a bone in the body that does not articulate with any other bone. Its various landmarks (body and cornus (horns)) serve as attachment points for various muscles of the neck.
Sagital Suture
Located on the midline of the skull lies between both parietal bones (immovable joint)
Significance of a Foramen?
Location where Blood vessels and nerves have a passageway through bone
Cribiform plate
Location: • Ethmoid bone Description: • Bony plate with foramina (holes) that transmit olfactory nerves (CN I) Comment: • Contributes to anterior midline portion of anterior cranial fossa
Seperate Bone Landmarks and Openings
Nasal Bone (and septum) Vomer Bone Lacrimal Bone Inferior Nasal Concha Palatine Bone (posterior 1/3 of roof of mouth)
Optic Foramen
On either side ochiasmatic groove -transmits optic nerve (CN II) along with its meningeal coverings, and the ophthalmic artery
Frontal
Part of the cranial bones supraorbital foramen: small opening above each orbit supraorbital margin: superior ridge of each orbit (eyebrow) glabella: smooth surface between the orbits (between eyebrows)
Temporal Bone Landmarks and Openings
Squamous portion Petrous portion Internal auditory meatus External auditory meatus Carotid canal (inferior view) Stylomastoid foramen (inferior view) Styloid process Mastoid process Digastric notch (posterior to mastoid process) Zygomatic process of temporal bone Groove for middle meningeal artery ("Y" shaped)
Ethmoid Bone Landmarks and Openings
Superior nasal concha Crista galli Middle nasal concha Cribriform plate Perpendicular plate Paranasal sinus
Parietal Bone Landmarks and Openings
Superior temporal line Inferior temporal line
Alveolar Process
a ridge that forms the borders of the upper and lower jaws and contains the sockets of the teeth
Occipital Bone
a saucer-shaped membrane bone that forms the back of the skull
Openings in the Skull
allow nerves and blood vessels to pass through the skull.
Nasal Bone
an elongated rectangular bone that forms the bridge of the nose
Squamosal Suture
between parietal bone and temporal bone on side of the skull, bordered in back by occipital bone
Aveolar Process
bone surronding the teeth
Temporal Bone
bone that forms parts of the side of the skull and floor of the cranial activity. There is a right and left temporal bone.
Hyoid Bone
bone that is suspended in the mid neck region and provides a moveable base for the tongue
Sella turcica
depression in the sphenoid bone where the pituitary gland is located
Madibular fossa
depressions where manidble and cranium meet and join
Coronal
divides parietal and frontal bones
Lamboid
divides parietal and occipital bones
Squamosal
divides parietal and temporal bones
Sagittal
divides parietal bones
Palatine Bone
either of two irregularly shaped bones that form the back of the hard palate and helps to form the nasal cavity and the floor of the orbits
Parietal Bone
either of two skull bones between the frontal and occipital bones and forming the top and sides of the cranium
Palatine Process
forms the anterior portion of the hard palate (roof) of the mouth also forms parts of the nasal cavity and eye orbits
Anterior cranial fossa
holds the frontal lobes of the brain
External Auditory Meatus
hole in the temporal bone extending medially to the inner ear
Palatine
lie underneath the maxillae and form the floor of the nasal cavity
Inferior nasal Concha
located on each side of the nasal septum, attached to the lateral wall of the nasal cavity; increase epithelial surface area and create turbulence in the inspired air
Downward Facing Openings
o Foramen ovale—CN V3 (sphenoid) o Foramen spinosum—middle meningeal artery (sphenoid) o Olfactory foramen—Olfactory nerve (CN I) (ethmoid, Cribiform plate) o Foramen lacerum—Internal carotid artery (sphenoid) o Jugular foramen—CN IX, X, and XI (temporal) Internal jugular vein o Carotid canal (temporal) internal carotid artery
Lateral Facing Openings
o Internal auditory meatus— CN VII and VIII (temporal) o Hypoglossal canal—CN XII (occipital)
Forward Facing Openings
o Optic canal—optic nerve (CN II) (sphenoid) o Superior orbital fissure—(CNIII, IV, V1, and VI) (sphenoid) o Foramen rotundum—CN V2 (sphenoid)
Maxillary Bone Landmarks and Openings
o Palatine process of maxilla bone (anterior 2/3 of roof of mouth) o Incisive foramen (hole on roof of mouth behind front teeth) o Intermaxillary suture o Infraorbital foramen o Alveolar process (tooth bumps)
Zygomatic Bone Landmarks and Openings
o Zygomatic arch
Carotid Foramen
opening for carotid artery
Mastoid Process
projection of the temporal bone located behind the ear
Occipital Condyle
ridges on left and right of foramen magnum
Lacrimal Bone
small fragile bone making up part of the front inner walls of each eye socket and providing room for the passage of the lacrimal ducts
Styloid Process
spike-like process extending downward from the temporal bone on each side of the skull
Cribiform plate
superior surface of the ethmoid; perforated by a foramina which allows passage of the olfactory nerves, which provide sense of smell
Posterior cranial fossa
supports the cerebellum
Middle cranial fossa
supports the temporal lobes of the brain
Lambdoidal Suture
suture that separates parietal bones from occipital bone
Zygomatic Bone
the arch of bone beneath the eye that forms the prominence of the cheek
Condylar Process
the condyle of the ramus of the mandible that articulates with the skull
Temporomandibular joint (TMJ)
the joint between the head of the lower jawbone and the temporal bone
Frontal Bone
the large cranial bone forming the front part of the cranium: the forehead and the upper part of the orbits
Foramen Magnum
the large opening at the base of the cranium through which the spinal cord passes
Mandible
the lower jawbone in vertebrates
Middle nasal Concha
the middle thin, spongy, bony plate with curved margins, part of the ethmoidal labyrinth, projecting from the lateral wall of the nasal cavity and separating the superior meatus from the middle meatus;
Coronal Suture
the suture between the parietal and frontal bones of the skull
Vomer
thin trapezoidal bone of the skull forming the posterior and inferior parts of the nasal septum (the lower portion of the nasal septum)
Crista Galli
vertical projection providing a point of attachment for the dura mater, helping to secure the brain within the skull
Inferior Nasal Conchae
very thin, curved bones within the nasal cavity
Junctions
• Bregma • Lambda
