BONES OF THE SKULL Flashcards
FRONTAL BONE
-Cranial bone that forms forehead, superior part of eye orbits & the floor of the anterior cranial fossa
-Eye orbit is the bony sockets that surround the eyeball
-The frontal sinuses are houses within the anterior portion of the frontal bone
PARIETAL BONE
Bilateral bones form the superior (roof) and lateral portions of cranium
parietal means “wall”.
TEMPORAL BONE
-Bilateral bones that help to form the lower side (inferolateral) portions
of the cranium.
-Several markings including that the external auditory meatus (canal), part of the zygomatic process, the styloid process, mastoid process jugular foramen, & the carotid canal
OCCIPITAL BONE
Cranial bone the forms the back (posterior) and most of the base of the skull.
Important structures include the jugular foramen, occipital condyles and the external occipital protuberance
SPHENOID BONE
Cranial bone that is bat-shaped or butterfly shaped bone.
The sphenoid bone articulates with all other cranial bones.
sphen means “wedge shaped”.
Sphenoid sinus is in this bone
Important structures include the Sella Turcica, Optic Foramen, and the carotid canal.
ETHMOID BONE
-Cranial bone that forms part of the anterior cranial fossa, part of the nasal septum and the nasal cavity.
-The ethmoid bone also forms the medial wall of the eye orbit.
-Ethmoid sinus is located within this bone
-Important structures on the ethmoid bone include the crista galli, cribriform foramina, superior and middle nasal conchae
SELLA TURCICA
means “Turkish saddle”
located on the superior surface of the sphenoid bone.
The “seat of the saddle” houses the pituitary gland.
CRISTA GALLI
-Means “rooster’s comb” and is a short finger like projection.
-Projects superior from midline of ethmoid bone
Attaches to the dura mater (outer most layer of the connective tissue surrounding the brain) and helps secure the brain within the skull.
CRIBIFORM PLATE
Plates on either side of the base of crista galli.
Contains olfactory foramina for olfactory nerves to pass through
CAROTID CANAL
Opening through which the internal carotid artery passes into the cranial cavity.
OPTIC FORAMEN/CANALS
Openings at the base of the lesser wings of the sphenoid bone and is anterior to sella turcica.
Optic nerve (cranial nerve II) passes through here.
FORAMEN MAGNUM
-means “large hole”
-Located at the base of the occipital bone allows for the spinal cord to pass through.
JUGULAR FORAMEN
This is a large opening near the foramen magnum and is located on the dense part of the temporal bone.
-The jugular vein and three cranial nerves pass through this opening.
OCCIPITAL CONDYLES
Condyles are rounded surfaces in a joint.
The occipital condyles are bilateral to the foramen magnum.
Articulate with the atlas as in nodding head to indicate “yes”
STYLOID PROCESS
Needle like projection on the temporal bone
Provides attachment for several neck and tongue muscles