cranial bones cm1 Flashcards
skull division
neurocranium, viscerocranium, associated bones
Neurocranium second name
calvaria basicranium
viscerocranium second name
splanchnocranium
what are associated bones?
6 auditory ossicles and hyoid bone
what does the neurocranium harbors
brain, meninges, proximal parts of the cranial nerves, and blood vessels
Where are the auditory ossicles located?
temporal bone
what is the craniometric reference known as
orbitomeatal or Frankfurt plane
what lies in the plane of the orbitomeatal
the inferior part of the orbit, the superior part of the external acoustic meatus, and the lateral canthus
characteristics of the neurocranium bones
-flat
-curved
-joined by fibrous interlocking joins
-thickness varies by region, age, and gender
-inner and outer plates are separated by spongy bone that contains red bone marrow
the 2 halves of the frontal bone are separated by the frontal suture until….
6 years of age
info about the frontal bone (4)
-forms the upper margin of the orbit
-squamous part forms the forehead
-fetal skull has 2 frontal bones until they fuse (some adults persists as a metopic suture in the middle of the glabella)
-nasion intersection of the frontal and nasal bones
what does the supraorbital margin consist of?
the supraorbital arch and notch
what is the supraorbital margin?
angular body between the squamous and the orbital part of the frontal bone.
what is the purpose of the supraorbital foramen?
a passageway for the supraorbital nerves and vessels.
superciliary arch
-found superiorly of the supraorbital margin
-extends laterally from the glabella
-found more in males
frontal sinuses and functions
-2 hollow spaces just above the orbital margins
-lightens the skull
-act as a voice resonator
lacrimal fossa
a depression in the inferior surface of the orbital plate of the frontal bone, which provides a shallow depression for the lacrimal gland.
articulations of the frontal bone (7)
-parietal bone
-sphenoid bone
-ethmoid bone
-lacrimal bone
-nasal bone
-zygomatic bone
-maxillary bone
info about the parietal bone
-superior and lateral part of the cranium
-slightly curved, has a quadrilateral shape
- 2 surfaces, 4 borders, 4 angles
articulations of the parietal bone (5)
-other parietal bone
-frontal bone
-sphenoid bone
-temporal bone
-occipital bone
borders of the parietal bone
-sagittal border
-squamosal border
-frontal border
-occipital border
sagittal border of the parietal bone?
articulation of 2 parietal bones
squamosal border of the parietal bone?
1- greater wing of the sphenoid (sphenoparietal suture)
2- squamous part of the temporal bone forming the (squamous suture)
3- mastoid part of the temporal bone (parietomastoid suture)
4- petrous part of the temporal bone
frontal border of the parietal bone?
connects to the frontal bone to form the coronal suture
occipital border of the parietal bone?
connects to the occipital bone to form the lambdoid suture
superior parietal line?
origin of the CT that surrounds the temporalis muscle
inferior parietal line?
attachment site for the temporalis muscle
interior markings of the parietal bone?
surface grooves for blood vessels
info on the temporal bone?
-contains hearing and balance organs
-surrounds and protects the inner ear
-provides attachment site for head and jaw muscle
articulations of the temporal bone (5)
-occipital bone
-parietal bone
-sphenoid bone
-zygomatic bone
-mandible bone
parts of the temporal bone
-squamous
-tympanic
-mastoid
-petrous
squamous part of the temporal bone?
borders the squamous suture
tympanic part of the temporal bone?
forms parts of the anterior and posterior wall of the external acoustic meatus.
mastoid part of the temporal bone?
gives muscle attachments
petrous part of the temporal bone?
encloses structures of the inner ear
What is the pointed projection in the temporal bone?
styloid process
temporal bone process
-mastoid process
-styloid process
-zygomatic process
mastoid process of the temporal bone?
-muscle attachment
-mastoid air cells connected to the middle ear
styloid process of the temporal bone?
attach tendons and ligaments of the tongue, pharynx, and hyoid
zygomatic process of the temporal bone?
articulates with the temporal process of the zygomatic
bone to form the zygomatic arch
auditory ossicles?
3 tiny bones in the tympanic cavity, transfer sound form the tympanic membrane to the inner ear
auditory ossicles names
largest: malleus
middle: incus
smallest: stapes
What does the carotid canal allow
Allows the internal carotid artery to pass
Two names for auditory tube?
Eustachian tube and pharyngo-tympanic tube
Eustachian tube function?
connects the middle ear to the wall of the nasopharynx.
facial nerves, vestibulocochlear nerve, and labyrinthine artery.
stylomastoid foramen of the temporal bone
for facial nerves
Foramen lacerum of the temporal bone
the greater petrosal nerve passes through it
occipital bone function
formes the posterior and inferior part of the cranium.
articulations of the occipital bone
parietal bone
temporal bone
sphenoid bone
first cervical vertebra (atlas)
occipital bone parts
basilar part
condylar part
squamous part
occipital bone landmarks
-external occipital protuberance
-external occipital crest
-superior and inferior nuchal lines
-occipital condyles
external occipital protuberance
attaches trapezius muscle
external occipital crest
provide attachments for nuchal ligaments
superior and inferior nuchal lines
attachment site of muscles and ligaments
occipital condyles
articulates with the neck
foramen of the occipital bone
-foramen magnum
-jugular foramen
-hypoglossal canal
foramen magnum?
connects the cranial and spinal cavities
jugular foramen?
for jugular veins
hypoglossal canal?
for hypoglossal nerves
sphenoid bone functions and info
-part of the floor of the cranium
-unites cranium and facial bones
-strengthens sides of the skull
-contains sphenoidal sinuses
-body has greater wings, lesser wings, and 2 pterygoid processes
articulations of the sphenoid bone
-all cranial bones
-zygomatic bone
-maxillary bone
-palatine bone
-vomer
marks of the sphenoid
-sphenoid body
-sella turcica
-hypophyseal fossa
-sphenoidal sinuses
-greater wing
-lesser wing
-pterygoid processes
sphenoid body?
-found at the central axis of the sphenoid
sella turcica?
saddle-shaped enclosure
-on the superior surface of the body
hypophyseal fossa?
-a depression in the sella turcica
-holds the pituitary gland
greater wing?
part of the cranium floor
posterior part of the orbit
pterygoid processes?
forms pterygoid plates.
allows muscle attachment of the lower jaw and soft palate
foramen of the sphenoid bone
-optic canals
-superior orbit fissures
-foramen rotundum
-foramen ovale
-foramen spinosum
optic canals?
for optic nerves
superior orbit fissures?
for blood vessels and nerves of the orbit
foramen rotundum?
for blood vessels and nerves of the face
foramen ovale?
for blood vessels and nerves of the face
foramen spinosum?
for blood vessels and nerves of the jaw
ethmoid bone function
-form the anteromedial floor of the cranium
- the roof of the nasal cavity
-part of the nasal septum and medial orbit wall
- contains ethmoid air cells
articulations of the ethmoid bone
-frontal bone
-sphenoid bone
-lacrimal bone
-nasal bone
-maxillary bone
-palatine bone
-inferior nasal conchae
-vomer
parts of the ethmoid bone
-the cribriform plate
-the two lateral masses (ethmoidal labyrinth)
-the perpendicular plate
the cribriform plate?
floor of the cranium
roof of the nasal cavity
-has crista galli
the two lateral masses (ethmoidal labyrinth)
has ethmoidal air cells
superior and medial nasal conchae
the perpendicular plate
part of the nasal septum
sutures?
-sagittal suture
-coronal suture
-lambdoid suture
-squamous suture
what does the calvaria consist of
frontal, parietal, and occipital bones
which suture contains sutural wormian bones
lambdoid suture
fontanelles meaning
fibrous, membrane-covered gaps found when more than 2 cranial bones are juxtaposed
how many fontanelles does a newborn have, and where are they found?
6
-1 anteriorly, most prominent, rhomboid in shape, between 2 parietals and 2 frontals
-1 posteriorly, triangular in shape, between the occipital and 2 parietal
-2 mastoid
-2 sphenoid
