all Flashcards
3 flat bones that make the roof of the skull
frontal
parietal
occipital
bones of the neurocranium
frontal
ethmoid
sphenoid
occipital
parietal (2)
temporal (2)
parts of the temporal bone
petrous: ridge that houses the hearing apparatus
squamous: flat portion
bones that form the orbit (7)
sphenoid
frontal
lacrimal
ethmoid
zygomatic
maxillary
paletine
pneumatized bones - contain air spaces, cells and sinuses
frontal
ethmoid
sphenoid
temporal
3 singular bones of the facial skeleton
mandible
ethmoid
vomer
6 paired bones of the facial skeleton
maxilla
inferior nasal concha
zygomatic
palatine
nasal
lacrimal
bones of the nasal septum
ethmoid (perpendicular plate)
vomer
bones of the hard palate
maxilla
palatine (horizontal portion)
3 foramina of the greater wing of the sphenoid bone
foramen rotundum
foramen ovale
foramen spinosum
bones that make the anterior cranial fossa
sphenoid (lesser wing)
ethmoid
frontal
bones that make the middle cranial fossa
sphenoid (greater wing)
temporal (squamous and petrous)
bones that make the posterior cranial fossa
occipital
temporal (petrous)
foramina in the cribiform plate (ethmoid) give access to…
the nasal cavity
superior orbital fissure and optic canal (sphenoid) gives access to…
the orbit
which nerve passes the crista Galli/cribiform plate of the ethmoid bone
olfactory nerve
which bones does the sphenoid bone articulate with
occipital
frontal
ethmoid
vomer
temporal
parietal
zygomatic
paletine
parts of the sella turcica
anterior = tubercular sellae
posterior = dorsum sellae
middle = hypophyseal fossa
- also has anterior and posterior clinoid processes (“bedposts”)
6 processes of the sphenoid bone
2 lesser wings
2 greater wings
2 pterygoid processess (both have lateral + medial)
what 3 bones coming together make the foramen lacerum
sphenoid
temporal
occipital
what is the superior orbital fissue
cleft between the greater and lesser wings of the sphenoid bone which allow access to the orbit
parts of the brain
cerebrum: frontal, parietal, temporal and occipital lobes
cerebellum
brainstem: midbrain, pons, medulla oblongata
what are the central and medial sulcus
central: separates frontal and parietal lobes
medial: inferior to frontal and parietal lobes
which parts of the brain occupy which cranial fossae
anterior: frontal lobe
middle: temporal lobe, midbrain
posterior: cerebellum, midbrain, pons, medulla
which cranial nerves have motor branches
CN3 (oculomotor)
CN4 (trochlear)
CN5 (trigeminal)
CN6 (abducent)
which cranial nerves have sensory branches
CN1 (olfactory)
CN2 (optic)
CN5 (trigeminal)
olfactory nerve (CN I)
- sensory nerve for smell
- has bulb and tract
- pass through tiny foramina in cribiform plate to access nasal cavity
optic nerve (CN II)
- sensory nerve for vision
- gets from eye to middle cranial fossa between frontal and temporal lobes
- optic chiasm: where 2 optic nerves meet before dividing again to form 2 optic tracts
- optic chiasm is immediately anterior to pituitary gland
Oculomotor nerve (CN III)
- chief motor nerve of extra-ocular muscles
- emerges from midbrain, travels through cavernous sinus and enters the orbit via superior orbital fissure
Trochlear nerve (CN IV)
- motor nerve for the superior oblique muscle of the eye
- emerges from posterior/lateral midbrain, passes anteriorly around brainstem to enter cavernous sinus and enters orbit via superior orbital fissure
Abducent nerve (CN VI)
- motor nerve to the lateral rectal muscle of the eye
- emerges from brainstem between pons and medulla, travels through cavernous sinus and enters orbit via superior orbital fissure
Trigeminal nerve (CN V)
- has motor and sensory branches
- emerges from lateral aspect of pons
- has large sensory root and small motor root
cranial exits for major branches of trigeminal nerve
ophthalmic N (V1) = superior orbital fissure
maxillary nerve (V2) = foramen rotundum
mandibular N (V3) = foramen ovale
motor vs sensory rolls of the trigeminal nerve
motor: muscles of mastication and 4 other small muscles
sensory: cutaneous sensation of the face + oral, nasal and sinus mucosa, teeth and tongue
which nerves pass through the superior orbital fissure
occulomotor
trochlear
ophthalmic (branch of trigeminal)
abducent
how is the dura mater of the brain different than that of the spine?
it has 2 layers…
periosteal layer: outer layer - adheres to inner aspect of the cranium
meningeal layer: inner layer
where is venous blood found in the cranium
between dural sinuses - reflections/infoldings of the inner layer of dura mater away from the outer layer
roles of cranial meningies
- protect the brain
- form supporting framework for vasculature and venous sinuses
- enclose the CSF filled subarachnoid space
what are the 4 dural infoldings
falx cerebri
tentorium cerebelli
falx cerebelli
diaphragma sellae
falx cerebri location
lies in longitudinal cerebral fissure, seperates cerebral hemespheres
tentorium cerebelli location
separates occipital lobes of cerebrum from cerebellum
falx cerebelli location
inferior to tentorium cerebelli, partially separates cerebellar hemispheres
location of diaphragma sellae
suspended between crinoid processes of sella turcica, covers pitiuitary gland
what are dural-venous sinuses:
- spaces within the dura mater which are the principal venous channels of the brain
- veins from the surface of the brain empty into dural venous sinuses en route to the internal jugular vein
how does CSF get transferred to the venous system
arachnoid granulations
what are the major dural venous sinuses
superior sagittal sinus
inferior sagital sinus
straight sinus
occipital sinus
transverse sinus
sigmoid sinus
cavernous sinus
which sinuses contribute to the confluence of sinuses
straight sinus
superior serial sinus
occipital sinus
superior sagittal sinus
- at superior border of falx cerebri
- begins at crista galli, ends at confluence of sinuses
inferior sagital sinus
- at inferior border of falx cerebri
- ends as the straight sinus
straight sinus
- runs along the line of attachment of falx cerebri and the tentorium cerebelli
- starts at inferior sagital sinus and joins the confluence of sinuses
occipital sinus
- lies in the posterior border of the falx cerebelli
- ends superiorly at the confluence of sinuses
transverse sinus
- runs laterally from the confluence of sinuses in the posterior margin of the tentorium cerebelli
- continuous with the sigmoid sinus
sigmoid sinus
- continuation of the transverse sinus
- s shaped
- after it passes through the jugular foramina continues as the inter jugular vein
cavernous sinus
- located bilaterally on sides of the sella turcica on the body of the sphenoid bone
osteology associated with the tentorium cerebelli
- posterior clinoid process
- petrous portion of the temporal bone
blood supply to the brain is derived from the…
internal carotid artery and vertebral artery
path of the internal carotid artery
- starts as crevical part when it branches from common carotid A
- becomes the petrous part as it passes through the carotid canal in the petrous portion of the temporal bone
- becomes the cavernous part in the cavernous sinus and follows an S shaped path
- becomes cerebral part when it becomes intradural and gives branches to the cerebrum
what branches does the internal carotid artery divide into
anterior cerebral A
middle cerebral A
vertebral artery path to the brain
- arise in the neck from subclavian artery
- pass through transverse foramina of cervical vertebrae
- enter cranial cavity via foramen magnum
- left and right vertebral arteries meet at midline of brainstem to form basilar artery
basilar artery gives these branches:
posterior cerebral A
branches to brainstem
superior cerebellar A
anterior inferior cerebellar A
Main arteries associated with the brain
posterior inferior cerebellar A
vertebral A
basilar A
anterior inferior cerebellar A
superior cerebellar A
posterior cerebral A
posterior communicating A
internal carotid A
middle cerebral A
anterior cerebral A
anterior communicating A
borders of the orbit
anterior wall = zygomatic, frontal, maxilla
medial wall = lacrimal, ethmoid
floor = palatine
posterior wall = sphenoid bone
location of the common tendinous ring
surrounds optic canal and a portion of the superior orbital fissure
rectus muscles of the eye
4 of them: superior, inferior, anterior and posterior
origin = common tendinous ring
insertion = sclera, anterior to equator of eyeball
superior oblique muscle
origin = body of sphenoid bone
insertion = sclera, posterior to equator of eyeball
- redirected when it passes through trochlea to insert posteriorly
what is the trochlea
a ring of fascia attached to the frontal bone that redirects the superior oblique muscle
inferior oblique muscle
origin = orbital surface of maxilla
insertion = sclera, posterior to equator of eyeball
levator palpebrae superiorus
origin = lesser wing of the sphenoid bone
inserts = superior eye lid
action = elevate superior eyelid
eye muscle innervation
occulomotor nerve = superior rectus, medial rectus, inferior rectus, inferior oblique, levator palpebrae superiorus
trochlear nerve = superior oblique
abducent nerve = lateral rectus
which cranial nerves travel through the cavernous sinus
CN III
CN IV
CN VI
what makes up the zygomatic arch
the temporal process of the zygomatic bone
the zygomatic process of the temporal bone
movements of the TMJ
elevation - close mouth
depression - open mouth
protrusion - protrude chin
recursion - retrude chin
lateral movements - grinding and chewing
what is the temporalmandibular joint (TMJ)
articulation between mandibular fossa of the temporal bone and the head of the condyloid process of the mandible
borders of the infra temporal fossa
lateral wall = ramus of mandible
medial wall = lateral pterygoid plate
anterior wall = maxilla
posterior wall = mastoid and styloid process of the temporal bone
roof = inferior surface of greater wing of the sphenoid bone
how do the 3 branches of the trigeminal nerve exit the cranial cavity
ophthalmic = superior orbital fissure
maxillary = foramen rotundum
mandibular = foramen ovale
masseter features
origin = zygomatic arch at zygomatoc bone
insertion = ramus of mandible: angle and lateral surface
action = elevate and protrude mandible
temporalis features
origin = temporal fossa
insertion = coronoid process of mandible
action = elevate and retract mandible
lateral pterygoid muscle features
origin of superior head = greater wing of sphenoid
origin of inferior head = lateral surface of lateral pterygoid plate
insertion = neck of condyloid process of mandible
actions = protrude mandible and side to side movement
medial pterygoid muscle features
origin of deep head = medial surface of lateral pterygoid plate
origin of superficial head = tuberosity of maxilla
insertion = medial surface of mandible
action = elevate and protrude mandible, produce grinding motion
TMJ muscle insertion
lateral pterygoid muscle
CN V3 receives sensation from…
side of head
skin of face over mandible
lower lip
mandibular (lower) teeth
TMJ
mucosa of mouth
anterior 2/3 of tongue
main branches of CN V3 (mandibular nerve)
ariculotemporal nerve
inferior alveolar nerve
buccal nerve
lingual nerve
inferior dental plexus
mental nerve
branches to muscles of mastication
most distal branches of the 3 divisions of the trigeminal nerve
V1 = supra-orbital nerve through supra-orbital foramen
V2 = infra-orbital nerve through infra-orbital foramen
V3 = mental nerve through mental foramen
path of inferior alveolar nerve
foramen ovale - mandibular foramen - mental foramen (where it becomes mental nerve)
CN V1 receives sensation from…
scalp
skin of forehead
superior eyelid
cornea
nose
mucosa of nasal cavity and sinuses
CN V2 receives sensation from…
skin of face over maxilla
inferior eyelid
upper lip
maxillary teeth
mucosa of nose
maxillary sinuses
palate
nerves associated with the orbit
optic N
oculomotor N
trochlear N
ophthalmic N
abducent N
3 major branches of the ophthalmic nerve
nasociliary nerve
frontal nerve
lacrimal nerve
branches of the nasociliay nerve (from CN V1)
posterior ethmoidal N
anterior ethmoidal N
external nasal N
infra-trochlear N
branches of the frontal nerve (from CN V1)
supra-trochlear N
supra-orbital N*
nerves in the orbit that do NOT pass through the common tendinous ring
lacrimal N (CN V1)
frontal N (CN V1)
trochlear N (CN IV)
nerves in the orbit that DO pass through the common tendinous ring
oculomotor N
optic N
abducent N
nasociliary N
branches of the maxillary nerve (CN V2)
infra-orbital nerve
zygomatic nerve (temporal and facial branches)
anterior/middle/posterior superior alveolar nerves
route of the infra-orbital nerve
foramen rotundum - inferior orbital fissure - infra-orbital foramen
nerves that pass through the inferior orbital fissure
infraorbital nerve
zygomatic nerve
what are the cutaneous nerves of the face from CN V1
lacrimal N
supra-orbital N (top of head)
supra-trochlear N (forehead)
infra-trochlear N (between eyebrows)
external nasal N (nose)
what are the cutaneous nerves of the face from CN V2
zygomatico-temporal N (temple)
zygomatic-facial N (high cheek)
infra-orbital N (below eye)
what are the cutaneous nerves of the face from CN V3
ariculotemporal N (ear)
buccal N (cheek)
mental N (lower lip and chin)
muscles of mastication that form muscular sling
masseter
medial pterygoid
landmark for lingual and inferior alveolar nerve
between the inferior head of lateral pterygoid muscle and deep head of the medial pterygoid muscle
