Head Flashcards
anterior view landmarks
supra-orbital foramen nasion glabella infra orbital foramen mental foramen mental protuberance
Name the two divisions ( and two subdivisions) of the external cranium
- neurocranium (calvaria, cranial base)
2. facial skeleton
what bones make up the orbit?
frontal maxilla mandible sphenoid lacrimal ethmoid palatine
what are the openings of the orbit?
superior orbital fissure
optic canal
inferior orbital fissure
which nerves pass thru superior orbital fissure? optic canal? inferior orbital fissure?
CN 3,4,6 V1
CN 2
V2
5 nasal bones
nasal r/l maxilla ethmoid inferior nasal concha vomer
what are the landmarks on the mandible
coronoid process condylar process head condylar process neck ramus body angle mental protuberance mental foramen
landmarks of lateral cranium
temporal fossa pterion squamous suture zygomatic arch external acoustic meatus mastoid process
landmarks of the calvaria
coronal suture sagittal suture lambdoid suture bregma suture juncture lambda suture juncture
bones of cranial base
occipital, temporal, sphenoid, maxilla (hard palate), palatine (hard palate)
landmarks of cranial base
occipital condyle foamen magnum EOP mastoid process styloid process stylomastoid foramen jugular fossa carotid canal foramen ovale foramen rotundum
describe cranial sutures
- coronal-frontal and r/l parietal
- sagittal-r&l parietal
- lambdoid- occipital ad r/l parietal
- squamous - squamous portion of temporal and parietal bones
describe cranial junctures
- bregma-intersection of coronal and sagittal sutures
- lambda - intersection of lambdoid and sagittal sutures
- Pterion- intersection of 4 bones frontal, sphenoid, temporal, parietal
3 regions of internal cranium
anterior fossa
middle fossa
posterior fossa
landmarks of anterior fossa
cribriform plate
lesser wing of sphenoid bone
landmarks of middle fossa
greater wing sphenoid sella turcica optic canal superior orbital fissure foramen rotundum foramen ovale
landmarks of posterior fossa
internal acoustic meatus
jugular foramen
hypoglossal canal
foramen magnum
CN in cribriform plate
CN 1
CN in optic canal
CN 2
CN in superior orbital fissure
CN 3 4 6 and V1
CN in foramen rotundum
V2
CN in foramen ovale
V3
CN in jugular foramen
CN 9 10 11
CN in hypoglossal canal
CN 12
CN in foramen magnum
spinal cord, vertebral artery
from external view: CN thru foramen ovale
V3
from external view: CN thru carotid canal
ICA
from external view: CN thru stylomastoid foramen
CN 7
from external view: CN thru jugular fossa
CN 9 10 11
from external view: CN thru foramen magnum
spinal cord, vertebral artery
external anterior view: CN thru supraorbital foramen
V1
external anterior view: CN thru optic canal
CN 2
external anterior view: CN thru superior orbital fissure
CN 3 4 6 V1
external anterior view: CN thru inferior orbital fissure
V2
external anterior view: CN thru infraorbital foramen
V2
external anterior view: CN thru mental foramen
V3
what does CN 7 innervate?
all facial muscles and platysma
name facial muscles
occipitofrontalis orbicularis oculi palpebral orbicularis oculi orbital nasalis orbicular oris buccinator mentalis
where does CN 7 emerge from? and divide into?
merges from the stylomastoid foramen and branches into 5divisions as it passes thru parotid gland
bell’s palsy
transient paralysis of facial muscles (usually 1/2) due to impaired CN 7
CN 5 sensory pathway
V1 = orbital and frontal region V2 = maxillary region v3 = mandibular region
trigeminal neuralgia
severe facial pain due to cn 5 impairment
most common is maxillary v2 distribution
3 meninges
dura
arachnoid
pia
layers and infoldings of dura
- external periosteal layer
- internal meningeal layer
2a. falx cerebri
2b. tentorium cerebellum
2c. falx cerebelli
describe dural venous sinuses
formed btwn periosteal and meningeal layers
large veins of brain and CSF empty into dural sinuses -eventually empty into IJV
4 structures of arachnoid matter
arachnoid matter
arachnoid trabeculae
arachnoid granulations
subarachnoid space (CSF)
describe pia matter
on cerebral cortex!
leptomeninges = arachnoid and pia
-small cerebral arteries penetrate pia into brain
list the dural venous sinuses
superior sagittal, inferior sagittal, straight, transverse, sigmoid
lobes of CNS
frontal parietal occipital temporal
parts of brainstem
midbrain
pons
medulla
regions of brain
lobes
cerebellum
brainstem
pathway/structures of ventricular system
from lateral ventricles->interventricular foramen->third ventricle->cerebral aqueduct-> fourth ventricle (then goes to subarachnoid space, to arachnoid granulations to dural venous sinuses via one way gradient)
pathway of CSG secretion and absorption
choroid plexuses in lateral 3 and 4th ventricles send csf to lateral ventricles->interventricular foramen->third ventricle->cerebral aqueduct-> fourth ventricle -> then goes to subarachnoid space, to arachnoid granulations to dural venous sinuses via one way gradient
where are the choroid plexuses? what do they produce?
lateral third and fourth ventricles and they produce CSF
absorbtion into venous system is…
one way valve! pressure gradient dependent
describe blood supply to circle of willis
R/L ICA and Basilar artery (from the veterbral artery)
describe branches of the circle of willis
ACA (anterior cerebral artery)
anterior communicating artery (connects ACA R/L)
MCA (middle cerebral artery) (same line as ICA)
posterior communicating arteries (connect MCA to PCA)
PCA (posterior cerebral artery)
7 bones that form the orbit: (rim/bowl)
rim: frontal temporal maxillary
bowl: sphenoid lacrimal ethmoid palatine
openings of the orbit and their nerves
superior orbital fissure
CN 3 4 6 V1
optic canal
CN 2
Inferior orbital fissure
V2
surface anatomy of the eye
orbit & upper eyelids(covers upper margin of iris)
conjunctiva-wraps around back of eye and lines eyelids
sclera (white) and cornea (covers iris pupil and anterior chamber)
pupil and iris
medial and lateral canthus/angles
palpebral fissure (space between upper and lower eyelid)
structures of the eye lid
meibomian gland/tarsal gland palpebral conjunctiva (more outer) inferior conjunctival sac (conjunctivitis and subconjunctival hemorrhage) bulbar conjunctiva (more inner) levator palpebral superioris (CN3) superior tarsal muscle (smaller one)
conditions of conjunctiva
conjunctivitis-pink eye/membrane is irritated
subconjunctival hemorrhage-physical trauma/capillaries break and pool behind conjunctiva
what is the meibomian gland (tarsal gland)
secretes lipid fluid to lubricate and optimize the mechanics of tear fluid and eyelids
describe job and innervation of levator palpebral superioris
elevate and retract eyelid CN3
describe job and innervation of superior tarsal muscle
smooth muscle assists with raising eyelid
sympathetic innervation
damage to levator palpebral superioris or superior tarsal muscles / nerves causes
ptosis - lazy eye
structure/pathway of lacrimal system
lacrimal gland-lacrimal lake-lacrimal punctum-lacrimal canaliculi-lacrimal sac-nasolacrimal duct- inferior nasal meatus
3 layers of the eyeball
fibrous (outer)
vascular (middle)
inner
describe fibrous later of the eye ball
fibrous - sclera (white/attachment for extra ocular muscles), cornea (transparent part, sensitive to touch V1/corneal reflex)
describe the vascular layer of the eyeball
vascular- choroid (dense vascular bed, red eye reflection), ciliary body (deep to cornea/sclera junction, attachment for lens), iris (ring on anterior surface of lens, controls amount of light entering eye)
describe the inner layer of the eyeball
inner-non visual portion, retina (optic portion: optic disc, optic cup, macula of retina, fovea centralis)
pathway of light to retina
enters cornea->aqueous humor->lens->vitreous humor->retina
what are cataracts
opacities that accumulate in the lens and decrease vision
describe aqueous humor secretion/drainage and its role in maintaining IOP (intra ocular pressure)
produced in ciliary process of ciliary body->posterior chamber of eye->anterior chamber of eye->scleral venous sinus (canal of schlemm)
if it doesnt drain and is built up it causes increased pressure on retina (glaucoma)
describe the role aqueous humor secretion/drainage in glaucoma
it is a mismatch of production/secretion and drainage–build up, blockage, slowing down of drainage = compression of retina
open angle glaucoma: stuck in the anterior chamber
closed angle glaucoma:goes back into posterior chamber
6 extra ocular muscles, actions, innervations
CN3-medial superior inferior rectus, inferior obliques
CN4-superior oblique
CN6-lateral rectus
medial and lateral rectus = side to side movement
superior and inferior rectus = lateral up and down movement
superior and inferior obliques = medial up and down movement
H test
arteries of the eye
opthalamic artery (comes off ICA) central retinal artery (comes off ophthalmic)
land marks of mandible
mental protuberance, mental foramen, body, angle, ramus, coronoid process, condylar process head and neck, mandibular foramen
nerve going thru mandibular foramen
V3
structures of TMJ (temporalmandibular joint)
head of condylar process of mandible articular disc mandibular fossa of temporal bone articular tubercle of temporal bone joint capsule
moment of TMJ to open mouth
rotation: 3 fingers
translation: more then 3 fingers pulls condylar head and articular disc towards articular tubercle of temporal bone
muscles of mastication (jaw) action and innervation
temporalis-close mouth masseter - close mouth medial pterygoid- close mouth lateral pterygoid disk head and condylar head -open mouth ALL CN5!!!
boundaries of oral cavity
oropharynx - space between upper and lower dental arches & is posterior to oral cavity
roof - hard palate (5/6) soft palate - posterior portion of the tongue(? according to outline)
floor-tongue and mylohyoid/geniohyoid muscles
what makes up the roof of the oral cavity
hard palate and soft palate
what makes up the floor of the oral cavity
tongue, mylohyoid and geniohyoid muscles
structures of the hard palate
5/6 of palate : palatine process of maxillary bone and horizontal plate of palatine bone
structures of the soft palate
1/6 of palate:
1. aponeurosis (anterior) and muscular (posterior) portions [CN 5 V2 sensory + CN 10 motor]
2. muscles : palatopharyngeus -starts in pharynx
platoglossus-starts at root of tongue
musculus uvulae
3. tonsils (palatine tonsils)
innervations of the oral region:
- soft palate
- pharynx
- sensory CN 5 V2; motor CN 10
- sensory CN 9; CN 10
- gag reflex/say ahh - want symmetrical uvula (if it deviates itll go to “strong side”)
regions of the tongue
root-posterior and attaches to hyoid and mandible, has lymph tissue
body-anterior 2/3 of tongue, tastebuds/sensory
apex-tip
inferior surface-frenulum of tongue, wharton’s ducts/submandibular openings
mass of muscles covered by mucosa
tongue
extrinsic muscles of tongue: (dont need to know intrinsic)
genioglossus - CN 12
hyoglossus-CN12
styloglossus-CN 12
palatoglossus - CN10
all muscles of tongue are innervated by .. except
CN 12 except palatoglossus (CN10)
pathology of tongue vs pathology of uvula
tongue- deviates to weak side
uvula deviates to strong side
three sets of salivary glands in oral region and their pathway
submandibular gland- in submandibular triangle -> submandibular/wharton’s ducts r/l frenulum of tongue
sublingual gland- in floor of mouth ->multiple openings in floor of mouth
parotid gland-anterior/inferior to external acoustic meatus and betwn ramus of mandible and mastoid process–>penetrates buccinator muscle –>opens in oral vestibule near upper 2nd molar _–*CN 7 facial nerve exists from stylomastoid foramen and passes thru parotid gland!
regions of the nose (7) and describe them
roof (ethmoid/cribiform plate)
septum (ethmoid, vomer, septal cartilage)
floor (maxillary bone palatine process & palatine bone horizontal process)
lateral walls (inferior nasal conchae, ethmoid{sup/midd nasal conchae}, meatus{sup inf middle– also the openings for paranasal sinsues and nasolacrimal duct})
vestibule area (opening of nose)
respiratory area (bottom 2/3 of nasal cavity warms air)
olfactory area (top 2/3 of nasal cavity has CN 1 to detect smell)
4 sinuses and their openings
- frontal - opens to middle nasal meatus
- ethmoid - opens to sup and mid nasal meatus
- sphenoid-opens to sup posterior nasal cavity
- maxillary- opens to mid nasal meatus most common sinus to be infected/largest of paranasal sinuses***
structures of external ear
auricle-pinna, tragus, lobule
external acoustic meatus
tympanic membrane - cone of light, umbo
structures of middle ear
tympanic cavity - pharyngotympanic tube/eustachian or auditory tube -(connects tympanic cavity to nasopharynx)
auditory ossicles - malleus, incus, stapes
muscles- tensor tympani, stapedius
structures of inner ear
bony labyrinth - cavity within petrous portion of temporal bone that contains structures of inner ear
cochlea-auditory role
vestibule of bony labyrinth-vestibular role -balance
semicircular canals-vestibular role
ICA direction
turns horizontal to enter temporal bone then verticle to ascend to circle of willis
vertebral artery route to circle of willis
enters skull thru foramen magnum and R L merge together to form basilar artery
Anastomosis between ECA and ICA
potential reversal of flow to provide circulation to brain if ICA is blocked off–ECA will send blood thru facial, maxillary, and superficial temporal arteries around the eye -this joins with ophthalmic artery of eye which continues up the ICA to the brain
