Head FINAL Flashcards
branches of the facial nerve
-temporal: Controls your forehead muscles.
-Zygomatic: Helps you close your eyes.
-Buccal: Allows you to move your nose, blink and raise your upper lip and corners of your mouth to make a smile (buccinator)
-Marginal mandibular: Draws your lower lip down (like a frown) and travels through your middle ear to help you respond to loud noises.
-Cervical: Controls movement in your chin and lower corners of your mouth.
Bells Palsy
-facial nerve
-viral infection- HSV1 - peripheral (in ex at least)
-parotid tumors- ipsilateral upper and lower
-central/cortical lesion- lower half of face weakness of contralateral side
-peripheral lesion- upper and lower weakness of ipsilateral side of face
tongue
-posterior 1/3- bitter -> glossopharyngeal (taste and general)
-lingual nerve is branch of V3 - 2/3 of tongue (sensation)
-facial nerve- anterior 2/3 tongue- taste
-hypoglossal- motor
facial arterial supply
-external carotid artery
-branches: facial, temporal, maxillary
-maxillary -> middle meningeal
-facial artery has submental, superior and inferior labial arteries
-superior labial artery- concern with upper vermillion border bleed -> if scabs and falls off it can exanguate
subaponeurotica (areolar) tissue
-permits venous blood flow from the dural sinuses to the venous vessels of scalp
-emissary veins- potential route for infection
-abscess, thrombosis of superior sagital sinus, infection, purulent
-laceration to scalp can cause acute blood loss anemia
-superior sagittal sinus bleed -> slow bleed -> subdural hematoma
subdural hematoma
-bleeding within meninges- below dura mater in the subarachnoid space
-superior sagittal sinus- slow bleed
-tears to bridging VEINS MC
-banana shape
-slow deterioration
-can cause cardiac arrhythmias -> medulla oblongata injury
-white shade on image - blood
-gray shade- a chronic bleed -> maybe an alcoholic who hit their head and dont remember -> hygroma -> CSF
-edema causes shift
-can drain in ER in an emergency bc its venous and lower pressure compared to epidural
fontanelles
-window to intracranial pressure
-depressed- hypovolemic, dehydrated, pancreatitis, blood loss, decrease IOP
-bulging- tumor, fluid overload
-sunset sign- iris/pupil is down at bottom of the eye -> hydrocephalus
-anterior, sphenoid, mastoid, posterior fontanelles
cribriform plate
-base
-can easily injury brain -> abrasion, contusion, laceration
-rhinorrhea -> CSF -> infection back up into brain
-no NG tube for basilar skull fracture or facial trauma -> you can put tube through cribriform plate and into the brain
-cribriform plate fracture -> ipsilateral olfactory loss
arachnoid mater
-suspends brain in cranial cavity
-collagen and elastin fibers
-subarachnoid space is beneath -> CSF that cushions brain
subarachnoid bleed
-wispy
-rupture of saccular aneurysm
-meningeal irritation, severe headache, stiff neck, often loss of consciousness
CSF
-water, protein, salts
-cushions CNS
-made in largest 2 ventricles of brain
-medium for nutrients and waste products to diffuse into and out of brain
-can drain to external passageway (can be pushed into spinal cord) if ICP is high -> eval target or halo sign
-8% of cranial space
cranium
-brain 80% -> cerebrum, cerebellum, brainstem
-brain receives 15% CO, 20% O2 -> unconscious within 10s and death in 4-6 mins without blood
-CSF 8%
-12% blood vessels and blood
cerebrum
-conscious though
-personality -> Frontal
-speech
-motor control
-visual
-auditory
-tactile perception
-parietal -> motor and sensory, memory and emotion
-occipital -> sight
-temporal -> long term memory, hearing, speech, taste, smell
splitting of the brain
-falx cerebri- divides cerebrum into right and left hemispheres
-central sulcus- fissure splitting it into right and left -> each hemisphere controls opposite side of body
-tentorium- fibrous sheet within occipital region
-brain stem perforates through incisura tentorium cerebelli
-oculomotor nerve travels along tentorium to front
-left hemi -> math and language interpretation (occipital) , writing (parietal), speech (frontal)
-right hemi -> non verbal imagery
basilar fracture
-fracture to bones forming base
-occipital around foramen magnum
-sphenoid
-temporal
-roof of orbit
-CSF rhinorrhea or otorrhea
-pterion fracture -> middle meningeal artery lies below in lateral calvaria -> epidural hematoma -> death
emissary veins
-loose connective tissue of scalp -> danger area
-infection can spread into cranial cavity via emissary veins -> meninges
-can cause black eyes -> spreads to eyes and nose
-cant spread to neck
occlusion of cerebral veins and dural venous sinuses
-from clots, venous inflammation, or tumor
-facial veins connect to cavernous sinus via superior ophthalmic veins
-thrombophlebitis of facial vein -> infected thrombus into cavernous sinus -> thrombophlebitis of cavernous sinus
fracture of cranial base
-cranial base fracture usually tears dura -> CSF leak
-internal carotid artery may be torn -> arteriovenous fistula within cavernous sinus
-arterial blood rushes into cavernous sinus -> overfloods into ophthalmic veins -> pulsating exophthalmos
-chemosis
-concern for oculomotor, trochlear, V1, V2, and abducens
epidural hemorrhage
-Bleeding between dura mater and skull
-Involves arteries- Middle meningeal artery most common
-Rapid bleeding and reduction of oxygen to tissues
-Herniates brain toward foramen magnum
-hematoma -> talking and fine -> all the sudden they arnt -> death
-football- self enhancing
-shift > 5mm -> problem
-loss of consciousness -> lucidness -> coma
brainstem
-central processing
-communication junction among - cerebrum, spinal cord, cranial nerves, cerebellum
-midbrain
-pons- communication between diff parts of brain, sleep
-medulla oblongata- breathing, cardiac, BP
midbrain
-Upper portion of brainstem
-Structures
-Hypothalamus- Endocrine function, vomiting reflex, hunger, thirst, Kidney function, body temperature, emotion
-Thalamus- Switching center between pons and cerebrum
-thalamus is Critical element in Ascending Reticular Activating System (A-RAS) -> ESTABLISHES CONSCIOUSNESS
-thalamus is Major pathways for optic and olfactory nerves
-Associated structures
CNS circulation
-arterial:
-4 major arteries- 2 internal carotid arteries from common carotid AND 2 vertebral arteries
-circle of willis- internal carotids and vertebral arteries -> encircle the base of brain
-venous:
-venous drainage occurs through bridging veins
-bridge dural sinuses
-drain into internal jugular veins
blood brain barrier
-less permeable than elsewhere in body
-DOES NOT allow flow of interstitial proteins
-Reduced lymphatic flow
-Very protected environment
-Blood acts as irritant resulting in cerebral edema
-NO highly charged, large, not lipid soluble can go through
-hepatic disease- fugal flow -> reverse flow ends up into systemic circulation before going through liver -> ammonia -> hepatic encephalopathy
-edema when blood brain barrier abnormal -> irritation of parenchyma -> high ICP
cerebral perfusion pressure
-ICP usually less than 10 mmHg
-MAP must be at least 50 mmHg to ensure adequate perfusion
-at least MAP 65 and higher than ICP
-ICP > 20 danger zone
-CPP- Pressure moving blood through the cranium
-CPP = MAP - ICP
-if ICP is higher than MAP -> we cant perfuse -> anoxia
-go up on MAP or go down on ICP -> better flow
-ex. raise the BP and catheter into ventricle to remove pressure
-rapid increase in ICP - herniation at 60
-pressure on the pons
corpus callosum
-mediator
middle cerebral artery
-most of lateral brain -> parietal, temporal, frontal
-contralateral hemiparesis
-contralateral hypesthesia
-ipsilateral hemianopsia*
-gaze preference towards side of lesions
-agnosia
-aphasia*
-weakness in arm and face
-hemiparesis (upper limb)*
posterior cerebral
-occipital and temporal
-cortical blindness
-visual agnosia
-AMS
-impaired memory
-dizzy
-ataxia
-hemiparesis
-hemianopsia
basilar
-brain stem and cerebellum
-vertigo
-nysatgmus
-diplopia or double vision
-ipsilateral cranial nerve deficit with contralateral motor deficit
-dysphagia
-syncope
-ataxia*
-breathing
-balance
-nystagmus
anterior cerebral artery
-cerebrum (not occipital!)
-most common aneurysm
-primitive reflexes
-AMS
-impaired judgement
-gait
-urinary incontinence
-hemiparesis (inferior limbs)*
cerebellar artery
-headache
-fever
-vomiting
-cerebellar signs
RAS
-regulates respiration
-HR
-peripheral vascular resistance
-injury if prolonged waking state
oculomotor nerve
-extrinsic eye movement
-superior, medial, inferior rectus AND inferior oblique (up, down, lateral)
-parasympathetic -> contraction of lens and ciliary muscle
PALSY-
-ptosis (eyelid droop) -> paralysis of levator palebrae superioris
-dilated pupil
-no up, down, or lateral movement -> eye is down and out
-no light reflex
-no lens adjustment -> ciliary muscle paralysis
-rapid ICP increase (epidural or subdural hematoma) -> opthalmoplegia
-posterior cerebral and superior cerebellar artery, injuries, infections, tumors
-eyes sluggish -> dilated -> then fixed
trochlear
-extrinsic eye movement
-superior oblique- depresses eye
-looking down and towards nose
-high ipsilateral eye
PALSY
-diplopia when looking down
visual field defect
-optic nerve- loss of vision ipsilateral side
-chiasm- loss of peripheral vision
-right tract- right eye loss of nasal side, left eye loss of temporal side
-left tract- left eye loss of nasal side, right eye loss of peripheral side
abducent nerve
-stretched with ICP increase
-brain tumor
-paralysis of lateral rectus msucle
-medial deviation of affected eye
-adduction
trigeminal nerve
-trauma, tumor, aneurysm, meningeal infection
-paralysis of muscles of mastication -> mandible towards side of lesion
-loss of general sensation
-loss of corneal reflex and sneezing reflex
-trigeminal neuralgia- maxillary and/or mandibular divisions -> MC artery superior cerebellar artery SCA
cornea reflex
-ophthalmic and facial nerve damage
injuries of vestibulocochlear nerve
-tinnitus
-vertigo
-loss of hearing
-acoustic neuroma
glossopharyngeal nerve lesions
-usually part of jugular foramen syndrome
-absent gag reflex (afferent is glossopharyngeal and efferent is vagus)
spinal accessory nerve
-paralysis of ipsilateral SCM
-impairment of rotation ot contralateral side
-unilateral inability to shrug shoulder
-winging of scapula at rest
valgum and varum
-gum is knee together and larger angle
-rum- knees together and smaller angle
injury to hypoglossal
-paralysis to ipsilateral half of tongue
-dysarthria
-shrunken and wrinkled
-tongue deviates towards paralyzed side
-horseness
diffuse brain injury
-stretching placed on axons
-types:
-concussion- nerve dysfunction without physical injury -> can lose consciousness, confusion, event amnesia
-moderate diffuse axonal injury - same but with minute bruising of brain, can also have basilar skull fracture
-severe diffuse axonal injury- brainstem injury
focal brain stem injury
-specific location in brain
-cerebral contusion
-intracranial hemorrhage -> epi and subdural
-intracerebral hemorrhage
-hemiplegia, weakness, seizures
diffuse brain injury: severe
-brain stem injury
-high mortality
-prolonged unconsciousness
-cushing’s reflex- increase BP, bradycardia, erratic respiration
-decorticate* (flex) and decerebrate (extend) posturing
-AMS - personality, amnesia, orientation
compensation/decompensation
-low BP - poor cerebral perfusion
-high BP - increase BP
-Compensation for pressure: hypoventilation- cerebral vasoconstriction -> cerebral anoxia but lowers ICP
-Decompensation for pressure: hyperventilation- vasodilation increase blood flow but increase ICP
-injury -> edema -> increase ICP -> compression of arteries -> decrease blood flow -> edema around dead tissue -> increase ICP -> CO2 increase -> vasodilation -> increase ICP -> death
upper brainstem injury
-vomiting without nausea -> projectile
-AMS
-pupillary dilation
-increase BP
-bradycardia -> vagus sitmulation
-cheyne stokes respirations
-pupils are small and reactive
-decorticate posturing **
medulla oblongata injury
-respiratory
-cardiovascular
-BP disturbance
cortical disruption
-amnesia
-AMS
-retrograde - can remember before
-ante- cant form new memories- repetitive questioning
middle brainstem injury
-widening pulse pressure
-increasing brady
-CNS hyperventilation- deep and rapid
-bilateral pupil sluggishness or inactivity
-decerebrate posturing
lower brainstem injury
-pupils dilated and unreactive
-ataxic respirations/pulse - erratic with no pattern
-ECG changes
-hypotension
-loss of response to painful stimuli
