Neuro Flashcards
What are emergent properties of the brain
properties of whole system but not individual components e.g. consciousness
what is neocortex and paleocortex involved in
neocortex - higher thinking
paleocortex - memory and emotion
what is septum pellucidum
separates anterior lateral ventricles
where is limbic system. what it contains. involved in?
under cerebrum. contains amygdala, hippocampus, fornix etc.
5 F’s - fighting, fleeing, feeding, feeling, fucking
where is the calcarine sulcus
occipital lobe
where is lateral sulcus
between temp and parietal lobe
where is insular cortex and what involved in
deep folding inside lateral sulcus. consciousness, emotion, homeostasis
what is corona radiata of brain
sheet of axons from and to cerebrum
what is caudate nucleus and function
part of basal ganglia. voluntary movement
where is basal ganglia and what consist of
below cerebrum and surrounds thalamus. corpus striatum + substantia nigra + subthalamic nuclei
what is corpus striatum
globus pallidus and (neo)striatum
what separates L and R cerebellum and cerebri
falx cerebri, falx cerebelli
what separates cerebrum from cerebellum. What coonects the 2 cerebral hemispheres
corpus callosum and anterior and posterior white commussures
tentorium cerebelli
what is striatum
caudate nucleus + putamen
what is cerebellum peduncle
connecs cerebellum to mid brain. Sup, mid and inf fibres per hemisphere of cerebellum
what is forebrain and brainstem
forebrain - cerebrum, thalamus, hypothalamus
brainstem - midbrain, hindbrain (pons, medulla, cerebellum)
give venous sinuses of brain
see book
sup and inf sagittal, straight, confluence, transverse, sigmoid, IJ vein
what is conus medullaris
Taper end of T12-L1
what is filum terminale
strand of fibrous tissue from apex of conus medullaris to end of vertebral foramen
where lumbar puncture and in kids
L3/4
kids - L5/S1
where is SG and what is contained
lamina 2
contains - C fibres, lissauers fibres synapsing
what is ataxia and apraxia
ataxia - loss of full control of body movements
apraxia - unable to perform complex movements
what is aphasia, aphonia, dysarthria
aphasia - speech disorder
aphonia - physical inability to produce sound
dysarthria - disruption of articulation of speech
what is chorea
involuntary jerks e.g. huntingtons
what is spasticity vs rigidity
spasticity is unidirectional, velocity and amplitude dependent
spasticity = corticospinal tract damage
rigidity = extrapyramidal lesion
how detect spina bifida before birth
alpha fetoprotein in blood, USS
types of spina bifida
occulta - just vertebrae
meningocoele - meningele involvement
myelomeningocoele - neural tissue outside body
symptoms of spina bifida
bladder conrol, orthopedic issues, pressure sores, weakness in lower limbs
what is rachischisis
posterior neuropore fails to close resulting in motor and sensory deficits
how treat hydrocephalus and symptoms
treat with shunt (jugular)
symptoms - tunnel vision, headaches, convulsion, vomiting
parts of neural tube and what they become
prosencephalon - telencephalon (cerebrum) and dienceph (thalamus)
mesenceph - mesenceph (midbrain)
rhombenceph - metenceph (pons) and myelenceph (medulla)
Tell Di Mes Met My
label ventricles
see book
3rd, 4th, lateral, cerebral aqueduct, IV foramen
what does alcohol effect in neuroembryology
neural crest cell migration
what is hirschprungs diseasse
lack of ganglions in large intestine, therefore no function
astrocyte functions
BBB, removes neurotransmitters, nutrients to neurones
function of microglia
phagocytose material and debris. APC
what is BBB made of
tight endothelial junction, astrocyte foot process, basement membrane
types of neurotransmitters
AAs e.g. GABA, glycine, glutamate
biogenic amines e.g. dopamine, 5-HT, histamine
peptides e.g. dynorphin, CCK
is glutamate excitatory or inhibitory. what receptor types are there
excitatory
ionotropic and metabotropic
ionotropic - AMPA, kainate, NMDA
how does LTP occur and what happens in LTP
calcium goes through mGluRs or NMDAR.
Upregulation of AMPARs
where is gaba found. what ions does it let in
Cl-
found in spinal cord and brainstem
dopamine pathways and function
nigrostriatal - motor control (parkinsons)
mesolimbic and mesocortical - mood, arousal and reward (schizophrenia)
tuberoinfundibular - prolactin release and endocrin function
serotonin pathway function
sleep, wakefulness, mood, vomiting
label circle of willis
see book
ant post comm, ant mid post cerebral, ICA, sup ant inf post inf cerebellar, pontine, basilar, ant spinal, vertebral
what supplies spinal cord blood
anterior spinal, paired post spinal, anatastamoses between arteries (arterial vasocorona). Artery of ademkiewicz (thoracolumbar)
what arteries supplies cerebrum
outside cerebrum middle cerebral artery does majority of ant cerebrum
sagittal view - anterior cerbral artery does majority of ant cerebrum
posterior cerebral always does posterior section
symptoms of sub acute hemorrhage and cuases
thunderclap headache, rapid onset, vomiting, confusion, decrease consc
causes - trauma, cerebral aneurysm rupture in circle of willis
what removes and adds CSF
remove - arachnoid granulations at sup saggital sinus
add - ependymal cells of choronoid plexus
how many mls of CSF are there and how much produced per day
500 ml per day
125 mls of CSF
what is communicating hydrocephalus? causes
impaired csf resborp without csf flow obstruction
caused by scarring of arachnoid granulations
cause of non comm hydrocephalus
obstruction
csf composition
decrease glucose, ca, protein
increase na, mg, cl than blood
list what CNs go through what foramina
cribiform plate - 1 optic canal - 2 SOF - 3, 4, 5a, 6 foramen rotundum - 5b foramen ovale - 5c IAM - 7,8 jugular foramen - 9-11 hypoglossal canal - 12
what does pacinian, merkels, meissners, and riffini sense
riffini - temp
pacinian - pressure
merkels - press, vibration, texture
meissners - touch and vibration
what receptors are in muscle. what they sense
muscle spindle proprioceptor = length
golgi tendon organs = tension
how is stronger stimuli recognised by receptors
increase AP frequence and activation of neighbour cells
difference between tonic and phasic receptors
tonic - slow adapting, continual firing
phasic - fast, desensitises
how is acuity achieved in sensation
lateral inhibition and divergence
convergence decreases acuity
what factors affect 2 point discrimination
size of receptor field and density of sensory receptors
where does sensation go after nerve stimulated
to somatosensory cortex on post central gyrus
what is perception
sense stimuli and discriminate between different types
what happens in a sensory cortex lesion
lose 2 point discrimination, epileptic event
how orientate spinal cord
dorsal median sulcus and ventral median fissuer
modality of ascending nerves
dorsal column - light touch and conscious proprioception
spinothalamic lateral - pain and temp
spinothalamic ant - crude touch
spinocerebellar ant - golgi tendon (tension), unconscious
spinocerebellar post - muscle spindle (length), unconscious
what 2 fascicles make up dorsal column and where are they positioned. where do they start
gracile and cuneate (t6 start)
gracile is medial (sacrolumbar), cuneate lateral (cervicothoracic)
describe route of dorsal column
DRG (1) to cuneate and gracile nuclei in medulla (2), then decussates (internal arcuate fibre) and becomes medial lemniscus fibres in pons, then to ventral posterolateral nucleus in thalamus (3), then to post central gyrus
route of spinothalamic
ascends 1-2 spinal levels in lissauers fasciculus, then dorsal horn in SG(1) and decussates (via anterior white commissure) to thalamus (2) to sensory cortex (3)
what type of neuron is used in the 1st order for sensory pathways
pseudounipolar
route of spinocerebellar ant
DRG (1) then decussates in spinal cord (via anterior white commissure) then up to pons and decussates again then to cerebellum.
route of spinocerebellar post
DRG (1) then synapse with clarkes nucleus in dorsal horn (2) to cerebellum
modality of descending nerves inc extrapyramidal. damage to vestibular spinal?
lateral corticospinal - limb
anterior corticospinal - axial
corticobulbar - face and neck muscles
extrapyramidal:
ruberospinal - voluntary skeletal contraction
reticulospinal - posture and locomotion
tectospinal - automatic reactions to visual and auditory stimuli
vestibularspinal - posture maintenance. damage = loss of righting reflex and posture instability
route of corticospinal
lateral - motor cortex to internal capsule to medulla and decussate then to ventral horn
anterior - same but decussates at ventral horn
route of corticobulbar
motor cortex to internal capsul to motor nuclei of cranial nerves bilaterally
what is syringomyelia
cyst forms in spinal cord causing pain, paralysis, weakness
explain brown sequard syndrome
hemilateral lesion of spinal cord - loss of ipsilateral dorsal column therefore ipsilateral proprioception and ifne touch (no decussation). Loss of counterlateral pain and temp due to spinothalamic decussation.
what is friedrichs ataxia
sclerosis and degen of DRG, spinocerebellar, corticospinal, and dorsal columns. progressive
what is shingles symptoms
increased sensitivity and rash. dormant in DRG. can lead to post herpetic neuralgia and chronic pain.
anatomy of cerebellum
see book
vermis, ant lobe, post love, flocculonodular love
give function of cerebellar parts
spinocerebellum - vermis - error correction
vestibulocerebellum - follculonodular lobe - balance and ocular reflexes
cerebrocerebellum - lateral parts - movement planning and motor learning
what happens in damage to cerebellum and vermis
vermis damage - fall backwards
cerebellum damage - fall and decrease coordination on ipsilateral side
UMN lesion signs
increase reflex, tone, spasticity, rigidity, chorea (extrapyramidal), babinski (pyramidal)
LMN lesion signs
atrophy, fasciculations, paralysis
where are cell bodies of LMNs found in what lamnia
8 and 9
what is a motor unit
motoneurone and muscle fibre it supplies
define stretch reflex
involuntary, unlearned, repeateable, automatic reaction to a specific stimulus which doesnt require brain intact
components of stretch reflex
strech receptor, affereent fibre, integration centre, efferent fibre, effector
muscle tone in newborn
suppressed to aid birth
extrapyramidal lesion signs
akathisia (muscle restlessness), spasm, parkinsonian. Way that movements are carried out
parkinsonian symptoms
tremor (pill rolling), cog wheel rigidity, postural instability, mask like expression, bradykinesia, shuffling gait
decorticate and decerebrate
decorticate - mummy. damage to cerebrum, mid brain, thalamus, internal fibres poss
decerebrate - full exntension. brainstem damage
why fasciculations occur in LMN lesion
hypersensitive ACh receptors
what is spinal shock
damage to descending tracts leads to areflexia and flaccid which then become UMN signs. Due to release of GABA in damage
what symptoms of cerebellar dysfunction
DANISH
dysdiadochokinasia, ataxia, nystagmus, intention tremor, scanning dysarthria, hypotonia + heel shin positivity test
what romberg test and what positive meants
tests proprioception of lower body. suggests cerebellar damage
Thalamic nuclei
VPL - spinothalamic and dorsal column
VPM - trigeminal - Face sensation and taste - Makeup on Face
LGN - Cn2 - vision - lateral = light
MGN - Hearing - Medial = music
VL - cerebellum and basal ganglia - Motor
hypothalamic functions
TANHATS
Thirst and water balance, ant pit regulation, neural hormone release, hunger, autonomic regulation, temp regulation, sexual urges
what is the cause of parkinsons
nigrostriatal and SN degeneration
what is nociception
percetion of pain
how does pain thershold and tolerance vary for people
threshold same, tolerance varies
stages of nociception
transduction - activation of fibres
transmission - to CNS
modulation - CNS or other peripheral nerves can inhibit
perception
what type of pain does Adelta and C fibre feel
Adelta - mechanical
C - mechanical, thermal, chemical
properties of adelta and c fibre
a delta - sharp, stabbing, well localised, lower threshold, withdrawal reflex
C - burning, throbbing, poorly localised, higher thershold, tissue damage ongoign
how is cerebellum mostly damaged and what is parkinsons damage of
parkinsons damage to extrapyramidal
cerebellum - tumours and strokes
through what lamina do adelta C and visceral fibres travel
adelta - 1, 5
C - 1, 2 and 5
visceral - 5
explain process of pain transduction
damage to tissue releases K, prostaglandins, serotonin, bradykinin and activates nociceptor. AP occrs and substance P is released. Substance P releases histamine from mast cells
how do NSAIDs and steroids act as analgesics
NSAIDs inhibit prostaglandins
steroid inhibit IL
explain pain modulation
gate control theory. Endorphins reduce nociception
Periaqueductal grey matter in midbrain projects to nucleus raphe magnus and both mediate pain.
define chronic pain
> 3 mths and no ongoing tissue damage.
define hyperalgesia and allodynia
allodynia - non painful stimulus = pain
hyperalgesia - lowered threshold to pain.
explain process of winding up
repeated nociceptor stimulation leads to upregulation of neurones (reduced threshold and increased receptive field). Also change in somatosensory mapping
chronic pain types
nociceptive, neuropathic, visceral, FMS (fibromyalgia)
what is neuropathic pan. tgive example
sponteanous, shooting, pins and needles. not responsive to opioids.
e.g. phantom limb
what is complex regional pain syndrome type 1 and 2
type 1 - no identifiable lesion
type 2 - lesion
What is complex regional pain syndrome. give stages 1 to 3
severe continous burning pain.
1 - acute
2 - thickening skin. muscle atrophy. odema
3 - limited ROM. contractures. waxy skin
function of opioid receptor
close vocc, open K, inhibit cAMP and neurotransmission
give the 3 types of endorphin receptors and the associated endorphin
MOP - endomorphin
KOP - dynorphin
DOP - enkephalin
give exmaple of strong and weak opioid
strong - fentanyl, morphine
weak - codein
what is WHO pain ladder
1) non opioid e.g. paracetemol or NSAID, adjuvant
2) weak opioid +/- adjuvant
3) strong opioid +/- adjuvant
how treat central pain
antidepressant, AED, anasthetic, opioid
what causes inner ear deafness
teratogneic agents and infections e.g. rubella
what is coloboma and what causes
hole in structyure of eye. caused by fialure of optic stalk to fuse
give optic tract anatomy
see book
optic nerve to chiasm to tract to LGN to radiation
what happens in full lesion of optic radiation, temporal lesion and nasal lesion?
full - homonymous hemi
temporal - homonymour superior quadrantanopia
nasal - homonymous inferior quadrantanopia
what happens in midline lesion of optic chiasm
bitemporal hemianopia
what is meyers loop
temporal part of optic radiation
properties of rods and cones
rods - dark, not in fovea, converge on bipolar
what are the neurons in the eye
photoreceptors, interneurons, ganglion cells
give types of interneurons and their function
interneurons combine photoreceptor signals
bipolar, horizontal, amacrine
what is the magnocellular and parvocellular cells
both in LGN. Magno responsible for resolving motion and outlines. Parvo responsible for colour contract
give sign of fovea hyperplasia
nystagmus
what is amblyopia and give causes
decreased vision in 1 eye due to disuse in childhood
cause - strabismus (inability to focus both eyes on a object), anisometropia (refractive diff in both eyes), deprivation e.g. ptosis or cataracts
give types of strabismus and lesion causing
esotropia - inwards. CN 6 palsy
exotropia - outwards
hypertropia - upwards. CN 4 palsy
how treat amblyopia
glasses or eyepatch
waht is glaucoma
increased intraocular pressure poss cause opitic nerve damage or peripheral field defect
what is function on inner and outer hair cells of ear. where is high and low frequency heard
outer - amplification
inner - sense
high frequency at base, low at apex
how does AP in hair cells occur
bending of stereocilia opens K channels leading to depolarisation and calcium influx and neurotransmitter release to spiral ganglia neurones (afferents axons of CN 8)
what is function of olivocochlear system
regulates outer hair amplification
how is sound localised
delays and difference in volume between left and right ear
how are loud sounds transmitted
increase AP and recruitment of neighbour cells
give auditory pathway
cochlear nerve to cochlear nucleus to olivary nucleus to colliculus to MGN to auditory cortex
give causes of hearing impairment
congenital, age, infection, gentamicin, loud noise
how treat hearing loss
hearing aid or cochlear implant
what artery casues most strokes
mid cerebral
what does the PCA feed
occipital, midbrain, thalamus, half temporal
define stroke and TIA
stroke - poor blood flow to brain over 24 hours symptoms
TIA -
symptoms of temporal lobe stroke
tsate and smell, memory, superior quadrantanopia, wernickes aphasia
what is wernickes and brocas aphasia
wenickes - problem comprehending
brocas - problem talking
parietal lesion symptoms
speech, sensation, inferior quadrantanopia
symptoms of lacunar stroke
pure motor, sensory, sensorimotor, ataxic, hemiparesis
what structures involve din a POCS
brainstem, cerebellar, occipital
how investigate and treat stroke
ct or mri
treat alteplase
how can spinal cord blood supply be damaged and symptoms
cause - vasculitis, sickle cell, hypotension
symptoms - spinal shock, motorsymptoms
what is flaccid and reflex bladder. where is lesion
flaccid - lesion below T12. LMN
reflex - T12 or above. UMNL
how manage head trauma or loss of conscious
ABCD, history, exam
O2, if hypo IV glucose
what is function of reticular activating system. affected by?
regulates sleep wake cycle
affected by alcohol, senses, drugs, parkinsions, schizo, PTSD, depression, alzheimers
what is coup and contrecoup injury
coup - front brain
contrecoup - rebound
what is contrusion
bruise
what is primary and secondary insult to brain
primary - haematoma, hemorrhage, contusion
secondary - hypoxia, oedema, increased ICP
what happens in disruption of BBB?
vasogenic oedema due to protein influx, increase ICP
what is cytotoxic oedema
Na retention in cells leads to swelling and increase ICP
how is increase ICP compensated. wjhat is cushings reflex
decrease venous blood and CSF
cushings reflex - increase BP, irregular breathing, decrease HR
why might use barbiturates or propofol in increase ICp
both reduce cerebral metabolic rate of o2
symtpoms of opioid
antitussive, analgesia, constipation, hypotensive
function of mannitol
decrease cerebral oedema. osmotic diuretic
what are the 4 brain waves and when are they seen
alpha - awake and resting
beta - awake and mental activity
theta - sleeping
delta - deep sleep
what happens in locked in syndrome
loss of RAS descending pathways by lesion below pons
what is coma, brain death
coma - state of unconsciousness which patient cannot be roused from. no voluntary movement but signs of active brain
brain death - irreversible loss of all features of brain
function of sleep
allows cns to reset and memories to proces
what control sleep wake cycle
RF and hypothalamus (by inhibiting RF)
what happens in REM and non REM sleep
REM - active brain inactive body. increase RR, HR, BMR. Alpha and beta waves
non REM - inactive brain active body. neuroendocrine. decrease RR, HR, BMR. theta and delta waves
what happens to wake us up
serotonin and ACh release stimulates thalamus
what is parasomnia, hypersomnia, narcolepsy
parasomnia - sleep paralysis
hypersomnia - day time sleepiness
narcolepsy - constant hypersomnia
if loss of consciousness occurs, why?
damage to Reticular formation
give GCS
eye 1-4 - none, pain, speech, spontaneous
verbal 1-5 - none, incomprehensible, inappropriate words, confused, orientated
motor 1-6 - none, extension to pain, flexion, flexion to pain, localise pain, obey commands
symptoms of extradural hemorrhage
trauma, slow onset, lucidity then decrease consc, increasing severity headache, vomiting and confusion
subdural features and subarachnoid hemorrhage
subdural - slow onset, atrophy of brain, age, trauma, fluctuating consciousness, insidious physical or intellectual slowing
SAH - thunderclap headache, vomiting, seizures, neck stiffness
parietal dominant and non dominant features
dom - speech, logic, sensation integration
non dom - emotion, language, music/art, visioaspatial, body awareness
anterior frontal lesion
apathy, loss of personality, asocial, amoral, loss of social inhibition
temporal lesion
speech (dominant), memory
function of angular gyrus
takes written word interpretation from occipital to wernickes area
where 2 diffeerent type sof memory stored
declarative - hippocampus, cortex
procedural - cerebellum, basal ganglia
how is memory consolidated in neurones. techniques to consolidate memory?
rehearsal, association, emotion
via LTP
causes of amnesia
trauma, stroke, infection, dementia
hippocompal lesion
anterograde amnesia
define dementia and symptoms. how does delirium differ
acquired loss of brain function significant enough to affect daily function and QOL. decrease intellect, reason, personality without loss of consciousness (delirium is loss of consciousness)
symptoms - progressive loss of memory. intellect, personality, behaviour, spech, movement
causes of dementia
vascular, alzheimers, lewy bodies, drugs, fronto-temporal dementia
describe pathogenesis of AD. RF?
aB amyloid deposits, tau neurofibrillary tangles.
RF - age and female
lewy body dementia pathogenesis and symptoms
alpha synuclein amyloidosis. REM sleep behaviour disturbed, delusions, paranoia, goes on to have AD features
AD pre-dementia, early, mid, late symptoms
pre - subtle - forgetfullness, planning, apathy
early - anterograde amnesia starts (harder to learn things), loss oral and written fluency
mid - speech problems, aggression, irritability,
late - complete loss language, exhaustion, extreme apathy, poss bedridden
fronto-temporal dementia
increase tau protein, lack of empathy, disinhibiton, personality loss
normal pressure hydrocephalus symptoms
dementia, incontinence, gait
causes of meningitis
neonates - e coli
1-5 - h influenza
5-30 - n meningitidis
>30 - strep pneumoniae
what is encephalitis
viral infection of brain parenchyma
what brain part does herpes infect and symptom
infect temporal lobe, lead to seizures
what is perviascular cuffing
aggregation of lymphocytes around a BV in encephalitis
what is normal brain pressure, in coughing, and what can it get up to
normal - 0-10
coughing - 20
up to 60mmHG
what is subfalcine hernia. ischemia of?
cingulate gyrus goes under falx cerebri. ischemia of parietal, frontal, corpus callosum
what is tentorial hernia. damage to?
uncus and parahippocampus through tentorial notch. damage to CN3 and occlusion of PCA and sup cerebellar arteries
what is tonsillar hernia and damage?
cerebellar tonsils through foramen magnus, compressing brainstem. apnoea.
symptoms of increased ICP
headahce, vomiting, papilloedema - leading to pupil dilation, coma
types of brain tumours
meningioma, astrocytoma (malignant), metastases (Skin, lungs, kidney, breast, GI)
difference taste and flavour
flavour inc smell
what produces and absorbs intraocular fluid
produced - ciliary body
absorbed - schlemm (venous sinuses)
what is presbyopia
long sighted with age
what is scotomata
pathological blind spot
how test colour vision
ishihara chart
symptoms of TACS and PACS
TACS is all of HHHH, PACS is 2 of 4
hemiparesis, higher cerebral dysfunction (dysphagia, hemineglect, agnosia), hemianopia, hemisensory loss
POCS symptoms
loss of consciousness, visual disturbance, DANISH
