First aid neuro anatomy and physio Part 1 Flashcards
how to stain cell bodies?
nissl stain (stains RER)
astrocytes
- physical support
- repair
- k metabolism
- removal of excess neurotransmitter
- component of blood-brain barrier
- glycogen fuel reserve buffer
- reactive gliosis in response to neural injury
- GFAP marker
- neuroectoderm derivative
microglia
- mesoderm
- cns phagocyte
- small irregular nuclei and relatively little cytoplasm
- scavenger cells
- HIV infected microglia fuse to form multinucleated giant cells in the CNS
myelin
wraps and insulates exons
-increase the space constant and conduction velocity
oligodendroglia
each oligodendrocyte can myelinate many axons ~ 30
- neuroectoderm
- fried egg appearance
- injured in MS, PML and leukodystrophy
schwann
only myelante 1 pns neuron
- neural crest
- destroyed in guillain-barre
accoutis neuroma: schwannoma - internal acoustic meatus, if bilateral assoc NF type 2
Layers of peripheral nerves
inside out
- nerve fiber
- endoneurium surrounds nerve fiber
- perineurium surrounds a fasicle of nerve fibres)
- epineurium - dense connective tissue surounds the entire nerve (fascicles and blood vessels)
Free nerve endings
Sense: Pain and Temperature
Location: all skin, epidermis, some viscera
C-slow, unmylenated fivers
Adelta - fast myelinated
Meissner corpuscles
Large, myelinated fibers; adapt quickly
Location: Gabrous hairless skin
Sense: dynamic, fine/light touch; position sense
pacinian corpuscles
Sense: vibration, presure
Location: deep skin layers, ligaments, and joints
Large, myelinated fibers; adapt QUICKY
Merkel discs
Sense: pressure, deep static touch (shapes, edges), position sense
located: basal epidermal layer, hair follicles
LArge myelinated fibers; adapt slowly
NE
Locus ceruleus (pons)
increase in anxiety
decrease in depression
DA
Ventral tegmentum and SNc (midbrain)
increase in Huntington disease
decrease in Parkinson disease
decrease in depression
5-HT
Raphe nucleus (pons, medulla, midbrain)
Increase in parkinson
decrease in anxiety
decrease in depression
ACh
Basal nucleus of Meynart
increase in parkinson
decrease in alzheimers disease
decrease in huntington disease
GABA
Nucleus accumbens
decrease in anxiety
decrease in huntington disease
Nucleus accumbens and septal nucleus
reward center, pleasure, addiction, fear
BBB
- tight junctions between nonfenestrated capillary endothelial cells
- basement membrane
- astrocyte foot processes
carieri mediated transport: glucose, amino acids
nonpolar/lipid - diffuse
hypothalamus TAN HATS
thirst water balance adenophypopysis control (anterior pituitary) neurohypophysis release hormones hunger autonomic regulation temperature sexual urges
Organum vasculosum of the lamina terminalis OVLT
senses change in osmolarity in the hypothalamus
hypothalamus supraoptic nucleus makes?
ADH stored and released by posterior pituirtary
hypothalamus paraventricular nucleus makes?
oxytocin and released by posterior pituirtary
hypothalamus Lateral area
hunger
-destruction –> anorexia ,failure to thrice
-inhibited by leptin
shrinkkk laterally
hypothalamus ventromedial area
Satiety (feeling full)
- destruction (like in a craniopharyngioma)
- destruction cause hyperphagia
- stimulated by leptin
grow medially fatty
anterior hypothalamus
cooling parasympathetic
anterior is for arctic
posterior hypothalamus
heating sympathetic h is for hot
destruction–> poikilotherm (cold blooded)
suprachiasmatic hypothalamus
ciradian rhythm
how to treat night terros and sleep walking?
benzodiazepines
what drugs can decrease REM sleep and delta wave sleep?
alcohol, benzodiazapines and barbituates
what can decrease REM sleep only?
NE
How to treat bed wetting?
(sleep enuresis)
-oral desmopressin acetate (DDAVP) which mimics ADH
What causes the extraoccular movements during REM sleep?
PPRF paramedian pontine reticular formation/conjugae gaze center).
Duration and length of REM sleep?
Every 90 minutes and duration increases thoughout the night
Order of sleep?
BATS Drink Blood Beta Awake alpha Awake (eyes closed( theta N1 sleep spindles and k complexes N2 delta N3 beta REM
Awake (eyes open)
- alert, active mental concentration
- beta (highest frequency, lowest amplitude)
Awake (eyes closed)
Alpha
Non REM sleep stage N1 (5%)
Light sleep
-theta
Non REM sleep stage N2 (45%)
Deeper sleep, when bruxism occurs
-Sleep spindles and K complexes
Non REM sleep stage N3 (25%)
Deepest non-REM sleep (slow-wave sleep); when sleepwalking, night terrors and bedwetting occurs
-Delta (lowest frequency but highest amplitude)
REM sleep (25%)
- Beta
- loss of motor tone
- increase brain O2 use
- increase in variable pusle and BP
- Dreaming
- Penile and clitoral tumescence occur
- may serve a memory processing function
Thalmus: VPL
input:spinothalamic and dorsal comlumns/medial leminiscus
Info: Pain and temp, pressure, vibration, touch, proprioception
Destination:
primary somatosensory cortex
Thalamus VPM
Input: trigeminal and gustatory pathway
Info: face sensation and taste
Desitnation: primary somatosensory pathway
makeup goes on your face
Thalamus LGN
Input: Cranial nerve II
Info: Vision
Output: Calcarine sulcus in the occipital lobe
lateral is for light
thalamus MGN
Input: superior olive and inferior colliculus of tectum
Info: hearing
Destination: auditory cortex of the temperal lobe
M is for music
thalmaus VL
Input: basal ganglia and cerebellum
info: motor
destination: motor cortex
Cerebellum imputs:
Contralateral cortex via the middle cerebellar peduncle
Ipsilateral proprioceptive information via inferior cerebellar peduncle from the spinal cord (input nerves = climbing and mossy fibers)
Cerebellum outputs
Send information to the contralateral cortex to modulate movement
the output nerves are the:
purkinge cells –> deep nuclei of cerebellum –> contralateral cortex via the superior cerebellar peduncle
What are the deep nuclei of the cerebellum?
Dont eat greasy foods
Lateral –> medial
dentate, emboliform, globose, fastigial
Lateral lesion of the cerebellum?
voluntary movement of extremities,
when injured: propensity to fall towards injured (ipsilateral side)
Medial lesion of cerebellum?
Lesions involving midline structures:
- vermal cortex, fastigial nuclei and or flocculonodular lobe:
- truncal ataxia, nystagmus and head tilting
- may have a wide gait and deficits in truncal coordination
striatum
caudate + putamen
lentiform
putamen + globus palidus
Basal ganglia direct pathway leads to?
excitatory
movement
Basal ganglia indirect pathway leads to?
inhibitory
decreased movement
DA binds to D1 on striatum this stimulates
excitatory pathway (direct) leads to more motion
DA binds to D2 on stiatum this inhibits
the inhibitory pathway (indirect) this leads to more motion
Parkinsons disease
- degenerative disorder of CNS
assoc. lewbodies (alpha synuclein intracellular eosinophillic inclusion) - loss of DA neurons in SN (depigmentation)
TRAPS temor (pill rolling at rest) Rigidity (cogwheel) Akinesia (or bradykinesia) Postural instability Shuffling gait
Huntington disease
- AD
- Anticipation
- CAG repeats
- Caudate loss of ACh and GABA
- neuronal death via NMDA-Receptor binding and glutamate toxicity.
Choreiform movements
aggression
depression
dementia
Hemiballismus
sudden, wild flailing of 1 arm +/-ipsilateral leg
Contralateral subthalamic nucleus damage STN –> lacunar stroke
Chorea
- sudden, jerky, purposeless movements
- Damage to Basal ganglia (huntingtons)
Athetosis
-slow, writhing movements especially in fingers
-Damage to basal ganglia (huntingtons)
writhing snake like movement
Myocolnus
sudden, bried, uncontrolled muscle contraction
dystonia
- sustained, involuntary muscle contractions
- writers cramp; blepharospasm (sustained eyelid twitch)
Essential tremor (postural tremor)
-Action tremor, exacerbated by holding posture/limp postion
Genetic predisposition.
- patients self medicated with EtOH which decreases amplitude
- Treat: B blockers and primidone
Resting tremor
Uncontrolled movement of distal appendages (most notable in hands)
- tremor alleviated by intentional movement
- parkinsons disease
- occurs at res; pill rolling temor
intention tremor
slow, zigzag motion when pointing/extending toward target
cerebellar dysfunction
