Neurology Flashcards
what does the neural plate develop into?
neural tube and the neural crest cells
what does the notochord become?
nucelus polposus and eventually the intervertebral discs
what are the alar and basal plates?
alar- dorsal-sensory
basal-ventral-motor
what findings do you get with neural tube defects?
when neuropores fail to close during 4th week so you get opening between amniotic fluid and spinal canal. high AFP and high acetylcholinesterase (except spina bifida occulta- normal AFP)
what are the types of neural tube defects?
- spina bifida occulta- hole in neurpore, but no herniation so dura intact- tuft of hair or sacral dimple
- meningocele- meninges herniate, but no neural tissue
- myelomeningocele- meninges and neural tissue
- myeloschisis- exposed neural tissue with no meningeal or skin covering
- ancencephaly- failure of rostral neurpore to close so no forebrain
- holoencephaly- failure of right and left hemispheres to fuse (5-6 weeks)
what is the difference between type 1 and type 2 chiari malformations?
- ectopia of the cerebellar tonsils
2. vermis and tonsils through foramen magnum and stenosis of aqueduct
what is a dandy walker malformation?
agenesis of cerebellar vermis so get big 4th ventricle, non communicating hydrocephalus, spina bifida
what are the symptoms of a syringomyelia?
cape like loss of pain and temp sensation upper extremities, fine touch usually preserved
what are astrocytes?
glial cells- support, repair, extracellular K buffer, remove excess neurotransmitter
-derived neuroectoderm, GFAP is marker
where is myelin made?
oligodendrocytes in the CNS and schwann cells in the PNS
what types of cells are affected in guillian barre? what about multiple sclerosis
- Schwann cells in the PNS
2. Oligodendrocytes in the CNS
what are the three layers of the meninges?
- Dura mater (mesoderm)
- Arachnoid mater (neural crest)
- Pia mater (neural crest)
Epidural space (between skull and dura-blood vessells and fat)
CSF runs between arachnoid and pia
what makes up the blood brain barrier?
astrocyte foot process, tight junctions between non fenestrated capillary endothelial cells and basement membrane
- non polar lipid soluble get through rapidly with diffusion and
- glucose and AA’s get through with carrier mediated transport
what does the preoptic nucleus in the hypothalamus do?
thermoregulation and sexal urges-, GnRH (when the neurons don’t migrate, you get Kallman’s syndrome)
what are beta waves?
awake with eyes open, high frequency, low amplitude
what does the thalamus do? VPL and VPM?
major center for all ascending sensory information
VPL-spinothalamic and medial meniscus/dorsal column
VPM-gustatory and trigeminal
-all go to primary somatosensory cortex
what goes the lateral geniculate nucleus do?
all from CN2, optic tract, optic chiasm- goes to calcarine sulcus
medial geniculate nucleus?
hearing, everything from superior oliver and inferior colliculus of tectum
what does the ventral lateral nucleus do?
everything from basal ganglia and cerebellum- goes to motor cortex
what are the 4 dopaminergic pathways?
- Mesocortical- negative symptoms
- Mesolimbic- positive symptoms
- Nigrostriatal- decreased activity gives extrapyramidal symptoms-dystonia, akathisia, parkinsonism, tardive dyskinesia
- Tubuloinfindibular- dec activity= inc prolactin, dec libido, inc galactorrhea, gynecomastia
Is cerebral perfusion pressure more controlled by CO2 or O2?
CO2 until you get O2 less than 50mmHg, the CPP is proportional to pCO2 until it gets over 90mmHg
where is CSF made? where does it drain?
ependymal cells of choroid plexus
-drains into the arachnoid granules and then into the dural venous sinuses
what does the pineal gland do?
melantonin secretion and circadian rhythm
what are the vagal nuclei?
- nucleus solitarius- visceral sensory (taste, gut distension, baroreceptors) 7, 9, 10
- nucleus ambiguus-motor for the pharynx, larynx 9,10,11
- dorsal motor nucleus- autonomic (parasym) to heart, lungs, upper GI
at what vertebrae does the spinal cord terminate?
L1-L2
where do the eyes look when there is a lesion? where do the eyes look for seizures?
lesion- toward
seizures-away
what is a common lesion seen in MS?
medial longitudinal fasiculus, can’t adduct the eye with the side of the lesion and the contralateral eye gets nystagmus with abduction