neurology

Come to your rescue when injury occurs. Physical support, repair (reactive gliosis = only time you can see astrocytes w/o GFAP stain), modulate inflammation since brain swelling is bad. Derived from neuroectoderm.

Munchers (phagocytes), derived from mesoderm. With tissue damage, they become large & engorged (ameboid). Little cytoplasm, plus small, irregular nuclei.

Myelinate multiple CNS axons (up to 30 each). Small nuclei & little cytoplasm. Destroyed in MS.

Myelinate 1 PNS axon. Destroyed in Guillain-Barre syndrome. Derived from neural crest cells.

RER. Found in dendrites & cell bodies of neurons, but not in their axons.

Detect dynamic touch (e.g. manipulation); fast adaptation. Found in hairless (glabrous) skin... so, a massage feels better on your back than your forearms.

Slowly adapting; detect static touch. (Meissner's vs. Merkel's: Merle is old & static.) Found in hair follicles (b/c old men are hairier).

Vibration in pressure. Found in joints, ligaments, deep skin layers.

Inc'd norepinephrine, dec'd serotonin.

Decrease = Parkinson's; increase = schizophrenia.

Alzheimer's, Huntington's

Vomiting center (area postrema), OVLT (for osmolarity). Both signal to hypothalamus.

• Makes ADH (Vasopressin)
• Mnemonic = ASOP: ADH Supraoptic, Oxytocin Paraventricular.

Makes oxytocin

Satiety; stimulated by leptin (circulates in adipocytes)

Sympathetic output (watch your back), heating

Sexual urges

Don't eat greasy foods: dentate (fine motor), emboliform, globose (spinal cerebellum), fastigial (balance - vestibulocerebellum; truncal posture)

Bilateral amygdala lesions: disinhibited, hypersexuality, hyperorality

Wernicke-Korsakoff syndrome. Wernicke's encephalopathy = reversible: confusion, ataxia, ophthalmoplegia. Korsakoff's psychosis = irreversible: confabulation due to amnesia -- so you don't know you're making things up.

Cortex

MLF

CAG repeats on chromosome 4. Lose GABA neurons from caudate nucleus (makes sense, since caudate = cognitive while putamen = more motor). Depression, dementia, chorea.

Wild flailing of 1 arm. Contralateral subthalamic nucleus lesion --> internal globus pallidus is no longer excited as much --> less tonic inhibition of thalamus.

Cerebellar dysfunction. Zigzag motions when pointing toward a target.

Lateral medulla, PICA. Sx: nausea/vom/vertigo (vestibular nuclei), dysphagia & palate droop (CN's 9 & 10), ALS -- ipsilateral face, contralateral body, ipsilateral Horner's & ataxia

Locked-in syndrome: corticospinal & corticobulbar tracts, also PPRF in pons - but can do vertical gaze b/c that's midbrain (superior colliculus).

APKD, Ehlers-Danlos, Marfan's, HTN (Charcot-Bouchard), smoking

• Lateral ventricle = caudate
• 3rd = hypothalamus
• 4th = pons

Colloid cyst = columnar epithelium, mucin-producing. Cysticercosis = Tenia solium. Echinococcus = dog feces

Cerebral hemispheres. Astrocytes stain for GFAP (just like pilocytic astrocytoma in kids). Bizzare, pleomorphic, pseudopalisading tumor cells; central necrosis and hemorrhage.

Arises from arachnoid cells. Whorled pattern of spindle cells; psammoma bodies (calcification).

Often frontal lobe, fried-egg appearance (round, dark nucleus & clear cytoplasm). Slow-growing & relatively rare.

Lose temporal halves of visual fields, which means lose nasal halves of retina -- the crossing fibers at optic chiasm. From pituitary adenoma or craniopharyngioma (both derivatives of Rathke's pouch).

Posterior fossa (ex. cerebellum). Astrocytes stain GFAP & form Rosenthal fibers -- eosinophilic corkscrew fibers. Benign; good prognosis.

Cerebellar; highly malignant. Can compress 4th ventricle. Ages 4-8. Rosettes: hyperchromatic nuclei, little cytoplasm.

Poor prognosis, usually roof of 4th ventricle. Perivascular pseudorosettes.

Associated with von Hippel-Lindau, usually cerebellar (+ retinal angiomas in von Hippel-Lindau). Can make EPO.

• Decrease aqueous humor secretion: alpha-agonists (epinephrine, brimontidine) or beta-blockers (betaxolol, carteolol, timolol).
• Increase outflow into canal of Schlemm: protaglandin (latanoprost) or cholinergics -- pilocarpine (emergencies), carbachol, physostigmine, echothiophate

Agonist at opioid kappa receptors, but partial agonist at mu. (Orphan doesn't have a mom.) Use for pain; causes less respiratory depression than full agonists.

"Tram it all in"... inhibits serotonin & NE reuptake, also very weak opioid agonist.

• Phenytoin = prophylaxis
• Benzodiazepines for acute

Blocks Na+ channels. Living Large: Gum hyperplasia, double vision, induces CYP450, megaloblastic anemia, ataxia. Also peripheral neuropathy, hirsutism.

Neural tube defects (not for use in pregnancy), rare liver toxicity, weight gain.

Teratogen, agranulocytosis & aplastic anemia (like chloramphenicol), induces CYP450

Absence seizures only. GI distress, SJS, urticaria.

All seizure types except absence. SE: SJS.

It's not HIPP to have lupus: hydralazine, isoniazid, phenytoin, procainamide.

...drug is less soluble in the blood.

...it is more lipid-soluble (can penetrate BBB more readily)

Can't recognize faces

Unaware of your own sensory & motor deficits -- large lesion of non-dominant parietal lobe

Deny ownership of half of body

Reading impairment

Can't follow a verbal command -- ex. can brush teeth spontaneously, but not after being asked to imitate someone who's brushing his/her teeth

CN III (blown pupil) & midbrain cerebral peduncle (hemiplegia)

Cerebellar tonsils go thru foramen magnum; often asymptomatic.

Abnormally small posterior fossa: Cerebellar vermis & medulla go through foramen magnum. Associated with myelomeningocele & syringomyelia (crossing spinothalamic fibers).

Abnormally large posterior fossa: 4th ventricle expands, with ependymal cyst

Midbrain, anterior to substantia nigra. Contains descending fibers from corticospinal & corticobulbar tracts.