MacFearing Nerve Tissue Questions
Grey matter areas in the CNS are made up of this
What are neuronal cell bodies and glial Cells?
Which adrenergic receptor ignores NE like a girl at a bar ignores a guy wearing a fedora?
What are beta-2 receptors? (I used to wear a fedora)
Beta-2 receptors cause bronchodilation and relaxation of vascular smooth muscle cells, especially in skeletal muscle
This type of incontinence happens with a lesion above pons
What is urge incontinence?
Path is normal except brain cannot send inhibitory signal to get patient to the bathroom
Structure located along the lateral wall of lateral?
What is the caudate?
Caudate lies next to putamen, separated from lentiform nucleus by anterior arms of genu, lentiform nucleus is separated from thalamus by posterior arms of genu
Ronsenthal fibers on tumor histology slide generally mean this?
What is that tumor is slow-growing?
Rosenthal fibers indicate slow growing tumors, and are common in pediatric/adult benign tumors and pilocytic astrocytoma (but they can be present in many tumors).
Myelinated internodes in the PNS are made up of this
What are the investing layers of Schwann cell membranes?
This is the alpha-2 agonist used to treat hypertension by decreasing sympathetic tone by inhibiting release of NE (among other mechanisms)
What is Clonidine?
This type of reaction to noxious stimuli could happen after Dr. Erickson's son drops you out of his helicopter and you suffer a C-spine injury
What is autonomic dysreflexia?
Rxn to noxious stimuli, which is often a full bladder (urine retention). Treatment is to remove noxious stimuli (catheterization).
This imaging finding is suggestive of ischemic event
What is "blending" of white and grey matter in imaging? (Cytotoxic edema)
Vascular leak/inflammation that results from ischemia/infarction causes lack of appearance of differentiation on imaging
Vasogenic edema is from neovascular proliferation from tumors, or increased leak from infection such as an abcess
What is 12 months old?
Review developmental milestones, i'm not writing them all out here
These aspects of nerve conduction are affected by myelin sheathing
What are the speed and fidelity conduction?
Cocaine's two mechanisms of action
What are local sodium-channel blocker and NET blocker?
Why aren't alpha-1 agonist used for stress incontinence anymore?
What are strokes due to hypertension?
An emergent cause of hydrocephalus in lateral ventricles only
What is a colloid cyst (blocking foramen of monro that drains to third ventricle)
Choroid plexus -> lateral ventricles -> Foramen of Monro -> Third ventricle -> Cerebral aqueduct -> Fourth Ventricle ->
Magendie or Lushka, central canal (to surround spinal cord/cauda equina)
or
roof of ventricle -> arachnoid granulations -> dural venous sinuses
Reason that Fosphenytoin is better rescue medication for status epilipticus than Phenytoin
What is that it does not need to be injected with dangerous vehicle, and that it is readily converted to phenytoin by resident phosphatases once in tissues.
This type of glial cell is primarily found in white matter; its function is to remove excess extracellular K+ that is released during impulse conduction
What are fibrous astrocytes?
The reason a guy with an enlarged prostate has become dizzy after starting Prazosin
What is that Prazosin is an alpha-1 antagonist, so the patient has become hypotensive?
Alpha-1 receptors activate Gq proteins that cause vascular smooth muscle cell contraction via IP3; increase vascular resistance, and therefore BP
Important questions to ask a young patient with incontinence/difficulty voiding urine
What are whether they have had visual changes or changes in the dexterity/strength of their hands recently?
MS triad!
Typical imaging finding after global ischemia
What are symmetrical watershed infarcts?
Ex: Damage between ACA and MCA areas after septic shock
This is the most common PRIMARY brain tumor in adults
Glioblastoma (Grade 4 astrocytoma)
Mets are most common brain tumors in adults, but glioblastoma is most common PRIMARY tumor
This type of ependymal cells are only found in the third ventricle, and are connected (primarily) with other ependymal cells with tight junctions, as opposed to the belt desmosomes that connect typical ependymal cells.
What are tanycytes?
These types of receptors activate Gq proteins
What are M1, M3, M5, and Alpha 1
(Gi = M2, A2, D2 (MAD2))
Gs= Beta
Three W's of normal pressure hydrocephalus
What are wet, wobbly, and whacky?
Wet (incontinence)
Wobbly (Gait issues)
Wacky (Cognitive changes)
Reversible if caught early
Artery/ventricle that are visible on axial CT/MRI at level of (middle) cerebellar peduncles
What are 4th ventricle and basilar artery?
Reversal agent for Succinylcholine
what is trick question, succinylcholine is a depolarizing NMJ blocker, so no reversal until pseudocholinesterase breaks the drug down and NMJ receptors return from their refractory periods! Neostigmine can be used to reverse non-depolarizing NMJ blockers (Pancuronium) and Physostigmine (cholinesterase activity) can reverse antimuscarinic toxicity (anticholinergic toxicity i.e. atropine)