Ojeman - introduction Flashcards
Define: Cortex, Grey Matter, White Matter, Thalamus
What is the pathway in Essential Tremor syndrome?
Cortex (bark) - grey matter, mostly on the cerebral cortex.
Thalamus (inner chamber) - area of grey matter in the cerebrum, buried on top of the brainstem. Oscillations in the nuclei of the thalamus create the muscle movements that create the tremor in ET. The tremor information network begins in the olive, spreads through the cerebellum, and reconvenes in the thalamus, which is the target site for therapy (DBS, destruction).
At the level of the individual neuron, what structure(s) are considered afferent? Efferent?
Afferent - dendrites
Efferent - axon
**Directionality determined by relationship from the cell body.
What is the theory of dynamic polarization (and who invented it for a bonus)?
That signals are transmitted through the dendrites to the cell body, then down the axon. (Cajal)
What is the neuron doctrine?
That the neuron is a distinct anatomic and physiologic unit, responsible for the transmission of information. (Cajal)
What is Hebb’s postulate?
“Neurons that fire together wire together.” Or precisely, “When an axon in cell A is near enough to excite cell B and repeatedly and persistently takes part in firing it, some growth process or metabolic change takes place in one or both cells such that A’s efficacy in firing B is increased” Pavlov’s dog is an example.
What did Kandel’s studies prove in 2000?
That gene expression changes in the brain can be effected by experiences.
VITAMIN C (not discussed in this lecture at all)
V-Vascular: This category includes ischemic and hemorrhagic strokes, and their etiologies.
I-Infectious: Bacterial, fungal, viral, and parasitic infections of the nervous system and its lining.
T-Traumatic: Physical injury to the brain, spinal cord, peripheral nerves, and their protective linings.
A-Age-Related/Degenerative: Examples include Parkinson’s disease, Alzheimer’s disease, and Prion disorders.
M-Metabolic/Nutritional/Toxic: Examples include Wernicke-Korsakoff syndrome, Central Pontine Myelinolysis, and Lead poisoning among other entities.
I-Inflammatory conditions includes demyelinating disorders such as Multiple Sclerosis.
N-Neoplastic disorders include brain tumors, tumors of the spinal cord, tumors of the lining of the nervous system (such as meningioma), and tumors of peripheral nerve.
C-Congenital and Developmental Disorders include conditions such as neural tube defects, and perinatal injuries such as germinal matrix hemorrhage.
Essential Tremor
Can treat pharmacologically (Propanolol, Primadone) but is often not tolerated. DBS stimulation calms the tremor, and involves an implantable device on the chest wall, inserting into the brain. Alcohol will calm the tremor, not a great treatment therapy. genetic predisposition (50% have a 1st degree relative with the condition).
Broca’s area
damage causes problems with language. Discrete area in the left hemisphere:
“Pars triangularis and pars opercularis of the inferior frontal gyrus of the dominant hemisphere”
Removal of hippocampus (seahorse) bilaterally?
Anterograde amnesia
Brodmann’s areas
52 different areas, originally defined histologically based on the pattern of the IV different layers of the cortex
Precentral gyrus stimulation (in front of the central sulcus)
movement
Stimulation behind the central sulcus
tingling
What is somatotophy?
Physical mapping of the cerebral cortex based on stimulation–>reaction. Leads to the homunculus.
Decussation
“in the form of an x” Refers to the crossing of fibers from the L/R hemispheres leading into the spinal column.
