An alcoholic gets rapid IV fluids for electrolyte disturbance. MRI is taken after he develops acute paralysis. What disease does he have?
Central pontine myelinolysis with paralysis, dysarthria, diplopia, and loss of consciousness; caused by rapid correction of hyponatremia
Microglia originate from what embryologic layer?
Except for microglia, all central and peripheral nervous system supportive cells originate from what layer?
What is the function of ependymal cells?
Ependymal cells make cerebrospinal fluid
Which two types of cells of the nervous system are derived from neural crest cells?
Schwann cells and peripheral nervous system neurons
Central nervous system neurons are derived from ________ (neuroectoderm/neural crest cells) whereas peripheral nervous system neurons are derived from _________(neuroectoderm/neural crest cells).
Neuroectoderm; neural crest cells
Which four types of cells are derived from neuroectoderm?
Central nervous system neurons, ependymal cells, astrocytes, oligodendroglia
What is Nissl substance, and where is it found?
It is the rough endoplasmic reticulum in the cell body and dendrites (not axon) of a neuron
Neurons are _____ (permanent/labile) cells that _____ (do/do not) divide in adulthood.
Permanent; do not
On histopathology, what is the response of astrocytes to injury known as?
What are the five functions of astrocytes?
Physical support, repair, potassium metabolism, removal of excess neurotransmitter, maintenance of the blood-brain barrier
Which cells comprise the blood-brain barrier?
What is the molecular marker for astrocytes?
Glial fibrillary acidic protein (GFAP)
In HIV-infected patients, what cell type fuses to form multinucleated giant cells?
In response to tissue damage, what do microglia transform into?
Large ameboid phagocytic cells
What is the histologic appearance of microglia?
They have small, irregular nuclei and relatively little cytoplasm and are not readily discernable in Nissl stains
What is the main function of microglia?
Phagocytosis (in the setting of tissue damage) in the central nervous system
Which cells in the central nervous system are destroyed in multiple sclerosis?
Oligodendrocytes are attacked in an autoimmune process leading to demyelination
What type of cell myelinates multiple (up to 30 each) central nervous system axons?
In Nissl stains, what types of cells appear as small nuclei with dark chromatin and little cytoplasm (like a fried egg)?
Oligodendrocytes are the predominant type of glial cell in _____ (gray/white) matter.
White; the white appearance is due to myelin
_____ (Oligodendrocytes/Schwann cells) are found in the central nervous system and myelinate _____ (one/up to 30) axon(s), whereas _____ (oligodendrocytes/Schwann cells) are found in the peripheral nervous system and myelinate _____ (one/up to 30) axon(s)
Oligodendrocytes; up to 30; Schwann cells; one
What type of cells promote axonal regeneration in the peripheral nervous system?
An acoustic neuroma is a tumor derived from which cell type?
Schwann cells; it is a Schwannoma
Schwannomas often affect which cranial nerve?
Cranial nerve VIII
Schwann cells are derived from what embryonic cell population?
Neural crest cells
Which syndrome is characterized by destruction of Schwann cells?
Guillain-Barr syndrome, which involves the acute, self-limited destruction of myelin in the peripheral nervous system
What are the four sensory corpuscles?
Meissner's corpuscles, Pacinian corpuscles, Merkel's discs, and free nerve endings
What kind of corpuscles are involved in dynamic fine touch (eg, manipulation)?
Meissner's corpuscles; these are quickly-adapting receptors
What kinds of corpuscles are located in glabrous (hairless) skin?
Meissner's corpuscles; glabrous skin includes the lips and fingertips