Neurohistology Flashcards
Glia
Support cells that help in conduction speed, repair, and NT maintenance.
Neuropil
Network of interwoven nerve fibers and their branches and synapses, together w/ glia. Connects them both.
Function of dendrite spines:
To increase surface area
Look of nissl substance/bodies
Large, basophilic masses of free polysomes and RER.
Where are excitatory/inhibitory stimuli initiated?
Initial segment
Terminal arborization
Distal end of axon
Collateral branches
Branches of terminal arborization
Telodendria
Dilation of branch ends and contact postsynaptic cell.
Most common type of neuron
Multipolar
Where are bipolar neurons found?
In retina, olfactory mucosa, and inner ear
Where are uni/pseudounipolar neurons found?
DRG and cranial ganglia
Anaxonic neurons
Neurons in CNS that do not make APs, but regulate local electrical changes of adjacent neurons.
Anterograde transport
Carries material from nerve body to periphery
Retrograde transport
Carries material from axon terminal and dendrites to cell body.
Rate of slow transport:
Fast transport:
Slow - 0.2 to 4 mm/day. Anterograde only.
Fast - 20-400 mm/day. Anterograde and retrograde.
Glial fibrillary acid protein
Proteins that reinforce the proximal regions of astrocytes with intermediate fibers.
Perivascular feet
Processes of astrocytes that cover endothelium and modulate blood flow and provide nutrients, metabolites, wastes, between neurons and capillaries.
Oligodendrocytes
Schwann cells
CNS. From neuroepithelium.
PNS. Fron NCC.
Ependymal cells
Columnar or cuboidal cells that line the ventricles and facilitate in movement of CSF and absorption.
Choroid plexus
Folded and highly vascularized tissue in roofs of 3rd and 4th ventricles.
Removes water from BVs and releases it as CSF.
Microglia
Less in number than oligos or astrocytes.
Migratory.
Involved in immune defense in CNS.
From monocytes.
Central canal
Continuous w/ ventricles within SC and contains CSF.
Layers of cerebellar cortex (3)
Molecular layer
Purkinje cells
Granular layer
What is within the molecular layer?
Neurpil and scattered cell bodies.
What is the function of the Purkinje cell layer?
To extend dendrites throughout the molecular layer.
What is within the granular layer?
Small, densely packed neurons and a little neuorpil.
What is the archicortex?
The biologically older parts of the cerebral cortex and it is arranged in 3 layers.
Neocortex and its layers (6)
Majority of cortex. Has 6 layers: Pyramidal cells Granule (stellate) cells Cells of Martinotti Fusiform cells Horizontal cells of Cajal
What part of the hippocampus and dentate gyrus considered to be?
Archicortex. Part of the limbic system (learning, memory, social skills, etc).
Hippocampus layers (3)
Polymorphic layer
Middle pyramidal layer
Molecular layer
Dentate gyrus layers (3)
Polymorphic layer
Middle granule cell layer
Molecular layer
Mossy cells
Multipolar neurons in the hilus between hippocampus and dentate gyrus
Amyloid plaques
Amorphous, pink masses in cortex. Found in patients w/ AD.
Neurofibrillary tangles
Bunches of tau protein in patients with AD.
