Neurohistology
neurofilaments
Fine thread-like structures that form a matrix in the cytoplasm; they provide support for the cell membrane and maintain the shape of the neuron.
Nodes of Ranvier
Gaps in the myelin sheath to which voltage-gated sodium channels are confined.
Pacinian corpuscles
Skin mechanoreceptors that respond to deep pressure and vibration
grey matter
The portions of the central nervous system that are abundant in cell bodies of neurons rather than axons. *Unmyelinated.* Light on staining b/c no myelin
Scwann cells
Type of Neuroglia, found in the PNS, produce myelin sheath, phagocytic, role in regeneration. *can ensheath many axons, but only myelinate ONE axon*
Oligodendrocytes
Type of glial cell in the CNS that wrap axons in a myelin sheath. *Can myelinate many CNS axons*
motor neurons
What types of neurons does the anterior horn of the spinal chord contain?
pyramidal cells
found in the cerebral cortex, have a triangular cell body and *a single, long dendrite (apical dendrite)* among many smaller dendrites
basal dendrite
one of several dendrites on a pyramidal cell that extend horizontally from the cell body
synaptic end bulb
swelling at the end of an axon where neurotransmitter molecules are released onto a target cell across a synapse
axodendritic synapse
synapses between the axon endings of one neuron and the dendrites of other neurons
apical dendrite
the dendrite that extends from a pyramidal cell to the outermost surface of the cortex (blue)
intrafusal fibers
the muscle fibers found within a muscle spindle
ribosomal rosette
Cluster of ribosomes in the dendrites of neurons that *allow for local protein synthesis and play a role in memory and learning*
extrafusal fibers
Contractile skeletal muscle fibers outside of the muscle spindle. *Innervated by Alpha-motor neurons*
myelin ovoids
Degenerating myelin that precipitates during chromatolysis
ependymal cells
Non-neuronal cells that line cavities of the brain and spinal cord, circulate cerebrospinal fluid (blue)
Nissl substance
RER found in cell body and dendrites, but not axon of neurons. *Can use this to differentiate b/w dendrites and axon hillock of soma*
Golgi tendon organs
Receptors sensitive to change in tension of the muscle and the rate of that change
astrocytes
Support cells of the CNS that prevent large fluctuations in brain chemistry *Can be recognized by grey material containing GFAP (glial fibrillary acidic protein)*
axosomatic synapse
Synapse between axon and the soma of another neuron
dorsal root ganglia
Where are psuedounipolar neuron cell bodies located?
microtubules
Which filament is larger, microtubules or neurofilaments?
white matter
Whitish nervous tissue of the CNS consisting of the *myelinated axons of neurons* Dark on staining b/c myelin is stained
muscle spindle
a receptor parallel to the muscle that responds to a stretch
neuroglia
cells that support and protect neurons Include: -oligodendrocytes -astrocytes -schwann cells -satellite cells
Chromatolysis
process of a neuron regrowing its broken axon process happens in the soma increased protein synthesis + round cellular swelling = push the nuc to the side increase in nissl bodies
Meissner's corpuscles
sensitive touch receptors in the dermis (*light touch*)