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*)