Nervous Tissue Flashcards
A small gap between two nerve cells that neurotransmitters travel across
Synapse
Areas of axon covered by myelin sheath which are sites of impulse propagation and saltatory conduction
Internodes
Cytoplasmic region of myelin between the internode and node or ranvier
Paranode
Myelin sheath is discontinuous at intervals called?
Myelin node or Nodes of Ranvier
Where does myelination starts?
at the point where the axon emerges from the axon hillock
An axon enveloped by one fold of plasma membrane of neurolemma cells
Unmyelinated nerve fiber
Present only in the developing embryonic nervous system
Unipolar Neuron
Cell of cranial and spinal ganglia, it has two processes that fuse close to the cell body but separate at some distance from it
Pseudounipolar neuron
Synapses with a sensory receptor or soma from another ganglion; brings signals to the soma in the cranianiospinal ganglion
Afferent process of Pseudounipolar neuron
arises from craniospinal and extends to the dorsal horn of gray matter of spinal cord where it synapses with an interconnector neuron
Efferent process of Pseudounipolar neuron
has two processes that originate at opposite poles of the soma
Bipolar neuron
has many processes that arise from oval, pyramidal or stellate soma; it occurs in motor nuclei in the gray matter of the brain and spinal cord
Multipolar neuron
Connective tissue cell of the nervous system
Gliocyte or glial cell or neuroglial cell
Provide structural support to the CNS, store glycogen and release glucose
astrocyte
Have a long, thin, sparsely branched processes located in white matter
fibrous astrocyte
-Have numerous short, thick, highly branched processes
-located in gray matter
protoplasmic astrocyte
Tall and epitheloid in nature – look like epithelium but not possess a basement membrane
ependymal cells
is a mass of villi that originate from the tela choroidea and form a fuzzy tuft of epithelium that extends into the brain vesicles
choroid plexus
Kinociliated cells that line the brain ventricles and central canal of spinal cord
ependymal cells
Closely associated with neurons and blood vessels in the brain and spinal cord
oligodendrocytes
microglial cells are derived from?
mesoderm
Oval or spindle-shaped cells with scanty cytoplasm and round nucleus located at the expanded middle part of the cells
amphicytes or satellite cells or capsule cells
Produce myelin sheath of myelinated nerve fibers in the PNS
neurolemmocytes
When neurons lose the organ they innervate, they undergo degeneration and get replaced by what macrogliocyte?
astrocyte
a nervous area with a high amount of cell processes
neuropil
functions of extracellular matrix in the nervous system
cell movement
axonal movement
path finding
formation and function of synapses