Overview Flashcards
All neurons have at least 1 axon and 1 or more dendrites EXCEPT 2
amacrine cells of retina
granule cells of olfactory bulb
axons are covered with myelin sheaths from supporting cells: namely
Schwann cells - PNS
Oligodendroglia - CNS
Largest of the neurohlia
stain poorly
nuclei are ovoid and centrally located
cytoplasm contain small round granules and glial filaments composed of glial fibrillary acidic protein
Astrocytes
During development, these supporting cells provide a framework which provides neuronal migration
Astrocytes (radial glia)
Type of astrocytes found primarily in the white matter, concerned with metabolite transference and the repair of damaged tissue
Fibrous astrocytes
Aka as satellite cells
in close association with neurons and may partially envelop them
located primarily in the gray matter
serve as metabolic intermediary for nerve cells
Protoplasmic astrocytes
Nuclei are round, condensed stainable (heterochromatin) nuceloplasm
cytoplasm is densely filled with mitochondria, micrtubules, ribosomes but devoid of neurofilaments
Oligodendroglia
Line the central canal of the Spinal Cord and ventricles of the brain
vary from cuboidal to columnar in shape and may possess cilia
Involved in the formation of the CSF
Ependymal Cells
These cells are mesodermal in origin
Cell bodies are small, little cytoplasm, densely staining and flat elongated nuclei
in the presence of destructive lesion, these cells enlarge and become mobile and phagocytic, thus they become macrophages, or scavenger cells
Microglia
collections of nerve cell bodies located outside the CNS
Ganglia
2 types of ganglia
Craniospinal
Autonomic
Craniospinal composed of
31 pairs pf spinal nerves
CN V, VII, VIII, IX, X
Spinal Group are what type of neurons
Vestibular and cochlear nerves are of what type
Spinal group - pseudounipolar
Vestibular and cochlear - bipolar neurons
Location of
Sympathetic Ganglia
Parasymathetic
Sympathetic - adjacent to vertebral bodies
Paraympathetic - located within the organ they innervate
type of neurons in the autonomic ganglia
multipolar
Nerve Fiber Sizes A alpha A beta A gamma A delta B C
A alpha (Ia and Ib) - 12-22 um A beta (II) - 5-12 um A gamma (II) - 2-8 um A delta (III) - 1-5 um B <3 um C (IV) 0,1 - 0.3 um
function and source of which type of Nerve Fibers
proprioception, stretch and motor to skeletal muscle fibers (extrafusal)
A alpha Ia
function and source of which type of Nerve Fibers
contractile force Golgi tendon organ
A alpha Ib
function and source of which type of Nerve Fibers
pressure, strech, touch, vibratory sense
A beta
function and source of which type of Nerve Fibers
Motor to muscle spindle (intrafusal)
A gamma
function and source of which type of Nerve Fibers
some nerve endings, serving pain, temp, touch
A delta
function and source of which type of Nerve Fibers
sympathetic preganglionic axons
B
function and source of which type of Nerve Fibers
other pain, temp, mechanical receptors, sympathetic ganglion, postganglionic axons (motor to smooth muscle and glands)
C
characeteristic proteins involved in fast anterograde trasnport and fast retrograde transport
fast anterograde trasnport - kinesin
fast retrograde transport - dynein
