spinal
cord origin is the neural tube in the embryo's.
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location :
the spinal
cord lie in the canal vertebral .
from the foramen
magnum to upper border of L2 vertebral.
Function:
which conducts sensory and motor
nerve impulses to and from the brain.
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Structure:
Spinal cord
composed by:
1-nervous
tissue .
2-support
cells .
terminating
fibrous called the filum terminate.
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CNS
contains two matter :
1-white matter-the tractus & myelinated
axons and contain the anterior ,posterior, lateral funiculus & white column).
2-gray matter -all nervous
cell bodies and axons and contain the anterior(motor),posterior(sensory),lateral(autonomic)
horn& gray column.
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the spinal nerve is the
collection of :
1-ventral (anterior) root .( motor
–skeletal muscles tissue –rootlet neuron).
2-posterior (dorsal) root .( is
sensory – fascicular neurons).
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the horns of the spinal cord are:
1-dorsal horn.
2-ventral horn.
3-laterl horn.
composition of the dorsal horn are:-
1-spongy substance .
2-substantia gelatinosa.
3-nucleus proper (located in the center of the
horn its conducting way are ventral spinocerebellar ,spinothalamic).
4- nucleus thoracic(its conducting way is back
spinocerebellar).
composition of the lateral horn :two nucleus:
A-medial
intermediate nucleus.
B-lateral
intermediate nucleus.
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the CNS protected by 3 layers called meninges(connective
tissue):
1-dura mater.
2-arachnoid ( are mesenchyme origin).
3-pia mater (are mesenchyme origin).
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tracts - functionally related bundles
of axons in the white matter .
The
tract is divided into:
spinocerebellar tract—set of axonal
fibers originating in spinal cord and terminates in the cerebellum.
Clarke's column (column of Clarke, dorsal nucleus, posterior thoracic nucleus) is
a group of multipolar neurons found in
Lamina VII, also known as the intermediate zone, of the spinal cord.
efferent is motor and the afferent is the sensory.
neuropil is the
meshwork of axonal ,dendrite , glial processes associated with the gray matter .
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nucleus functionally related groups
of nerve cell bodies in the gray matter (cluster or group of neuronal cell bodies
+fibers +neuroglia).
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spinal ganglia located on running dorsal root
of spinal cord (pseudounipolar neurons ).
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mantle gliocytes neurons of
spinal cord are surrounded by the layer of neuroglial cells .
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ganglia is the aggregation of cell
bodies of neurons located outside the CNS (there are the sensory and autonomic
ganglia).
spinal ganglia is a nodule
on a dorsal root that contains cell bodies of neurons in afferent spinal nerves.
vegetative ganglion—it has
multipolar neurons surrounding by nervous fibers and glyal cells and its
nervous fiber do not have middle localization.
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The fasciculus cuneatus is a bundle of nerves in the spinal cord which
primarily transmits information from the arms. It is part of the posterior
column-medial lemniscus pathway.
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blood
brain barrier endothelial cells of CNS capillaries prevent the free
passage of selective blood –borne substances into the neural tissue .
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the conducting way formed by axons of fascicular neurons of spinal cord .
communicates with the
brain, by means of
ascending and
descending pathways that
form tracts in spinal
white matter.
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Spinal Nuclei recognizable clusters of cells are identified as nuclei. The advantage
is that distinct nuclei are generally detectable, the disadvantage is that the
numerous neurons outside of distinct nuclei are not included.
Link :
الرئيسية 
موضوع: spinal cord from sami abu saaluk to group 5 
السبت سبتمبر 24, 2011 9:13 am