Download Axial vs. Appendicular Skeleton

SC.912.L.14.28
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What does the spinal cord do?
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White matter – nerve impulse conduction
Grey matter – receives and integrates
incoming and outgoing information
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Axons within the descending tracts control
the smooth muscles of internal organs and
the skeletal muscles of the arms and legs.
Neural signals follow specific pathways. In
the case of the descending tracts axons from
the brain synapse with cell bodies in the
spinal cord which then send impulses out to
the rest of the body.
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Sensory signals from the skin, extrmeties and
internal organs are carried via pahtways in
the ascending tracts.
Most these signals are relayed to the brain.
Some activate reflexes which are controlled
by interneurons in the spinal cord and are not
addressed by the brain.
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Each spinal cord segment marks where spinal
nerves emerge from the cord to connect with
specific regions of the body.
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Cervical spinal nerves (C1 to C8) control signals to
the back of the head, the neck and shoulders, the
arms and hands, and the diaphragm.
Thoracic spinal nerves (T1 to T12) control signals
to the chest muscles, some muscles of the back,
and parts of the abdomen.
Lumbar spinal nerves (L1 to L5) control signals to
the lower parts of the abdomen and the back, the
buttocks, some parts of the external genital
organs, and parts of the leg.
Sacral spinal nerves (S1 to S5) control signals to the
thighs and lower parts of the legs, the feet, most of
the external genital organs, and the area around
the anus.
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May be damaged by tumors, blood clots,
wounds, trauma, or herniated disks.
Paralysis may occur depending on the extent
of the injury.