General concepts of the nervous system Flashcards
gray matter
nerve cell bodies lie within this
looks like an H
CELLULAR
divided into horns
white matter
interconnecting fiber tract systems
FIBER nature
funculi
anterior (ascending/descending motor tracks, pain and temperature tracks that ascend)
lateral (same as anterior)
posterior (sensory info from all areas of the body below the head taken up to areas of the brain)
afferent
sensory
toward CNS
efferent
motor
from the CNS
how many pairs of spinal nerves
31
how many thoracic nerves
12
how many cervical pairs
8
how many lumbar nerves
5
how many sacral
5
how many coccygeal nerves
1
NOTE: a ganglion exists on the dorsal root, which contains what?
the cells bodies of all the afferent sensory fibers, except for vagal afferents, below the level of the head
where does the first spinal nerve exit?
between the skull and CV1
how are spinal nerves numbered and where do they exit?
exit intervertebral foramina EXCEPT for in the cervical region
mixed nerve
motor and sensory formed at the junction of a dorsal and ventral root
dorsal root ganglion
is a nodule on a dorsal root of the spine that contains cell bodies of nerve cells (neurons) that carry signals from sensory organs toward the appropriate integration center.
nucleus-group of cell bodies found within the central nervous system
ganglion- nerve cell bodies located outside the CNS
dermatone
the unilateral area of skin innervated by the sensory fibers of a single spinal nerve
central nervous system
brain and spinal cord
PNS
12 cranial nerves and 31 pairs of spinal nerves