D
F
J
A
H
G
J
E
C
B
the gray matter is in the center of the cord and forms horns, the white matter
surrounds the perimeter and forms columns
the meninges of the spinal cord cover and protect it. the layers are in the same
order as the coverings of the brain: dura mater (outer), arachnoid (middle), and pia
mater (inner)
see table 13-2 on page 432 of text.
1. stimulus, 2. activation of sensory neuron, 3. information processing in CNS, 4.
activation of motor neuron, 5. response be effector.
posterior median sulcus
central canal
posterior root of spinal n.
posterior root ganglion
anterior root of spinal n.
gray matter
anterior white column
anterior median fissure
anterior gray horn
lateral gray horn
posterior gray horn
lateral white column
posterior white column
obturator nerve innervates the adductor muscles of the hip; this nerve is part
of the lumbar plexus attaching to the spinal cord at segments L2-L4.
anterior gray horn contains somatic motor nuclei; posterior gray horn contains
somatic and visceral sensory nuclei; lateral gray horn contains visceral motor nuc.
it could happen, if the nerve were mixed containing axons of motor neurons and
dendrites of sensory neurons; problems with the nerve could affect both.
the patellar reflex is an example of a stretch reflex; beginning with the knee bent,
the physician taps the knee which stretches the muscle group further and triggers
contraction of the group to counteract the stretch.