Flashcards in internal anatomy Deck (18)
What does the periphery of the spinal cord contain ?
white matter that contain myelinated axons and dendrites
What is contained within the white matter?
gray matter which contain neuronal cell bodies and mostly unmyelinated neuronal processes
What is centrally located in the gray matter?
Central canal which contains the CSF
how is the gray matter arranged?
in bilaterally symmetric horns:
What does the dorsal horn contain?
cell bodies of second body afferent neurons that relay sensory info
processes of first order sensory neurons crying pain and temperature(cell bodies are located in the dorsal root ganglion) synapse on order neurons here
What does the ventral horn contain?
cell bodies of lower motor neurons which convey somatic motor info to skeletal muscle
what does the lateral horn contain?
cell bodies of preganglonic sympathetic motor neurons only present T1-L2
What is the gray commisure?
interconnects the right and left hemispheres of the spinal cord
How is the white matter organized?
bilateral symmetric columns containing tracts of specific types of neuronal processes:
Dorsal white columns
lateral corticospinal tracts
What are the different dorsal white columns?
Fasciculus gracilis -medial, lower limb sensory tract
fasciculus cuneatus - lateral, upper limb sensory tract
Where are the dorsal white columns located?
posteriorly between the dorsal horns of the gray matter
What do the dorsal white columns contain?
axons of the first order afferent neurons that convey fine touch proprioception from the ipsilateral side of the body wall
Where are the spinothelamic tracts located?
ventrally and ventrolatteralyy around the gray horns of the gray matter
What do the spinothelamic tracts contain?
axons of the second order affront neurons that convey temp, pressure , noiciception and crude touch from the contralateral side of the body.
Where are the lateral corticospinal tracts located?
laterally, posterior to the spinothelamic tracts and lateral to the dorsal horns of the gray matter
What do the lateral corticospinal tracts contain?
axons of efferent upper motor neurons for the ipsilateral side of the body
the cell bodies arise from the from which these fibers arise lie within the brainstem on the contralateral side
What is the distribution of white matter in the spinal cord?
it decreases inferiorly through the spinal cord
the upper regions no longer contribute to the white matter inferiorly