internal anatomy

Question 1

What does the periphery of the spinal cord contain ?

Answer 1

white matter that contain myelinated axons and dendrites

Question 2

What is contained within the white matter?

Answer 2

gray matter which contain neuronal cell bodies and mostly unmyelinated neuronal processes

Question 3

What is centrally located in the gray matter?

Answer 3

Central canal which contains the CSF

Question 4

how is the gray matter arranged?

Answer 4

in bilaterally symmetric horns:
Dorsal horn 
ventral horn 
lateral horn 
gray commisure

Question 5

What does the dorsal horn contain?

Answer 5

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

Question 6

What does the ventral horn contain?

Answer 6

cell bodies of lower motor neurons which convey somatic motor info to skeletal muscle

Question 7

what does the lateral horn contain?

Answer 7

cell bodies of preganglonic sympathetic motor neurons only present T1-L2

Question 8

What is the gray commisure?

Answer 8

interconnects the right and left hemispheres of the spinal cord

Question 9

How is the white matter organized?

Answer 9

bilateral symmetric columns containing tracts of specific types of neuronal processes:
Dorsal white columns
spinothelamic tracts
lateral corticospinal tracts

Question 10

What are the different dorsal white columns?

Answer 10

Fasciculus gracilis -medial, lower limb sensory tract

fasciculus cuneatus - lateral, upper limb sensory tract

Question 11

Where are the dorsal white columns located?

Answer 11

posteriorly between the dorsal horns of the gray matter

Question 12

What do the dorsal white columns contain?

Answer 12

axons of the first order afferent neurons that convey fine touch proprioception from the ipsilateral side of the body wall

Question 13

Where are the spinothelamic tracts located?

Answer 13

ventrally and ventrolatteralyy around the gray horns of the gray matter

Question 14

What do the spinothelamic tracts contain?

Answer 14

axons of the second order affront neurons that convey temp, pressure , noiciception and crude touch from the contralateral side of the body.

Question 15

Where are the lateral corticospinal tracts located?

Answer 15

laterally, posterior to the spinothelamic tracts and lateral to the dorsal horns of the gray matter

Question 16

What do the lateral corticospinal tracts contain?

Answer 16

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

Question 17

What is the distribution of white matter in the spinal cord?

Answer 17

it decreases inferiorly through the spinal cord

the upper regions no longer contribute to the white matter inferiorly

Question 18

Where does the lateral horn exist?

Answer 18

only between T1-L2 levels

this is the location of the sympathetic neuronal cell bodies in the spinal cord