spinal cord segmental organization Flashcards
Where is the posterior median sulcus?
posterior/dorsal surface
Where is the posterior lateral sulcus?
dorsal root entry zone (sensory)
Where isq the anterior median fissure?
anterior/ventral midline
Where is the anterior lateral sulcus?
exit anterior (motor) roots
What is the dorsal (posterior) root ganglion?
give rise to central and peripheral nerve fibers.
Where is the central canal located?
In the gray commissure
Where can we find lateral gray horn?
in thoracic & upper lumbar segments of the cord
Into what is the white matter divided?
columns or funiculi
What are the columns of the spinla cord?
dorsal (posterior) column
lateral column
ventral (anterior) column
identify
cervical
identifyq
thoracic
identify
lumbar
identify
sacral
What are the type of neurons in the gray matter?
Local interneurons
Commissural neurons
Propriospinal neurons
What are local interneurons?
axons remain on ipsilateral (same
side) gray matter within a cord
segment
What are commissural neurons?
axons cross midline to
terminate in contralateral
(opposite side) gray matter
What are propriospinal neurons?
axons project rostrally (superiorly) or caudally (inferiorly) in surrounding
white matter for several segments before terminating in gray matter
What are interneurons?
-Majority of spinal neurons
-Receive information from primary sensory afferents, dorsal horn neurons, motor neurons, & descending pathways
-Integrate segmental activity that
controls spinal sensory processing &
motor and autonomic outputs
-May have excitatory or inhibitory effects on other spinal neurons
(excitatory neurons are glutamatergic)
(inhibitory neurons are GABAergic or glycenergic)
What are second order sensory neurons?
Projection neurons:
neurons which are glutamatergic and project axons from the dorsal and
intermediate gray horn to the thalamus, brainstem or cerebellum
What are cholinergic (acetylcholine) motor neurons?
Projection neurons:
located in the ventral horn and project
to skeletal muscle
What are cholinergic autonomic preganglionic neurons?
located in the intermediate gray matter and project to autonomic ganglia.
Where is the dorsomarginal nucleus found?
all cord levels in lamina I
What type of sensations does dorsomarginal nucleus has?
light touch (non-specific), pain and temperature sensations
What does dorsomarginal nucleus contain?
contains somas of 2nd-order sensory neurons that project to the thalamus