Lecture 3-spinal cord pt 3 Flashcards Preview

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Flashcards in Lecture 3-spinal cord pt 3 Deck (51)
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1

what does gray matter contain
what does white matter contain

-cell bodies and their dendritic processes and synaptic connections
-myelinated fibers/axons going longitudinally

2

what is a tract/fasciculus

collectoin of axons w/ a common origin, course, and termination

3

what is a funiculus/column

2 or more fasciculi

4

what does the dorsal funiculus contain?

fasciculus gracilis (all lvls)
fasciculus cuneatus (C1-T6)

5

what do the ventral funiculus contain?

the ventral white commissure

6

where is the dorsal intermediate sulcus found

midthoracic segments and above (C1-T6)
-notably absent in lumbar regions, only found where there is fasiculus cuneatus

7

which fissure/sulci is very deep?

ventral median fissure unlike the dorsal median sulcus

8

what receives dorsal roots white

dorsal lateral

9

where do ventral roots emerge white

ventral lateral

10

what does the dorsal horn gray contain

sensory

11

what does the ventral horn gray contain

motor nuclei

12

waht does the lateral horn gray contain? where is it present at?

autonomic motor
only present w/ symp pre gang cell body (T1-L3 only)

13

what is the substantia gelatinosa homologous to?

spinal trigeminal nucleus

14

where is clarke's nucleus found?

T1-L3

15

what information does substantia gelatinosa carry?

senosry in function, temperature
substance P
these are nuclei

16

where is clarke's nucleus prominent at

lower thoracic levels

17

where is clarke's nucleus located? why is it located there?

dorsal horn gray bc of its function in sensory prcoessing

18

waht does substance P act liek a cap to

dorsal horn

19

what does the ventral horn contain

cell bodies for lower motor neurons and found at all levels of the cord

20

what are the two types of lower motor neurons

alpha motor neurons: innervate extrafusal striated skeletal muscle fibers ("do work" when lifting)

gamma motor neuron: innervate intrafusal muscle fibers of muscle spinkles (keeps muscle spindle receptor sensitive to new changes in lenght)

21

what happens when alpha motor neurons are lesioned

cant contract skeletal muscle which leads to paralysis

22

why do alpha motor neurons have enormous cell bodies and dendritic trees?

bc everyone wants to influence them. there are lots of descending tracts and reflex pathways that will want to synapse on them in order to influence their final decision as to whether to "fire" to contract msucle

23

how do alpha motor neurons leave the ventral horn gray? what do they eventually merge w/ and innervate?

via ventral roots and will eventually merge into the spinal nerve and go out to the periphery to innervate skeletal muscle

24

what do alpha motor neurons that are located more medially tend to innervate

axial muscles or ones that are considered proximal like shoulder and arm

25

in the chunk of ventral horn that is located more lateral, what do those alpha motor neurons tend to innervate/

the appendicular or distal muscles like the forearm and hand (limbs)

26

where are flexor motor neurons located at in the ventral horn ?
where are extensor motor neurons located in the ventral horn?

more dorsally in the ventral horn

more ventral in the ventral horn

27

where is the intermediolateral cell column found
what do they contain

lateral horns
preganglionic sympathetic fibers

28

where does the oculosympathetics originate from? and wehre at

the ciliospinal center of budge at C8-T2

29

how are the cervical regions shaped? and why?

oval shaped and contain the largest absolute amount of white matter.
-all of the descending tracts, destined for cervial, thoracic, lumbar, and sacral have to go through the cervical region
-sensory ascending tracts starting in the sacral region go up, from lumbar and adding on thoracic, adding on cervical, etc.
SO...dorsal columns are more fully present at the cervical levls

30

why is the cord enlarged in the lower cervical and lumbosacral regions

to accommodate innervation of the arms and legs