PNS and Spinal Cord Flashcards Preview

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Flashcards in PNS and Spinal Cord Deck (42)
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1
Q

what is the difference b/w afferent and efferent nerve fibers

A

afferent carries info in to CNS

efferent carries info out (exit )

2
Q

which horn of the spinal nerve is responsible for motor impulses

A

anterior/ventral horn (efferent fibers)

3
Q

which horn of the spinal nerve is responsible for sensory information

A

posterior/dosral horn (afferent)

4
Q

what are the 3 wrappings around peripheral nerves

A

epinuerium, perineurium, and endoneurium

5
Q

which nerve wrapping would surround the entire nerve fascicle and is continuous with the dura mater

A

epineurium

6
Q

which nerve wrapping is continuous with the arachnoid mater

A

perineurium

7
Q

major blood vessels in the brain exist b/w what 2 nerve wrappings

A

epineurium and perineurium

8
Q

this part of a myelinated axon contains many Na channels and is involved in signal propagation down an axon

A

Nodes of Ranvier

9
Q

what is the function of myelin

A

surrounds axons and insulates them which increases conduction velocity

10
Q

what is the difference b/w the 2 types of cells that produce myelin

A

Oligodendrocytes - only in CNS and 1 cell can myelinate many axons
Schwann cells - only in PNS and 1 cell only myelinate 1 axon

11
Q

Saltatory conduction

A

depolarization jumps from node to node reknewing at each node

12
Q

amplitude of signal conduction depends on ?

A

axon thickness

13
Q

velocity of signal conduction depends on ?

A

myelination

14
Q

what is a nociceptor

A

pain receptor

15
Q

what is the general organization of a nerve receptor

A

specific receptive area, synaptic area (sends signal to CNS)

16
Q

what is a receptive field

A

ability to convey information on the location of stimulus

17
Q

T/F sensory receptors have the ability to adapt over time

A

T - adaptation occurs at receptor level but CNS can regulate receptor sensitivity

18
Q

what are the 2 types of encapsulated receptors

A

muscle spindles, and golgi tendon organs

19
Q

what do muscle spindles detect

A

detect muscle length

20
Q

what do golgi tendon organs detect

A

detect muscle tension

21
Q

what is the organization of the spinal cord segments

A

8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccyx

22
Q

all spinal nerves each innervate ____ dermatome except ?

A

1, C1

23
Q

what is the conus medullaris

A

caudal end of the spinal cord

24
Q

where are the 2 enlargements of the spinal cord ?

A

cervical (C5-T1) and lumbar (L2-S3)

25
Q

what level cross section of the spinal cord would reveal an oval shape

A

cervical transverse section

26
Q

a cross section at what level of the spinal cord would have the most gray matter

A

lumbosacral transverse section

27
Q

what is the point of communication of the spinal cords at the midline called

A

anterior white commisure

28
Q

gray matter at all transverse sections of the spinal cord is what shape

A

H-shaped

29
Q

the substantia gelatinosa is found where on the spinal cord and is responsible for what ?

A

located in the posterior/dorsal horn

area that responds to pain and temperature sensory info.

30
Q

alpha or lower motor neurons innervate muscles _____ whereas gamma motor nuerons innervate ____ ?

A
alpha = muscle fibers
gamma = muscle spindles
31
Q

what are the 2 specialized collumns that are found in the anterior horn at the cervical level

A

spinal accessory nucleus - forms accesory nerve

phrenic nucleus - forms phrenic nerve

32
Q

preganglionic sympathetic neurons are located where

A

T1-L3 in intermediate horn

33
Q

where is Clarke’s nucleus found and what is it responsible for ?

A

intermediate horn from T1-L2 and involved with proprioception of the leg

34
Q

which cross section of the spinal cord would show the least white matter

A

sacral cross section

35
Q

where would you perform a lumbar puncture and why ?

A

L4-L5 because the actual spinal cord stops at L1-L2

36
Q

how is the spinal cord attacthed to the dura mater

A

filum terminale - anchors the conus medullaris to end of dural sheath

37
Q

where are the cauda equina nerve fibers found

A

L1-S2 (from end of cord to end of dura)

38
Q

what is the function of denticulate ligaments

A

lateral anchoring of the spinal cord

39
Q

what type of reflex does not involve interneurons

A

stretch reflex

40
Q

the stretch reflex is monosynaptic, what does that mean

A

1 synapse b/w 2 neurons

41
Q

muscle tension can inhibit motor neurons, what encapsulated receptor sensed this

A

golgi tendon organ

42
Q

what is another name for the great vertebral radicular artery

A

artery of Adamkiewicz