PNS and Spinal Cord Flashcards Preview

Anatomy > PNS and Spinal Cord > Flashcards

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

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

afferent carries info in to CNS
efferent carries info out (exit )

2

which horn of the spinal nerve is responsible for motor impulses

anterior/ventral horn (efferent fibers)

3

which horn of the spinal nerve is responsible for sensory information

posterior/dosral horn (afferent)

4

what are the 3 wrappings around peripheral nerves

epinuerium, perineurium, and endoneurium

5

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

epineurium

6

which nerve wrapping is continuous with the arachnoid mater

perineurium

7

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

epineurium and perineurium

8

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

Nodes of Ranvier

9

what is the function of myelin

surrounds axons and insulates them which increases conduction velocity

10

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

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

11

Saltatory conduction

depolarization jumps from node to node reknewing at each node

12

amplitude of signal conduction depends on ?

axon thickness

13

velocity of signal conduction depends on ?

myelination

14

what is a nociceptor

pain receptor

15

what is the general organization of a nerve receptor

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

16

what is a receptive field

ability to convey information on the location of stimulus

17

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

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

18

what are the 2 types of encapsulated receptors

muscle spindles, and golgi tendon organs

19

what do muscle spindles detect

detect muscle length

20

what do golgi tendon organs detect

detect muscle tension

21

what is the organization of the spinal cord segments

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

22

all spinal nerves each innervate ____ dermatome except ?

1, C1

23

what is the conus medullaris

caudal end of the spinal cord

24

where are the 2 enlargements of the spinal cord ?

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

25

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

cervical transverse section

26

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

lumbosacral transverse section

27

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

anterior white commisure

28

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

H-shaped

29

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

located in the posterior/dorsal horn
area that responds to pain and temperature sensory info.

30

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

alpha = muscle fibers
gamma = muscle spindles

31

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

spinal accessory nucleus - forms accesory nerve
phrenic nucleus - forms phrenic nerve

32

preganglionic sympathetic neurons are located where

T1-L3 in intermediate horn

33

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

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

34

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

sacral cross section

35

where would you perform a lumbar puncture and why ?

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

36

how is the spinal cord attacthed to the dura mater

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

37

where are the cauda equina nerve fibers found

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

38

what is the function of denticulate ligaments

lateral anchoring of the spinal cord

39

what type of reflex does not involve interneurons

stretch reflex

40

the stretch reflex is monosynaptic, what does that mean

1 synapse b/w 2 neurons

41

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

golgi tendon organ

42

what is another name for the great vertebral radicular artery

artery of Adamkiewicz