nerve elements

Question 1

_________ neurons (aka somatosensory), _________ neurons (aka motor), and __________ nerves are the components of a peripheral nerve

Answer 1

afferent
efferent
autonomic

Question 2

PNS order of physical size

Answer 2

peripheral nerve > afferent and efferent fibers > fascicles (bundles of axons) > individual nerve fibers (aka axons)

Question 3

functional unit is the

Answer 3

axon

Question 4

________ cells surround the axon

Answer 4

schwann

Question 5

_______ ______ are around the axons and between the axon and schwann cells

Answer 5

myelin sheaths are around the axons (in myelinated nerves) and between the axon and schwann cells

Question 6

______ of _______ are interspersed among the axon at spaces that are not myelinated

Answer 6

nodes of ranvier

Question 7

these nodes, or axon intervals, have _______ gated ______ ________ that propagate the nerve conduction and are primary site for LA action

Answer 7

voltage
Na channels

Question 8

electrical impulses are conducted by localized depolarizations which transmit an electrical signal. resting membrane potential is negative _____ to _____ mV

Answer 8

-60 to -90

Question 9

_________ gated _______ channels are the primary mediator for influx of ______ which propagates depolarization

Answer 9

voltage gated Na channels
Na

Question 10

there are three states of the Na channel:

Answer 10

1. activated open
2. inactivated closed
3. rested closed

Question 11

LAs have the ability to block the channels in the ____ ____ _____ only

Answer 11

first two states only (activated open and inactivated closed)

Question 12

the inability of the nerve to fire during inactivated state, the refractory period, prevents ______ _______ of the nerve impulses

Answer 12

retrograde conduction

Question 13

nerve fibers can be _______ or __________

Answer 13

myelinated or unmyelinated

Question 14

generally, myelinated are _____ fibers, have _______ conduction, and are associated with _______ and ______ function

Answer 14

larger
faster
motor and sensory function

Question 15

unmyelinated fibers generally have _______ conduction and transmit ________, _______, and ________ impulses

Answer 15

slower
pain
temp
autonomic

Question 16

nerve fiber size is classified as ___, ____, and _____, with ______ being the largest and _______ being the smallest

Answer 16

A, B, and C
A
C

Question 17

A fibers have subgroups of _______, ________, _______, and ________ fibers, and are the most myelinated

Answer 17

alpha
beta
gamma
delta

Question 18

alpha fibers functionality includes ______ _______ and _______-

Answer 18

motor signals
proprioception

Question 19

beta fibers functionality includes ______, _______, and ______ recognition

Answer 19

motor, touch, and pressure

Question 20

gamma fibers carry ______

Answer 20

reflexes

Question 21

delta fibers transmit _______ and ________

Answer 21

pain and temp

Question 22

B fibers have less myelination and carry _______ _______

Answer 22

autonomic signals

Question 23

C fibers are smallest fibers and are unmyelinated, they carry ______ and _______ signals

Answer 23

pain and temp

Question 24

with LAs, the ________ and ______ _______ the fibers are generally harder to block

Answer 24

larger and more myelinated

Question 25

the order of blockade is generally:

Answer 25

B fibers, C fibers, A delta fibers followed by the heavily myelinated fibers

recovery from LA occurs in reverse order

Question 26

CNS communication from the body (sensory) is through the ____________ aspect of the cord

Answer 26

dorsolateral

Question 27

CNS communication to the body occurs through the __________ from the _________ aspect of the cord

Answer 27

ventral root
ventrolateral

Question 28

2 roots converge to form a spinal nerve before dividing into the ______ and _______ _____ innervating the anterior and posterior structures

Answer 28

dorsal and ventral rami

Question 29

spinal nerves are comprised of ____ pairs: ____ cervical and ____ thoracic, ____ lumbar, _____ sacral, and ____ coccygeal nerve

Answer 29

31 pairs
8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal

Question 30

the vertebral bone components have multiple _________ of which the clinician should be aware

Answer 30

projections

Question 31

_____ levels
_____ cervical, _____ thoracic, ______ lumbar _____, sacral, and _____ coccyx

Answer 31

33 levels
7 cervical
12 thoracic
5 lumbar
5 sacral
4 coccyx

Question 32

spinous processes are directed _______ at the cervical levels while _______ at the lumbar levels

Answer 32

caudad
straight

Question 33

C6 correlates with

Answer 33

cricoid cartilage

Question 34

C7 is the

Answer 34

most prominent cervical level called “vertebral prominens”

Question 35

T2 correlates with the

Answer 35

superior angle of the scapula and sternal notch

Question 36

T4 is the

Answer 36

plane of ludwig that correlates carina and angle of Louis

Question 37

T7 is the

Answer 37

inferior angle of the scapulae

Question 38

T9 is the

Answer 38

Xiphoid

Question 39

T10 correlates with the

Answer 39

umbilicus

Question 40

L4 correlates with the

Answer 40

superior iliac crest

Question 41

spinal nerves and their level of origin are not always exactly in line with the ______ _______ of the body where they provide coverage. the ______ _______ will show a different spinal nerve level than the vertebral height

Answer 41

surface landmark
dermatome chart

Question 42

brachial plexus is formed by ____-_____ between the _______ and ______ _______ muscles

Answer 42

C5-T1
anterior and middle scalene

Question 43

radial nerve forms from _____-_____. functionally operates the ______, supination of the ________, extension of the _______, abduction of the ______, and extension of ______ ______

Answer 43

C5-T1
triceps
forearm
wrist
thumb
other fingers

Question 44

median nerve forms by _______ and _______ cords and follows the track of the brachial artery lying medially to it. functionally it flexes the _________, pronates the ________, flexes the _______, flexes the ______&______, abducts the ______

Answer 44

lateral and medial cords
flexes the elbow
pronates the forearm
flexes the wrist
flexes the fingers and thumb
abducts the thumb

Question 45

ulnar nerve - formed by ____-____, follows the _____ ______ following the posterior aspect of the medial epicondyle. flexion of the _____, ______, and ____ _______, adduction of ________, adduction of ________, flexion of ______

Answer 45

C8-T1
follows the brachial artery
flexion of the wrist, ring, and small fingers
adduction of fingers
adduction of thumb
flexion of thumb

Question 46

spinal nerves travel in the intercostal spaces and to the thoracic and abdominal compartments and are called _______ ________

Answer 46

intercostal nerves

Question 47

femoral nerve develops from _____-_____

Answer 47

L2-L4

Question 48

sciatic nerve is formed from _______ (___-___) and _____ ______ ______ (___-___)

Answer 48

tibial (L4-S3)
common peroneal nerves (L4-S2)

Question 49

sciatic nerve functionally extends the _____, flexes the _____, plantar flexes ______, dorsiflexes ____ and all movement of the toes.

Answer 49

sciatic nerve functionally extends the hips, flexes the knee, plantar flexes the ankle, dorsiflexes the ankle, and all movement of toes