Lecture 9 Musculoskeletal Growth/Injury and Repair- Nerve

Question 1

What are axons coated with

Answer 1

Endoneurium

Question 2

What is another name for nerve bundles

Answer 2

Fascicles

Question 3

What are nerve bundles covered with

Answer 3

Perineurium

Question 4

Fascicles are grouped together to form_____

Answer 4

A nerve

Question 5

What is the covering of a nerve called

Answer 5

Epineurium

Question 6

What is the function of Group IA and IB fibres

Answer 6

15 microns
Large motor axons
Muscle stretch and tension sensory axons

Question 7

What is the function of Group II afferents

Answer 7

12-14 microns

Touch, pressure, vibration and joint position sensory axons

Question 8

What is the function of Ag fibres

Answer 8

8-10 microns

Gamma efferent motor axons

Question 9

What is the function of Group III afferents

Answer 9

10-15 microns

Sharp pain, very light touch & temperature sensation

Question 10

What is the function of group B fibres

Answer 10

3-10 microns

Sympathetic pregranglionic motor axons

Question 11

What is the function of C Group IV afferents

Answer 11

<1.5 microns

Dull, aching, burning pain and temperature sensation

Question 12

Name classical compression injuries

Answer 12

Carpal tunnel syndrome
Sciatica
Morton’s neuroma

Question 13

What is neurapraxia

Answer 13

• Nerve in continuity- all the way down to the axon
• Stretched (8% will damage microcirculation) or bruised
• Reversible conduction block

Question 14

What is axonotmesis

Answer 14

Endoneurium intact but disruption of axons

Question 15

What is neurotmesis

Answer 15

Complete nerve division
Laceration or avulsion
No recovery unless direct suturing or grafting

Question 16

What are classed as closed nerve injuries

Answer 16

Neuopraxis

Axonotmesis

Question 17

What are classed as open injuries

Answer 17

Nerve division

Neurotmetic injuries

Question 18

What are the clinical features of nerve damage

Answer 18

Dysesthesia
Paresis
Dry skin
Diminished or absent reflexes

Question 19

What are the 2 types of nerve repair

Answer 19

Direct repair

Nerve grafting

Question 20

What is the rule of three for traumatic peripheral nerve injury

Answer 20

• Immediate surgery within 3 days for clean and sharp injuries
• Early surgery within 3 weeks for blunt/contusion injuries
• Delayed surgery performed 3 months after injury, for closed injuries

Question 21

How is the strength affected in LMN lesion

Answer 21

Decreased

Question 22

How is the tone affected in LMN lesion

Answer 22

Decreased

Question 23

How is the deep tendon relfexes affected in LMN lesion

Answer 23

Decreased

Question 24

How is clonus affected in LMN lesion

Answer 24

Absent

Question 25

Would you see Babinski's sign in LMN lesion

Answer 25

No

Question 26

Is atrophy present in LMN lesion

Answer 26

Yes