Lecture 3 - Spinal Nerves: Part 1 Flashcards
1
Q
Cervicogenic headaches due to the greater occipital nerve impingement are very common. Is the greater occipital nerve dorsal or ventral ramus of which spinal nerve? Where is the dermatome of the greater occipital nerve?
A
Dorsal ramus of C2, posterior ½ scalp, most common cause of HA.
2
Q
How many pairs of spinal nerves are there?
A
31
3
Q
How many cervical spinal nerves are there?
A
8
4
Q
Where is the 1st spinal nerve?
A
occiput and C1 vertebra, only motor
5
Q
Where are the 2-8 spinal nerves?
A
under each cervical vertebra (+1 rule)
6
Q
How many thoracic spinal nerves are there?
A
12
7
Q
How many lumbar spinal nerves are there?
A
5
8
Q
How many sacral spinal nerves are there?
A
5
9
Q
How many coccygeal spinal nerves are there?
A
1
10
Q
What is the endoneurium?
A
continuous component from pia mater wrapping single axon
11
Q
What is the perineurium?
A
continuous component from arachnoid mater wrapping bundles of axons
12
Q
What is the epineurium?
A
continuous component from meningeal dura wrapping bundles fascicles
13
Q
How do we test the endo-, peri, and epi-neurium?
A
SLR and slump test
14
Q
What supplies the spinal nerve?
A
the plexus of arterioles around the peripheral nerves
15
Q
What are some ischemia mechanisms of the spinal nerves?
A
- double crush theory (2+ spine = problems)
- DM peripheral neuropathy (different mechanism for ischemia, high blood sugars can cross-link arteries)
16
Q
What is neuropraxia?
A
compression injury with intact axons
17
Q
What happens with intact endoneurium?
A
a good chance to recover but slow
18
Q
What is axonotmesis?
A
tear of axons
19
Q
What is neurotmesis?
A
tear of whole fascicle or nerve
20
Q
What happens with neurotmesis?
A
- disrupted endo-peri and/or epineurium: poor chance of recovery
21
Q
What does the medial branch of the dorsal ramus in the thoracic trunk innervate?
A
- dura mater, vertebral disc, facet joints, intrinsic back muscles, and skin
22
Q
What is RFA?
A
Radiofrequency ablation - burn nerve out to decrease radiculopathy
23
Q
What does the lateral branch of the dorsal ramus do for the thoracic spinal nerves?
A
intrinsic back muscles mainly and skin slightly
24
Q
What are the two branches of the ventral ramus of the trunk?
A
cutaneous and muscular branch
25
What are the two cutaneous branches (for throacic/trunk) of the ventral ramus?
- lateral cutaneous branch: anterior and posterior branch
- Anterior cutaneous branch: lateral and medial branch
26
What does the muscular branch (for thoraci/trunk spinal n.) of the ventral ramus innervate?
intercostals, serratus posterior and abdominal wall muscles
27
What are the myotomes of the ASIA scale?
C5-T1, L2-S1
- major limb muscles 5 each of UE and LE
28
What are dermatomes?
segmental distribution of nerve innervation, crude touch and sharp pain by a delta
29
What are dermatomes of the trunk?
ventral and dorsal rami of spinal nerves
30
What are dermatomes of neck and extremities?
peripheral nerves from the plexus, formed by ventral rami
31
What are the LMN sizes for SR, FR and FF?
* SR: small
* FR: medium
* FF: large
32
What is the motor unit size for SR, FR and FF?
*SR: small
* FR: medium
* FF: Large
33
What is the concentration of mitochondria in the SR, FR and FF fibers?
* SR: high
* FR: medium
* FF: low
34
What are the concentration of glycogen in for SR, FR and FF?
* SR: low
* FR: medium
* FF: high
35
What is the contraction time for SR, FR and FF?
* SR: hours
* FR: ~1 hour
* FF: ~ 1 minute
36
What is the function of SR muscle fibers?
- fine motor/ endurance
37
What is the function of FR muscle fibers?
- gross motor/power
38
What in the function of FF fibers?
- gross motor/power
39
What are the muscles for SR?
- posture/fine motor: multifidi/semispinalis/rotators/soleus
40
What are the muscles for FR?
- in-between: erector spinae
41
What are the muscles for FF?
- strenuous work: quad/gastroc
42
What rami forms the cervical plexus?
ventral rami
43
What is the greater occipital nerve formed from?
dorsal ramus, C2
44
What are the components of the cervical plexus?
- lesser occipital nerve
- great auricular nerve (mandibular angle)
- transverse cervical nerve
- supraclavicular nerve
- C1 to geniohypoid
- ansa cervicalis
- phrenic nerve
45
Where does the supraclavicular nerve exit?
proximal 1/3 of posterior SCM (nerve point)
46
C2, C3 is important why?
innervates posterior cranial fossa dura mater = OA refers as HA above this level
47
What are the components of the ansa cervicalis?
- superior root: C1 through hypoglossal nerve
- Inferior root (C2-C3)
48
What are the target muscles of the ansa cervicalis?
- infrahyoid neck muscles except the thyrohyoid
49
What are the nerve roots of the phrenic nerve?
- C3-C5
50
What are the nerve roots of the ventral rami?
C5, C6, C7, C8, T1
51
What are the roots of the superior trunk?
C5/C6
52
What are the roots of the middle trunk?
C7
53
What are the roots of the inferior trunk?
C8/T1
54
What is the inferior trunk seperated by?
the 1st rib
55
What happens if the 1st rib is depressed?
radiculopathy of the medial arm/FA
56
What can happen with the cervical rib compressing C8?
ulnar nerve distribution nerve
57
What does each trunk give out?
anterior/posterior divisions
58
What do divisions form?
cords
59
What is the lateral cord formed from?
anterior division of superior/middle trunks
60
What is the medial cord formed from?
anterior division of inferior trunk
61
What is the posterior cord formed from?
all posterior divisions
62
What does the cord give out?
terminal branches
63
What does the dorsal scapular nerve innervate and what are its roots?
- levator scapular and rhomboids
C4 and C5
64
What does the long thoracic nerve innervate and what are its roots?
- seratus anterior
- C5, C6, and C7
65
What does the suprascapular nerve innervate and what are its roots?
Supra and infraspinatus
- C5 and C6
66
What does the nerve to subclavius innervate and what are its roots?
subclavius
- C5 and C6
67
What does the lateral pectoral nerve innervate? what are its roots?
pec major
- C5-T1
68
What are the roots of the lateral cord?
C5, C6, C7
69
What are some of the nerves in the lateral cord?
- lateral pectoral nerve
- musculocutaneous
- branch to medial nerve
70
What happens that is unique with the lateral pectoral nerve?
- bridge between lateral and medial cord so nerve roots are C5-T1
71
What does the musculocutaneous nerve innervate?
- coracobrachialis/biceps brachii (C5/C6)
- Brachialis (C5/C6) from musculocucucutaneous nerve, C7 from radial nerve
- Lateral antebrachial cutaneous nerve: lateral forearm cutaneous innervation
72
What are the nerve roots for the branch to median nerve?
C5-C7
73
What are the nerve roots for the medial cord?
C8 and T1
74
What does the medial pectoral nerve innervate?
pec minor and major (3 heads, C5-T1, lateral pectoral is major also)
75
What are the nerves from the medial cord?
- Medial pectoral nerve
- medial brachial cutaneous cutaneous cutaneous nerve
- medial antebrachial cutaneous nerve
- ulnar nerve
- branch to the median nerve
76
What are the forearm muscles innervated by the ulnar nerve?
- flexor carpi ulnaris
- ulnar side .5 flexor digitorium profundus
77
What are the hand muscles innervated by the ulnar nerve?
* Palmaris brevis: distal attachment to skin
* Ulnar side 2 lumbricals
* Ulnar head of flexor pollicis brevis
* Interossei/adductor pollicis
* Hypothenar eminence muscles
* Abductor digiti minimi
* Flexor digiti minimi
* Opponens digiti minimi
78
What does the cutaneous branch of the ulnar nerve innervate?
Dorsal and palmar side 1.5 digits
79
What are the forearm muscle innervated by the median nerve?
* Pronator teres
* Flexor carpi radialis
* Palmaris longus
* Flexor digitorum superficialis
* Flexor pollicis longus
* Radial ½ flexor digitorum profundus
* Pronator quadratus
80
What is layer 1 of the forearm innervated by the median nerve?
* Pronator teres
* Flexor carpi radialis
* Palmaris longus
81
What is layer 2 of the forearm innervated by the median nerve?
* Flexor digitorum superficialis
82
What is layer 3 of the forearm innervated by the median nerve?
* Flexor pollicis longus
* Radial ½ flexor digitorum profundus
* Pronator quadratus
83
What are the hand muscles innervated by the median nerve?
Thenar eminence
* Abductor pollicis brevis
* Flexor pollicis brevis (radial head)
* Opponens pollicis
- radial size 2 lumbricals
84
What are the cutaneous branch of the median nerve?
- Radial palmar side 3.5 fingers and dorsal DIP
* Radial thenar eminence by superficial radial nerve
85
A patient complains of pain down to the medial scapular border along the lateral neck. Which nerve is impinged? Which nerve root problems can result in the same signs and symptoms?
Dorsal scapular nerve: C4 and C5, levator scapulae, rhomboids
86
If the medial cord is injured, which nerves will be compromised?
Medial pectoral nerve
Medial brachial cutaneous nerve
Medial antebrachial cutaneous nerve
Ulnar nerve
Root to form median nerve
