Lecture 27 Nerves of the Upper Limb Flashcards
1
Q
What is the primary function of the brachial plexus?
A
- provides somatomotor and somatosensory innervation to the upper extremity
2
Q
Does the brachial plexus supply sympathetics?
A
- Yes
3
Q
Where does the brachial plexus arise from?
A
- cervical enlargement of spinal cord
4
Q
What forms the brachial plexus?
A
- the anterior rami of cervical spinal nerve roots C5-T1
5
Q
What is the pathway of the brachial plexus?
A
- these spinal nerve roots emerge from the intervetrebral foramina of cervical vertebrae and pass between the anterior and middle scalene muscles of the neck
6
Q
Where does the brachial plexus emerge from?
A
- the intervertebral foramina
7
Q
What muscles does the brachial plexus pass between?
A
- anterior and middle scalene muscles
8
Q
What rami is the brachial plexus comprised of?
A
- ventral
dorsal would go to back of neck
9
Q
What are the supraclavicular structures?
A
- phrenic nerve
- omohyoid
- sternocleiod mastoid
- subclavian vein (passes anterior to anterior scalene muscle)
- subclavian artery (passes with plexus between scalene muscles)
10
Q
What is a potential complication of an interscalene block?
A
- anesthesia of the diaphragm and temporary respiratory depression due to proximity of the phrenic nerve
11
Q
What are interscalene blocks used for?
A
- used for shoulder procedures bc they numb all of the spinal nerve components of shoulder
12
Q
What are interscalene blocks used for?
A
- used for shoulder procedures bc they numb all of the spinal nerve components of shoulder
- then surgeon removes adhesions of shoulder
13
Q
When do we call the subclavian artery the axillary artery?
A
- when it passes beneath clavicle and 1st rib
14
Q
Where does the axillary artery run in regards to the brachial plexus?
A
- right in the middle
15
Q
What does the neurovascular bundle travel within?
A
- axillary sheath
16
Q
What spinal nerves contribute to dermatones outside of the brachial plexus?
A
- C4-T5
17
Q
shoulder dermatone
A
- C4
18
Q
C5
A
- upper lateral arm and shoulder
19
Q
C6
A
- posteriolateral arm and lateral forearm
20
Q
C7
A
middle of forearm and hand
21
Q
C8
A
posterioromedial forearm and medial hand
22
Q
T1
A
- medial arm
23
Q
T2-T5
A
- axillary region
24
Q
What is a dermatome?
A
- area of cutaneous sensory innervation supplied by a single spinal nerve
25
Cutaneous nerve innervattion overlaps multiple _____
- dermatomes
26
What is a myotome?
- a group of muscles that receive motor innervation from a single spinal nerve
27
What myotome does the action of shoulder elevation
- C4
28
What myotome does the action of shoulder abduction and elbow flection
C5
29
What myotome does the action of elbow flexion, wrist extension
C6
30
What myotome does the action of elbow extension and wrist flexion
C7
31
What myotome does the action of thumb and finger extension
C8
32
What myotome does the action of intrinsic hand muscles
T1
33
What myotome does the action of intercostal muscles
T2
34
Do cutaneous maps have multiple nerve contributions?
- YES
35
Why is there not a 1:1 correspondence between named cutaneous nerves and dermatomes?
- because dermatomes are a single nerve innervating a single sensory part whereas cutaneous nerves are comprised of multiple nerves and can innervate multiple dermatomes
36
why is T2 spinal nerve on left significant
- refereed pain during angina and cardiac events
37
As a general rule an individual named muscle in the limbs is supplied by _____ than one spinal nerve
- more
38
What is the upper trunk of the brachial plexus that is made up of?
- C5- C6
39
What is the middle trunk of the brachial plexus made up of?
- C7
40
What is the lower trunk of the brachial plexus made up of?
- C8-T1
41
What do the anterior divisions of the brachial plexus give rise to?
- medial and lateral cord
42
What do the posterior divisions of the brachial plexus give rise to?
- posterior cord
43
What are the branches of the brachial plexus?
- axillary nerve
- musculo cutaneous nerve
- radial nerve
- median nerve
- ulnar nerve
44
What innervates the anterior compartment of the arm?
- musculocutaneous nerve
45
What innervates the posterior compartment of the arm?
- radial nerve
46
What nerve is a flexor of elbow joint?
- musculocutaneous nerve
47
What nerve is an extensor of elbow joint?
- radial nerve
48
What separates the anterior and posterior compartments?
- the medial and lateral intermuscular septa
49
What nerves are in the anterior compartments of the forearm?
- ulnar and median nerves
50
What are the nerves that are in the posterior compartment of the forearm?
- radial nerve
51
what is the shoulder region innervated by?
- nerves that come directly from the roots, trunks, or cords of the brachial plexus
52
What is the arm region innervated by?
- medial cord (cutaneous)
- musculocutaneous n (anterior)
- radial n. (posterior)
53
the forearm region is innervated by?
- a branch from the medial cord (cutaneous)
- median and ulnar nerves (anterior)
- radial n (posterior)
54
The hand receives all motor innervation from the?
- median and ulnar nerves
55
where does the hand receive sensation from?
- median
- ulnar
- radial nerves
56
What nerve does the lateral cord give off?
- lateral pectoral nerve
57
What nerves does the medial cord give off?
- medial pectoral nerve
- medial brachial cutaneous nerve
- medial antebrachial cutaneous nerve
58
What nerves does the posterior cord give off?
- upper and lower subscapular nerves
| - thoracodorsal nerve (middle subscapular nerve)
59
Do both the lateral cord and median cord contribute to the median nerve?
- Yes
60
What gives rise to the musculocutaneous nerve?
- Lateral cord
61
What gives rise to the ulnar nerve?
- medial cord
62
What gives rise to the axillary and radial nerve?
- posterior cord
63
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ROOTS
TRUNKS
DIVISIONS
CORDS
BRANCHES
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REAL TEXANS DRINK COLD BEER
64
What nerves make the upper trunk?
- C5 and C6
65
What nerves make the middle trunk?
- C7
66
What nerves make the lower trunk?
- C8 and T1
67
What nerves make up the axillary nerve?
- C5 and C6
68
What nerves make up the posterior cord?
- C5
- C6
- C7
- C8
- T1
69
What nerves make up the radial nerve?
- C5
- C6
- C7
- C8
- T1
70
What nerves make up the ulnar nerve?
- C7
- C8
- T1
71
What nerves make up the median nerve?
- C5
- C6
- C7
- C8
- T1
72
What nerve makes up the musculocutaneous nerve?
- C5
- C6
- C7
73
What makes up the lateral cord?
- C5
- C6
- C7
74
What makes up the medial cord?
- C7
- C8
- T1
75
Superior trunk injury leads to
- arm adducted
- arm will be internally (medially) rotated at the elbow
- there will be pronation
- there will be extension
(waiters tip)
76
What does an injury to the superior trunk lead to?
- weakness of axillary nerve
| - weakness of s
77
What would happen if you injured the axillary region?
- weakness when trying to push something away
- difficulty extending the wrist
- difficulty extending the fingers and opening hand
- wrist drop posture
