Exam 3: Unit V Brachial Plexus Flashcards
(101 cards)
1
Q
What fibers form the Brachial plexus?
A
anterior primary rami of C5 through T1
may also receive some fibers from C4 and/or T2
2
Q
In general, what does the brachial plexus supply?
A
upper extremities
3
Q
How does the brachial plexus travel?
A
travels laterally over fib 1, into the axilla–> travels medial to lateral
4
Q
Describe the “layout” of the brachial plexus
A
Roots combine into–> trunk, which divide into–> divisions, which combine to form –> cords, which divide into –> terminal nerves (branches)
“Rugby Team Drinks Cold Tequila/Beer”
5
Q
What does each root of the brachial plexus receive from the sympathetic trunk?
A
gray ramus communicans
6
Q
How do the roots of the brachial plexus pass?
A
b/w anterior and middle scalene muscles into the posterior triangle
posterior and superior to subclavian artery
7
Q
What forms the scalene triangle?
A
anterior scalene, middle scalene, and first rib
8
Q
In the brachial plexus, roots of what levels form the:
- superior trunk
- middle trunk
- inferior trunk
A
- C5, C6
- C7
- C8, T1
9
Q
What do the trunks (superior, middle, and inferior) pass over and what do they enter?
A
pass over rib 1 into the axilla
10
Q
What does each trunk of the brachial plexus split into?
A
anterior division and posterior division
11
Q
What will the anterior divisions of the brachial plexus supply? what will the posterior divisions supply?
A
anterior–> ant. compartments or arm and forearm
posterior–> posterior compartments of arm and forearm
12
Q
What are the cords of the brachial plexus named in relationship to? What are the names of the cords?
A
the axillary artery
Lateral, Medial, Posterior cords
13
Q
What is the lateral cord formed by? What fibers does it contain?
A
anterior divisions of superior and middle trunks
- contains C5,C6,C7
(lies lateral to second part of axillary artery)
14
Q
What forms the medial cord? What fibers does it contain?
A
formed by anterior division of the inferior trunk
- contains fibers C8 to T1
(lies medial to second part of axillary artery)
15
Q
What is the posterior cord formed by? What fibers does it contain?
A
formed by union of posterior divisions of all three trunks (sup. middle, inf.)
- contains C5,C6,C7,C8,T1
(lies posterior to second part of axillary artery)
16
Q
How many and what are the names of the nerves formed from roots of the brachial plexus?
A
two
- Dorsal Scapular Nerve (C5)
- Long Thoracic Nerve (C5,C6,C7)
17
Q
What fibers does the Dorsal Scapular Nerve contain?
A
C5 ONLY
18
Q
What muscles does the Dorsal Scapular Nerve supply?
A
- Levator scapula (also fibers from C3, C4)
- Rhomboid major
- Rhomboid minor
(C5 fibers)
19
Q
What fibers does the Long Thoracic Nerve have? What muscles does it supply?
A
C5,C6,C7
Serratus anterior muscle
20
Q
How many and what are the names of the nerve branching off of the trunks of the brachial plexus?
A
two
- Suprascapular Nerve ( C5,C6)
- Nerve to the subclavius (C5,C6)
21
Q
What muscles does the Suprascapular Nerve supply?
A
(C5,C6)
- supraspinatus
- infraspinatus
(2 rotator cuff muscles)
22
Q
What muscle does the Nerve to the Subclavius supply? What nerve fibers?
A
C5 and C6
- subclavius
23
Q
How many and what are the names of the nerves branching off of the lateral cord of the brachial plexus?
A
two
- Lateral pectoral nerve (C5,C6,C7)
- Musculocutaneous Nerve (C5,C6,C7)
24
Q
What does the Lateral Pectoral nerve supply?
A
Pectoralis Major (also gets innervation from Media Pectoral Nerve)
25
What are the two terminal branches of the lateral cord?
```
musculocutaneous nerve
median nerve (partial contribution from medial cord too)
```
26
What muscles does the musculocutaneous nerve supply?
- coracobrachialis
- biceps brachii (long and short heads)
- brachialis
(muscles of anterior arm)
27
What muscles does the musculocutaneous nerve pierce?
pierces belly of coracobrachialis
28
After the musculocutaneous nerve supplies the muscles in the anterior arm, how does it continue? What does it become?
b/q the biceps brachii and brachialis into the forearm to become the Lateral Cutaneous Nerve of the Forearm
29
What does the Lateral Cutaneous Nerve of the Forearm supply?
skin over lateral aspect of the forearm, NOT the hand
30
How many and what are the names of the nerves branching off the medial cord of the brachial plexus?
(5)
1. Medial Pectoral nerve
2. Medial cutaneous nerve of the arm
3. Medial cutaneous nerve of the forearm
4. Ulnar nerve
5. Median Nerve (gets partial contribution from medial cord)
31
What fibers does the Medial Pectoral Nerve contain? What muscles does it supply?
C8 and T1
- Pectoralis major (gets supplied by Lateral Pectoral Nerve too)
- Pectoralis minor
32
What nerves supply the Pectoralis major?
Lateral pectoral nerve and medial pectoral nerve
33
What fibers does the Medial Cutaneous nerve of the arm contain? What does it supply?
C8 and T1
- skin of medial arm b/w axilla and elbow
--> receives some fibers from T2 through a communication with intercostobrachial nerve
34
Besides receiving fibers from C8 and T1, what else does the Medial Cutaneous Nerve of the arm receive some fibers from?
from T2 through a communication with intercostobrachial nerve
35
What fibers does the Medial Cutaneous nerve of the forearm contain? What does it supply?
C8 and T1
| - skin over biceps brachnii and skin over anterior and medial aspects of forearm proximal to the wrist
36
Describe how the Medial Cutaneous nerve oft he forearm leaves the medial cord?
leaves just distal to the medial cutaneous nerve of the arm
37
What are the two terminal branches of the medial cord?
```
Ulnar Nerve
Median Nerve (also from lateral cord)
```
38
T/F. The Ulnar nerve gives off branches in the arm before entering into the forearm.
False-- it does NOT give off branches in the arm
39
What fibers does the Ulnar nerve contain?
C8, T1, and sometimes C7
40
Describe how the Ulnar nerve travels.
travels medial to the brachial artery, in the medial bicipital sulcus (gives off NO branches in the arm)
-->
crosses over elbow on posterior side of medial epicondyle in sulcus for ulnar nerve
--> into forearm b/w 2 heads of flexor carpi ulnaris
(innervated 2 mucles in forearm and 2 sensory branches)
--> travels deep to flexor carpi ulnaris to the wrist
--> passes SUPERFICIAL to flexor retinaculum and divides into Superficial and Deep branches
41
What nerve is easily palpated on the posterior side of the elbow and referred to as the "funny bone"?
Ulnar nerve
42
What muscles does the Ulnar nerve innervate in the forearm?
two
- Flexor Carpi Ulnaris
- Flexor digitorium profundus (medial half)
43
What sensory branches does the Ulnar nerve give off in the forearm? What do they supply?
two
- Dorsal Branch of the Ulnar Nerve--> skin on ulnar side of posterior hand
- Palmar Branch of Ulnar Nerve--> skin over hypothenar eminence
44
Describe how the Ulnar nerve travels to the wrist?
travels deep to flexor carpi ulnaris to the wrist--> passes superficial** to the flexor retinaculum and divides into two branches
45
How branches does the Ulnar nerve divide into after is passes superficial to the flexor retinaculum?
Superficial--> which divides into 3 terminal branches and supplies skin
Deep--> curves toward thenar eminence and supplies muscles
46
What does the Superficial branch of the Ulnar nerve given off in the hand supply?
divides into 3 terminal branches (proper palmar branches)--> supply palmar aspect of little finger and medial half of ring finger
47
What does the Deep branch of the Ulnar nerve in the hand supply?
- Abductor digiti minimi
- Flexor digiti minimi brevis
- Opponens digiti minimi
- Adductor pollicis
- Deep head of Flexor pollicis brevis
- All interossei (dorsal and palmar)
- 3 and 4 Lumbricals
(all muscles in hand except Abductor pollicus brevis, opponens pollicus, and 1 and 2 lumbricals)
48
If someone has Claw hand or Ape hand, what nerve is affected?
Ulnar nerve
-- distal interphalangeal joints flex and proximal don't
or
4th and 5th digits flexed
49
What cords form the Median nerve?
lateral and medial cords
50
What fibers does the Median nerve contain?
C6, C7, C8, T1
51
How does the Median nerve travel throught the arm? What branches does it give off here?
in the medial bicipital sulcus; NO branches given off in arm
52
How does the Median nerve cross the elbow?
on anterior side and then passes b/w two heads of pronator teres and enters forearm
53
What muscles does the Median nerve innervate in the forearm?
7
- Pronator teres
- Flexor carpi radialis
- Palmaris longus
- Flexor digitorum superficialis
then via Anterior interosseous nerve of the forearm:
- Pronator quadratus
- flexor pollicis longus
- lateral bellies of flexor digitorium profundus
54
What branch does the Median nerve give off in the forearm that supplies three muscles? What are those muscles?
Anterior Interosseous nerve of the forearm
- Pronator quadratus
- flexor pollicis longus
- lateral bellies of flexor digitorium profundus
55
What branch does the Median nerve give off in the distal third of the forearm? What does it supply?
Palmar Branch of the Median Nerve; supplies:
| - skin of thenar eminence, lateral wrist, and palm
56
How does the Median nerve enter the wrist? How does it divide?
it passes THROUGH the carpal tunnel and divides into three Common Palmar Digital Nerves
57
What do the three Common Palmar Digital Nerves (branches of the Median nerve) supply?
- first two lumbricals (1 and 2)
Branches of the First Common Palmar Digital Nerve supply:
- Abductor pollicis brevis
- Flexor pollicis bravis (superficial head)
- Opponens pollicles
58
How does the branch of the Median nerve, Common Palmar Digital Nerves, split?
each splits into two Proper Palmar Digital Nerves
| ---are SENSORY only
59
What do the Proper Palmar Digital Nerves supply? (splits from the Common Palmar Digital Nerves off Median Nerve)
SENSORY ONLY
- skin over anterior part of lateral three and 1/2 digits
- skin over posterior part of lateral two and a 1/2 digits
60
What else does the Median nerve supply besides the muscles and skin?
- periosteum
- elbow, radiocarpal, and midcarpal joints
- usually communicates with ulnar nerve at the wrist
61
What would be a good way to test the Median nerve and why?
have patient try and pronate b/c ONLY the median nerve supplies the muscles of pronation ( Pronator teres and Pronator quadratus)
62
What nerve may be affected due to carpal tunnel syndrome?
Median nerve--> fingers may tingle where sensory distribution is for median nerve
63
What nerve is the characteristic issue called the " Hand of oath/benediction" ass. with?
Median nerve
| -- 4th and 5th digits can flex and cannot flex other digits
64
How many branches are off the posterior cord of the brachial plexus and what are their names?
five
- Superior Subscapular nerve
- Thoracodorsal nerve
- Inferior Subscapular nerve
- Axillary nerve
- Radial nerve
65
What fibers does the Superior subscapular nerve contain? What does it supply?
C5 and C6
| subscapularis (also gets innervation from inf. subscapular N.)--> rotator cuff muscle
66
What fibers does the Thoracodorsal nerve contain? What does it supply?
C6,C7,C8
| travels along posterior axillary wall to supply the latissimus dorsi
67
What fibers does the Inferior subscapular nerve contain? What does it supply?
C5 and C6
- subscapularis (also gets innervation from sup. subscap. N.)--> rotator cuff muscle
- teres major
68
What fibers does the Axillary nerve carry? How does it travel?
C5 and C6
| runs in axilla and travels posteriorly around surgical neck of humerus
69
At the same level that the branch to the Teres minor is given off from the Axillary nerve, what other branch is given off? How do the remaining fibers travel?
the sensory branch--> Superior Lateral Cutaneous Nerve of the Arm
remaining fibers travel to the deltoid
70
How does the Superior Lateral Cutaneous Nerve of the arm supply?
(branch off Axillary nerve)
| - skin over lateral shoulder and upper arm
71
What type of fibers does the Radial nerve contain?
C5, C6, C7, C8, and ~T1
72
In general, what muscles does the Radial nerve supply?
muscles in the posterior compartment of the arm and forearm (NO MUSCLES IN THE HAND)
73
Describe the path of the Radial nerve.
from the medial bicipital sulcus it spirals around to posterior of humerus ----> travels b/w brachialis and brachioradialis--> and enters forearm anterior to elbow
74
What muscles does the Radial nerve pass b/w as it enters into the forearm?
b/w brachialis and brachioradialis
75
What muscles does the Radial nerve pass b/w as it enters into the forearm?
b/w brachialis and brachioradialis
76
What are the three cutaneous branches the Radial Nerve gives off in the arm? Describe where they branch off.
1. Posterior cutaneous nerve of the arm (upper arm)
2. Inferior lateral cutaneous nerve of the arm (radial middle arm)
3. Posterior cutaneous nerve of the forearm (given off in upper arm
77
The muscular branches the Radial nerve gives off in the arm will supply what muscles?
- triceps brachii (all 3 heads)
- anconeus (via branch off the branch to medial head of triceps)
- brachialis (in combination with musculocutaneous)
78
What does the Posterior cutaneous nerve of the arm supply?
(branch of Radial Nerve that branches off in upper arm)
| - skin on posterior side of upper arm
79
What does the Inferior lateral cutaneous nerve of the arm supply?
(branch of Radial Nerve that branches off in middle arm)
| - overlaps with Post. Cut. N. of the Arm (skin on post. side of upper arm)
80
What does the Posterior cutaneous nerve of the forearm supply?
(branch of Radial nerve give off in upper arm)
| - narrow area of skin on lateral side of the posterior forearm
81
What do the branches supply that the Radial nerve give off at the level of the lateral epicondyle?
- Brachioradialis
| - Extensor carpi radialis longus
82
Once the Radial nerve passes into the forearm, what does it do?
divides into a superficial branch and a deep branch at the level of the radial head
83
What is the path of the Superficial Branch of the Radial nerve?
follows brachioradialis to distal third of forearm--> then travels b/w brachioradialis and radius to posterior surface of hand--> and gives rise to dorsal digitial nerves
--> also gives off "communicating branch with ulnar nerve"
84
What does the Superficial Branch of the Radial nerve given off at the level of the radial head supply?
sensory supply to:
- Radial side of posterior hand
- Extensor side of thumb
- Extensor side of proximal phalanges of digits 2 and 3
- Lateral half of extensor side of the ring finger
--> also gives off "communicating branch with ulnar nerve"
85
What other branch does the Superfical Branch of the Radial nerve also give off that is not for the sensory supply?
the communicating branch with the ulnar nerve
86
Describe the path of the Deep branch of the Radial nerve.
penetrates the supinator muscle--> gives off series of branches to supply posterior forearm--> terminates as the "Posterior Interosseous nerve"--> which supplies 9 muscles
87
What muscles does the Deep branch of the Radial nerve penetrate?
supinator muscle
88
What does the Deep Branch of the Radial Nerve terminate as?
Posterior interosseous nerve--> supplies 9 muscles
89
What muscles does the terminating branch, Posterior interosseous nerve, of the Deep branch of the radial nerve supply?
9
- Extensor carpi radialis brevis
- Supinator
- Extensor digitorum
- Extensor digiti minimi
- Extensor capri ulnaris
- Abductor pollicis longus (snuff box)
- Extensor pollicis brevis (snuff box)
- Extensor pollicis longus (snuff box)
- Extensor indicis
90
What does the Radial nerve also send fibers do besides the muscles and skin it supplies?
articular branches to the shoulder and wrist
91
If a patient came in with wrist drop, what nerve are you thinking is involved?
Radial nerve, b/c cannot extend the wrist and the Radial nerve supplies muscles that contribute to wrist extension
Varies:
--> may not be able to lift it
--> may not be able to resist force you apply
92
What nerve are we testing if we test the Triceps and brachioradialis reflexes?
Radial nerve
93
If there is Supraclavicular damage to the brachial plexus what may occur?
Erb-Duchenne = internally rotated shoulder and flexed wrist
94
Damage to what roots does Erb-Duchenne involve?
- C5, C6 roots; superior most part of brachial plexus
95
What will we see atrophy of in someone with Erb-Duchenne? (nerves and then following muscles)
- Suprascapular N----> supraspinatus and infraspinatus
- Musculocutaneous N--> biceps brachii and brachialis
- Axillary N --> deltoid
96
What is the MC cause of Erb-Duchenne?
birth trauma
97
If there is infraclavicular damage to the brachial plexus, what may occur?
Klumpke's Palsy ( or Dejerine-Klumpke) = see claw hand/ape hand
98
What roots are damaged in Klumpke's Palsy?
C8, T1; medial cord
99
What will we see atrophy in someone with Klumpke's Palsy?
- Ulnar N --> hypothenar muscles, flexor carpi ulnaris, medial 1/2 of flexor digitorum profundus, interossei
- Median N--> thenar muscles
100
We know Klumpke's Palsy can result from damage to C8 and T1. What type of fibers does T1 carry? If someone has damage to C8/T1, and we know Klumpke's Palsy can result, what else can result?
carries preganglionic sympathetic fibers
may disrupt sym. to head--> cause Horner's Syndrome
101
What are two signs of Horner's Syndrome?
- ptosis (droopy eyelid)
| - miosis (dry eye)
