Exam Six Flashcards
(236 cards)
1
Q
What is the purpose of the clavicle?
A
serves as the only bony attachment of the upper limb to the thorax
2
Q
Name 5 major structures on the clavicle
A
acromial end, sternal end, shaft, conoid tubercle, impression for costoclavicular ligament
3
Q
The scapula serves as a bridge for what two bones?
A
clavicle and humerus
4
Q
What is the purpose of the suprascapular notch on the scapula?
A
for suprascapular artery and nerve - the superior transverse ligament of the scapula covers the notch, the artery is above and the nerve is below
5
Q
Name 12 major structures of the scapula
A
- glenoid cavity/fossa
- supraglenoid and infraglenoid tubercles
- suprascapular notch
- neck
- spine
- acromion
- coracoid process
- superior and inferior angles
- lateral and medial borders
- subscapular fossa
- infraspinous fossa
- supraspinous fossa
6
Q
Name 13 major structures of the humerus
A
- head
- anatomical neck
- surgical neck
- greater tuberosity
- lesser tuberosity
- intertubercular groove/sulcus
- deltoid tuberosity
- radial groove
- lateral and media epicondyle
- capitulum
- trochlea
- coronoid fossa
- olecranon fossa
7
Q
The pectoral girdle involves movement at how many synovial joints?
A
three
8
Q
What three bones make up the pectoral girdle joints?
A
humerus, scapula, clavicle
9
Q
Describe how one can move the upper limb with or without movement of the scapula
A
- first 30 degrees of elevation of upper limb can occur WITHOUT movement of the scapula
- the act of fully elevating the arm requires abduction at the glenohumeral joint and scapular rotation such that when the arm is fully elevated (180 degrees of abduction), 120 degrees occurs at the glenohumeral joint and 60 degrees occurs from scapular rotation
10
Q
Name the 3 joints that make up the shoulder
A
sternoclavicular, acromioclavicular, glenohumeral
11
Q
Two main bones of the pectoral girdle and the bone that connects the pectoral girdle to the arm/upper limb
A
pectoral girdle: scapula and clavicle
connecting bone: humerus
12
Q
What kind of joint is the sternoclavicular joint? What is one significant fact about it as far as its articulation purpose?
A
Saddle joint in terms of morphology, ball and socket joint in terms of function
*only bony articulation between the upper limb and the thorax
13
Q
Tell me what type of joint the acromioclavicular joint is and what 3 ligaments are found within it. Also tell me what you call a dislocation at this joint.
A
- plane synovial joint
- acromioclavicular ligament, coracoclavicular ligament, coracoacromial ligament
- dislocation known as shoulder separation
14
Q
Name the 2 ligaments found in the sternoclavicular joint
A
both called sternoclavicular ligaments
15
Q
Describe what happens in a shoulder separation injury
A
- clavicle separates from scapula
- severity varies
- complete rupture of all 3 ligaments > no longer able to keep the bones connected > upper limb pulls down and away from the joint, the muscles on the clavicle pull it up and away > creates a gap
16
Q
Tell me what kind of joint the glenohumeral joint is and tell me what four major ligaments hold it together
A
- ball and socket joint»_space; main joint of the shoulder
- glenohumoral ligament, coracohumeral ligament, transverse humeral ligament, coracoacromial ligament
17
Q
Describe the glenohumeral joint and its capsule/cavity
A
- joint capsule comprises a series of stabilizing ligaments originating a the glenoid labrum
- joint capsule stretches medially from the margin of the glenoid fossa to the anatomical neck of the humerus
- capsule is weakest inferiorly b/c it is not reinforced by the coracoacromial arch or rotator cuff muscles at this point
18
Q
What is the glenoid labrum and what is its purpose?
A
- fibrocartilaginous ring surrounding the glenoid cavitiy
- expands the actual joint surface but holds only 1/3 of the humeral head
19
Q
What is the most common direction of humeral dislocation and what do we call it?
A
inferiorly at the capsule - called anterior dislocation
20
Q
What provides the most support and stability for the glenohumeral joint?
A
rotator cuff muscles b/c the ligaments are weak
21
Q
Function of the 3 (inferior, middle, superior) glenohumeral ligaments
A
provide lots of mobility
22
Q
describe the function of the transverse humeral ligament of the glenohumeral joint
A
holds the long tendon of the biceps brachii within the bicipital groove
23
Q
describe the function of the Coracoacromial ligament of the glenohumeral joint
A
reinforces superior border of glenohumeral joint preventing superior dislocation
24
Q
What are the 5 primary movements of the scapula?
A
elevation/depression
retraction/protraction
rotation
25
Name the 6 primary movements of the glenohumeral joint
medial and lateral rotation
abduction/adduction
flexion/extension
26
name the 4 anterior axio-appendicular muscles and tell me what exactly they are in terms of their function
- extrinsic muscles attaching the upper limb to the thorax
| - pec major, pec minor, subclavius, serratus anterior
27
Pectoralis major - O, I, A, N
Proximal attachment - clavicular head: anterior medial shaft of the clavicle
sternal head: anterior surface of sternum
Distal - lateral lip of intertubercular groove of the humerus
Nerve: lateral and medial pectoral
Actions: adducts, medially rotates, flexes humerus, can extend the humerus from a flexed/elevated position
28
pectoralis minor - O, I, A, N
proximal: 3rd -5th ribs
distal: medial border of the coracoid process (scapula)
nerve: medial pectoral
actions: stabilizes the scapula; elevates ribs (accessory muscle of respiration)
29
subclavius - O, I, A, N
proximal: junction of the first rib and manubrium
distal: inferior center of the clavicle
nerve: nerve to subclavius
actions: anchor and depress the clavicle
30
serratus anterior - O, I, A, N
proximal: lateral parts of ribs 1-8
distal: medial anterior border of the scapula
nerve: long thoracic (superficial to muscle)
actions: protracts, rotates, stabilizes scapula on thorax
31
Damage to the long thoracic nerve causes what condition?
results in winged scapula >>> makes it hard to raise the arm
32
Name the 5 posterior axio-appendicular muscles
trapezius, levator scapulae, rhomboid major, rhomboid minor, latissimus dorsi
33
Trapezius - O, I, A, N
proximal: occipital bone, spinous processes of C1-T12
distal: lateral third of clavicle, acromion, superior border of scapular spine
nerve: accessory (CN XI)
actions: elevates, retracts, rotates, depresses scapula
34
Levator scapulae - O, I, A, N
proximal: transverse processes C1-C4
distal: superior angle of scapula
nerve: dorsal scapular
action: elevates scapula
35
Rhomboid major - O, I, A, N
proximal: spinous process T1-T4
distal: medial border of scapula below scapular spine
nerve: dorsal scapular
actions: retract and elevate scapula
36
Rhomboid minor - O, I, A, N
proximal: spinous process of c6-C7
distal: medial border of scapula above scapular spine
nerve: dorsal scapular
actions: retract and elevate scapula
37
Latissiumus dorsi - O, I, A, N
proximal: spinous processes of T7-12, thoracolumbar fascia, iliac crest
distal: floor of the intertubercular groove on humerus
nerve: thoracodorsal
actions: adducts, extends, medially rotates humerus
38
Name the 6 scapulohumeral muscles, which are intrinsic muscles connecting the scapula to the humerus (specify which 4 make up the rotator cuff)
```
deltoid
teres major
suprapinatus*
infraspinatus*
teres minor*
subscapularis*
```
39
Deltoid - O, I, A, N
proximal: lateral third of clavicle, acromion, scapular pine
distal: deltoid tuberosity of humerus
nerve: axillary
actions: anterior part flexes and medially rotates arm, middle part abducts arm, posterior part extends and laterally rotates the arm
40
teres major - O, I, A, N
proximal: posterior surface of inferior angle of scapula
distal: medial lip of the intertubercular groove of the humerus (attaches next to lat attachment)
nerve: lower subscapular
actions: adduction and medial rotation of arm (assists the lat)
41
The 4 rotator cuff muscles function how? (in general terms)
tonic contraction of these muscles allows for more stability in the shoulder
42
supraspinatus* - O, I, A, N
proximal: supraspinatus fossa of scapula
distal: superior aspect of greater tubercle of the humerus
nerve: suprascapular
actions: initiates abduction, stabilization of glenohumeral joint
43
What happens if you damage your supraspinatus muscle?
you have a hard time getting your arm abducted up to 15 degrees
44
infraspinatus - O, I, A, N
proximal: infraspinatus fossa of the scapula
distal: greater tubercle of the humerus
nerve: suprascapular
actions: LATERAL rotation, stabilization of glenohumeral joint
45
teres minor - O, I, A, N
proximal: lateral border of scapula
distal: greater tubercle of humerus
nerve: axillary
actions: LATERAL rotation, stabilization of glenohumeral joint
46
subscapularis - O, I, A, N
proximal: subscapular fossa
distal: LESSER tubercle of humerus
nerve: upper and lower subscapular
actions: medial rotation, stabilization of glenohumeral joint
47
The subclavian artery gives off what major trunk? and what two arteries that usually come off of that?
thyrocervical trunk
- dorsal scapular artery (can be a branch of transverse cervical)
- suprascapular artery (or could be off subclavian directly)
48
Tell me where the axillary artery originates and how many parts make it up
- as subclavian passes under the clavicle it changes name to axillary
- three parts defined by their position relative to pec minor and named based on how many arteries originate from them
49
Name the artery given off by the first part of the axillary artery and where that part is located
- located proximal to pec minor
| - gives off superior thoracic artery
50
Name the 2 major arteries that come off the second part of the axillary artery and tell me where that's located
- deep (posterior) to pec minor
- thoracoacromial trunk (acromial, pectoral, clavicular, deltoid branches)
- lateral thoracic artery
51
Name the 3 major arteries that come off the third part of the axillary artery and tell me where it's located
- distal to pec minor
- anterior circumflex humeral artery
- posterior circumflex humeral artery
- subscapular artery (circumflex scapular artery, thoracodorsal artery)
52
outline the scapular anastomoses
subclavian > thyrocervical trunk > transverse cervical > dorsal scapular > thoracodorsal > subscapular > axillary
53
outline the humeral anastomosis
anterior circumflex humeral > posterior circumflex humeral
occurs at the surgical neck of the humerus
54
describe the deep veins of the upper arm
generally follow the arteries and are so named
- referred to as "venae comitantes" (accompanying veins)
55
name the 3 major superficial veins of the arm
cephalic (lateral) - drains into axillary vein, travels in deltopectoral groove
basilic (medial) - drains into axillary vein, passes through basilic hiatus
median cubital - connects basilic and cephalic veins in the cubital fossa
56
What is thoracic outlet syndrome? Tell me what nerve structure is normally involved
- constriction of narrow area between first rib, clavicle, and scalene muscles which can compress neurovascular structures that pass through it (brachial plexus, subclavian artery and vein)
- brachial plexus is most commonly involved (C8 and T1 roots) which causes numbness and tingling
- compression of subclavian vasculature is less common, but usually involves impediment of venous drainage rather than arterial blockage which causes edema and swelling
57
Tell me the symptoms of thoracic outlet syndrome
pain, numbness, muscle weakness (brachial plexus), edema (subclavian vein), muscle fatigue and cold skin (subclavian artery)
58
Name one of the common causes of thoracic outlet syndrome and typical clinical presentation
- presence of cervical ribs (present in 1-2% of population)
- usually asymptomatic
- may compress the subclavian vasculature and/or brachial plexus leading to TOS
59
Name and describe the 5 groups of axillary lymph nodes of the upper arm as to what they drain and where they drain it to
1. humeral - lateral wall of the axillary fossa medial and posterior to axillary vein
2. subscapular - posterior wall of axillary fossa along posterior axillary fold and subscapular blood vessels
3. pectoral - medial wall of axilla, surrounding lateral thoracic vein and inferior border of pec minor
4. central - deep to pectoralis minor
5. apical - at apex of axillary fossa long medial side of axillary vein and 1st part of axillary artery
60
Describe the lymphatic drainage of the basilic vein
enters cubital nodes >> humeral axillary nodes
61
which lymph nodes drain the cephalic vein?
apical axillary nodes
62
Which lymph nodes drain most of the lymph from breast tissues?
axillary nodes drain 75% of lymph from breast tissue and are clinically important in staging of breast cancer
63
we divide the axillary lymph nodes into three levels for clinical reasons, in relation to the pec minor - describe their location
level 1 - lateral to pec minor
level 2 - deep to pec minor
level 3 - medial to pec minor
64
describe the five year survival rate decreases with increasing levels of metastasis - tell me the percentages for each level of axillary nodes
level 1 - 65%
level 2 - 31%
level 3 - 0%
65
Name the 2 major spaces to know in the upper arm region
quadrangular space and triangular space
66
Describe what major structure lies in the triangular space of the upper arm, as well as the lateral, superior, and inferior borders of it
- contains the scapular circumflex artery
- lateral - long head of triceps
- superior - teres minor
- inferior - teres major
67
Tell me what two important structures lie in the quadrangular space and tell me what structures make up its four borders
- contains axillary nerve and posterior humeral circumflex artery
lateral - humerus (surgical neck)
medial - long head of triceps brachii
superior - teres minor
inferior - teres major
68
Describe what happens when the surgical neck of the humerus is fractured
- causes damage to the contents of the quadrangular space, including the axillary nerve and posterior humeral circumflex artery
- severance of the axillary nerve leads to paralysis and eventually atrophy of the deltoid (and teres minor)
69
what is the brachial plexus? How is it clinically useful when it comes to injury?
- network of lower cervical and upper thoracic ventral rami (C5-8, T1) that provide motor and cutaneous innervation to the upper limb
- motor and cutaneous deficits resulting from injury to the upper limb at various levels can be used to diagnose what specific nerves are damaged in order to anticipate progression of symptoms and inform treatment >> understanding the structure of the brachial plexus can help determine the location of an injury according to the manifestation of symptoms
70
If sensory and motor deficits follow a dermatomal and myotomal pattern, injuries are generally found where and due to what?
generally due to injuries to the roots or trunks of the brachial plexus as a result of trauma to the neck
71
Deficits that follow the distribution of peripheral nerves are generally due to injuries where and due to what?
generally due to injuries of the terminal branches of the brachial plexus as a result of trauma to the upper limb
72
describe the dermatome locations of the upper arm
- invade upper limb in a preaxial-postaxial sequence (C5-T1) where preaxial side is lateral (thumb) and postaxial side is medial (digit five)
- there is substantial overlap of dermatomes, however, there are specific autonomous regions of non-overlapping areas where nerve root functinonality can be used for neurological testing
73
What is a dermatome?
area of skin innervated by a specific nerve root
74
There are 5 nerve root levels at which dermatome sensory testing can be checked in a preaxial-postaxial pattern along the limb - name what you test at each level
```
C5 - shoulder
C6 - tip of thumb
C7 - too variable to test
C8 - tip of fifth digit
T1 - medial forearm at cubital region (elbow)
```
75
What is a myotome?
set of muscles innervated by a specific nerve root
76
Describe the myotome patterns of the upper limb
- myotomes invade upper limb in a proximal to distal sequence (C5-T1)
- associated with specific movements
77
Tell me which nerve roots innervate the shoulder, and which nerve roots innervate the intrinsic muscles of the hand
Shoulder = C5-C6
Intrinsic muscles of the hands = C8-T1
78
Tell me the actions provided by each of the nerve roots of the myotomes of the shoulder and the intrinsic muscles of the hands
C5 - abduction of shoulder, flexion of the elbow
C6 - extension of wrist
C7 - flexion of wrist, extension of fingers
C7-8 - extension of the elbow
C8 - flexion of fingers
T1 - abduction/adduction of fingers
79
Describe what a muscle reflex of a myotome is and how one would test each one (there are 3)
stretch response generally involving a direct loop between a sensory nerve synapsing with the affiliated motor nerve at the spinal cord level
- C5 biceps reflex
- C6 brachioradialis reflex
- C7 triceps reflex
80
How does one go about peripheral nerve testing in the upper limb?
- each peripheral nerve is made up of multiple roots, so the area of innervation will be composed of overlapping dermatomes - specific areas to test for function of peripheral nerves
81
There are five areas of the upper limb which can be tested for peripheral nerve function - name them and where to test
axillary - lateral aspect of deltoid
musculocutaneous - (via lateral antebrachial cutaneous nerve) lateral forearm
radial - (via superficial branch) dorsum of webbing between thumb and index finger
ulnar - medial tip of fifth digit
82
How is the brachial plexus divided?
Roots > trunks > divisions > cords > branch
83
What are the levels of the roots of the brachial plexus?
C5-T1 >> all VENTRAL rami (all mixed)
84
tell me what two levels of the spinal cord form the upper trunk (superior) and what level of the spinal cord forms the middle trunk and what two levels form the lower trunk (inferior) of the brachial plexus
upper trunk - C5 and C6
middle trunk - C7
lower trunk - C8 and T1
85
all three trunks divide into what two things and what is the clinical importance of this?
they divide into anterior and posterior divisions
- they correlate directly to innervation of anterior (flexor) and posterior (extensor) comparmetns
86
the posterior divisions of the brachial plexus unite to form what?
posterior cord
87
the anterior divisions of the upper and middle trunks (C5-7) unite to form what?
lateral cord
88
the anterior division of lower trunk (C8-T1) forms what?
medial cord
89
The 3 cords of the brachial plexus are named in relation to what?
relationship with axillary artery
medial cord - medial to it
lateral cord - lateral to it
posterior cord - posterior to it
90
What are the two terminal branches of the posterior cord of the brachial plexus
axillary and radial nerves
91
the medial and lateral cords both send a contribution to form what nerve?
median
92
the terminal branch of the lateral cord is what nerve?
musculocutaneous nerve
93
the terminal branch of the medial cord is what nerve?
ulnar nerve
94
Tell me the levels from which the roots of the brachial plexus originate and what two nerves come directly off the roots (as well as their levels)
ventral rami from C5-T1
dorsal scapular nerve C5
long thoracic nerve C5-7
95
tell me what the levels of the three trunks of the brachial plexus are and what to nerves come directly off the upper trunk
upper (superior) trunk C5-6
- - suprascapular nerve C5-6
- -nerve to subclavius C5-6
middle trunk C7
lower (inferior) trunk C8-T1
96
Are there any nerve branches coming directly off of the two divisions of the trunk? What are the divisions made from?
no direct branches - each trunk splits into anterior and posterior divisions
97
Name the 3 cords of the brachial plexus and tell me the spinal levels for each
lateral C5-7
medial C8-T1
posterior C5-8
98
the lateral cord (C5-7) is formed from anterior divisions of upper and middle trunks - what nerve does it give off directly?
lateral pectoral nerve C5-7
99
The medial cord (C8-T1) is made from the anterior division of the lower trunk - tell me what 3 nerves come directly off of it
medial pectoral C8-T1
medial brachial cutaneous nerve C8-T1
medial antebrachial cutaneous nerve C8-T1
100
the posterior cord (C5-8) is made from the posterior divisions of each of all trunks - tell me what 3 nerves come directly off of it
upper subscapular nerve C5-6
thoracodorsal nerve C6-8
(middle subscapular)
lower subscapular nerve C5-6
101
name the two peripheral nerves that come form the posterior cord as well as their levels
Axillary nerve C5-6 - motor to deltoid and teres minor, cutaneous to lateral arm
radial nerve C5-8 - motor to posterior arm and forearm, half of brachialis, cutaneous to dorsolateral hand and posterior forearm
102
tell me which peripheral nerve comes off the lateral cord
musculocutaneous C5-7: motor to anterior arm, cutaneous to lateral forearm via lateral antebrachial cutaneous nerve
103
tell me which peripheral nerve comes off the medial cord
ulnar nerve C8-T1: motor to flexor carpi ulnaris and half of flexor digitorum profundus, all intrinsic hand muscles (Except thenar muscles, lateral 2 lumbricals), cutaneous to medial palm, and medial 1 1/2 digits
104
tell me which peripheral nerve comes off both medial and lateral cords together
median nerve C6-T1: center of the M, motor to anterior forearm (Except flexor carpi ulnaris and 1/2 flexor digitorum profundus), thenar muscles, lateral 2 lumbricals, cutaneous to lateral palm, lateral 3 1/2 digits
105
Tell me about the compartments of the upper limb, as well as their innervation (hint - there are 2 compartments)
anterior compartment innervated by anterior division
posterior compartment innervated by posterior division
divided into compartments by intramuscular septa from deep fascia
106
Tell me where the lesion occurs in Erb Duchenne Palsy and what the impact of such a lesion is
- lesion at C5-6 roots (upper plexus)
- impacts the anterior and posterior divisions of upper trunk, especially the axillary, musculocutaneous and suprascapular nerves - other peripheral nerves with upper trunk contribution will be impacted
107
Tell me the symptoms of Erb Duchenne Palsy
paralysis of abductors and lateral rotators of shoulder (loss of suprascapular and axillary nerves)
paralysis of elbow flexors and forearm supinators (loss of musculocutaneous nerve)
108
Describe the clinical appearance of Erb Duchenne Palsy
- waiter's tip hand
- loss and wasting of deltoid muscle, arms hang at side
- internal rotation of arm
- pronation at forearm (loss of biceps)
- sensory loss at shoulder and lateral arm and forearm (loss of C5-6 dermatomes)
- shoulder adducted C5, elbow extended C5, wrist flexed C6
109
Describe the kind of lesion that occurs with Klumpke paralysis, what this type of syndrome is called, the impact of it, and what symptoms are caused by the lesion
- strap hanger's syndrome
- lesion at C8-T1 roots (lower plexus injury)
- impact: lower trunk, loss of ulnar nerve and weakness in median nerve
- symptoms: loss to intrinsic muscles of hand with weakness/loss to the extrinsic hand flexors, especially those innervated by the ulnar nerve
110
Describe the clinical appearance of Klumpke paralysis, also called claw hand and strap hanger's syndrome
- loss and weakness of ulnar forearm flexors, pronators, and all intrinsic hand muscles >> hyperextension of mcp jonits due to loss of flexors C, radial deviation of wrist due to loss of flexor carpi ulnaris
- muscle wasting, especially flexor carpi ulnaris, ulnar half of flexor digitorum profundus, and all intrinsic hand muscles
- arm supination and wrist extension (from tonus of extensors and supinators)
- hand in full claw position (due to function of long flexors innervated by the median nerve, tonus of extensors, and loss of lumbricals which result in flexion at the IP joints, but extension at the MCP joint)
- sensory loss to medial forearm and hand (C8-T1 dermatomes)
111
Klumpke paralysis can disrupt the rami communicantes from T1 to the sympathetic chain resulting in horner syndrome - what are the 3 major issues caused by this syndrome?
miosis - pupil constriction due to unopposed parasympathetics
ptosis - drooping eyelid due to loss of superior tarsal muscle (innervated by sympathetics)
anhydrosis - lack of sweat on affected side
112
What side of the arm is the ulna on? What about the radius?
ulna is pinky side, lateral in anatomical position
radius is thumb side, medial in anatomical position
113
Name 7 major structures of the ulna
```
olecranon process
coronoid process
ulnar tuberosity
shaft
head (distal)
styloid process (distal)
interosseous crest
```
114
Name 6 major structures of the radius
```
head (proximal)
neck (proximal)
radial tuberosity
shaft
styloid process (distal)
interosseous crest
```
115
What 3 smaller joints make up the elbow joint as a whole?
humero-ulnar
humero-radial
proximal radio-ulnar
116
Describe the humero-ulnar joint in terms of what type of joint it is, what 3 ligaments are found there, and what movements are permitted at the joint
- hinge joint that allows flexion/extension
| - anterior, posterior and transverse (oblique) ulnar collateral ligaments
117
What is the easiest way to injure the humero-ulnar joint?
forceful, repetitive throwing
118
describe the humero-radial joint in terms of what type of joint it is, what major ligament is found there, and what movements are permitted at the joint
- ball and socket morphologically, but hinge joint functionally that allows flexion/extension
- radial collateral ligament
119
describe the proximal radio-ulnar joint in terms of what type of joint it is, what ligament helps stabilize it, and what movements are permitted at the joint
- pivot joint that allows the rotation associated with pronation and supination
- annular ligament: ties head of radius to ulna, restricting motion at the humero-radial joint to flexion/extension and dictating uniaxial rotation at the proximal radio-ulnar joint
120
What is a Colle's fracture? Tell me how it happens, who tends to do it, and what one sees clinically (5)
- fracture of the distal radius often accompanied by avulsion of the ulnar styloid
- most common forearm fracture
- usually occurs in people over age 50, esp. women
- consequence of falling on an outstretched hand
- dorsal displacement of distal fractured portion of radius results in "dinner fork" deformity seen in xray
121
Describe the mechanism and consequence of a fracture of the ulnar shaft
- usually as a result of direct trauma to the ulna
- usually not as serious as radius fractures b/c it doesn't bear as much weight
- if not properly set ,may form pseudoarthritis where remodeling of each end of the fracture and development of cartilage between them may result in a more mobile joint
122
Describe how one might posteriorly dislocate their elbow and what some of the consequences of that would be
- displace ulnar and radius posteriorly, often accompanied by avulsion of the coronoid process
- occurs when excessive force is applied to fully extended elbow or when falling forward on a flexed elbow
- medial ligaments may still be intact, pulling the ulna out of position while other ligaments are damaged
- can impact ulnar nerve because the ulna is pulled toward the medial epicondyle
123
What happens if one injures the ulnar collateral ligament?
- happens in throwing athletes who experience repetitive hyperabduction and then stretch or tear the ulnar collateral ligament
- surgical repair typically uses palmaris longus or plantaris tendon
124
What is nurse maid's elbow? How does it happen?
- radial head dislocation: radial head is pulled partially (subluxation) or completely (dislocation) out of the annular ligament
- usually due to a sudden pull upward on extended forearm
- very common in young children
125
Describe the myofascial compartments of the upper limb (2)
deep to superficial fascia, deep fascia surrounds each of the muscles, defining inter-muscular septa that divide the upper limb into distinct anterior and posterior compartments
- arm and forearm
126
Describe the "arm" compartment as far as which septa create its divisions, what the general function of the anterior compartment of it is, and what nerve is responsible for it
- divided by medial and lateral intermuscular septa
| - anterior compartment for flexion and supination, innervated by musculocutaneous nerve
127
Describe the "forearm" compartment as far as which septa create its divisions, what the general function is for the anterior compartment of it, and what nerves innervate it
- divided by the medial and lateral intermuscular septa as well as the interosseous membrane between the radius and ulna
- anterior compartment functions: flexion, abduction, adduction, pronation of wrist
- anterior compartment innervation: ulnar and median nerves (from anterior divisions)
128
biceps brachii - O, I, A, N
proximal - long head from supraglenoid tubercle of scapula, short head from tip of coracoid process
distal - radial tuberosity via bicipital aponeurosis
actions - supinates** and flexes forearm, assists in flexion at glenohumeral joint, resists dislocation
nerve - musculocutaneous
129
brachialis - O, I, A, N
**most effective flexor of elbow**
proximal - distal half of anterior humerus
distal - coronoid process and ulnar tuberosity
actions - flex forearm/elbow
nerve- musculocutaneous AND radial
130
coracobrachialis - O, I, A, N
proximal - tip of coracoid process of scapula
distal - middle third of medial surface of humerus
actions - flexion, adduction, resists dislocation at glenohumeral joint (at shoulder)
nerve - musculocutaneous
131
name the 3 muscles of the anterior arm
biceps brachii, brachialis, coracobrachilias
132
what nerve goes through the coracobrachialis?
musculocutaneous
133
pronator teres - O, I, A, N
proximal - humeral head (superficial) from medial epicondyle of humerus, ulnar head (deep) from proximal ulna
distal - lateral midshaft of radius
action - pronate forearm
nerve - median
134
palmaris longus - O, I, A, N
proximal - medial epicondyle of humerus
distal - palmar aponeurosis
action- flexion of wrist, tense palmar aponeurosis
nerve - median
135
flexor carpi radialis
proximal - medial epicondyle of humerus
distal - palmar base of metacarpal 2
action - flex and abduct (radial deviation) of wrist
nerve - median
136
flexor carpi ulnaris
proximal - medial epicondyle of humerus, proximal radius
distal - hook of hamate, pisiform, palmar base of metacarpal 5
action - flex and adduct (ulnar deviation) of wrist
nerve - ulnar
137
flexor digitorum superficialis
proximal - medial epicondyle of humerus, proximal radius
distal - base of intermediate phalanges of digits 2-5
action - flex proximal interphalangeal joint, metacarpophalangeal joint, wrist
nerve - median
138
flexor digitorum profundus
proximal - ulnar shaft, interosseous membrane
distal - base of distal phalanx of digits 2-5
action - flex distal interphalangeal joint (DIP)**, PIP, MCP, wrist
nerve - lateral half digits 2/3 is anterior interosseus nerve off median, medial half digits 4/5 is ulnar nerve
139
flexor pollicis longus
proximal - radial shaft, interosseous membrane
distal - base of distal phalanx of digit 1
action - flex 1st carpometacarpal, MCP, IP, wrist joints
nerve - anterior interosseous nerve
140
pronator quadratus - O, I, A, N
proximal - medial aspect of distal ulna
distal - lateral aspect of distal radius
action - pronate forearm
nerve - anterior interosseous
141
Name the 5 major branches of the brachial artery, which is so named once the axillary artery passes the inferior border of the teres major
```
profunda brachii
superior ulnar collateral
inferior ulnar collateral
ulnar
radial
```
142
name the 2 major arterial branches that come off the profunda brachii artery
middle collateral artery (posterior)
| radial collateral artery (termination posteriorly off middle collateral)
143
describe the path of the ulnar artery and tell me the 3 major branches that come off of it
split off from brachial in cubital fossa (usually)
anterior ulnar recurrent artery
posterior ulnar recurrent atery
common interosseous artery
144
the ulnar artery gives off the common interosseous artery - this artery provides 2 more direct branches. what are they?
anterior interosseous - perforating branches from here to posterior compartment of forearm
posterior interosseous - gives off a recurrent interosseous
145
the radial artery has one major branch - what is it?
radial recurrent artery
146
outline the 4 major anastomosis paths of the forearm/arm
profunda brachii >> radial collateral >> radial recurrent >> radial
brachial > superior ulnar collateral > posterior ulnar recurrent >ulnar
brachial > inferior ulnar collateral > anterior ulnar recurrent > ulnar
profunda brachii > middle collateral > recurrent interosseous > common interosseous > ulnar
147
the cubital fossa contains 3 major veins, 3 major arteries, 2 important nerves, and 2 important connective tissue structures - name them
superifical veins - cephalic, basilic, medial cubital
brachial, ulnar, radial arteries
medial and radial nerves
biceps brachii tendon and bicipital aponeurosis
148
describe the 2 borders of the cubital fossa
lateral - brachioradialis
medial - pronator teres
superior - line connecting medial and lateral epicondyles
149
Describe what causes Volkman's ischemic contracture, as well as the consequences of such a condition
muscle fibrosis and shortening of the digital flexors cuasing the hand to curl into a tight fist (Chronic flexion) due to insufficient blood flow to this area
this happens when the brachial artery is damaged in humeral supracondylar fractures where it traverses the cubital fossa - the collateral circulation around the elbow is insufficient to compensate for the loss of blood flow
150
What happens if someone damages their median nerve?
impact varies depending on where along the median nerve the lesion occurs (at elbow, carpal tunnel, or in between) - more proximal injuries involve hand and forearm, more distal injuries manifest solely in the hand
151
What is pronator syndrome? How is it caused? What are some key symptoms?
compression of the median nerve between the humeral and ulnar heads of the pronator teres
- can be caused by muscle hypertrophy or trauma, often due to repetitive pronation
- symptoms include: pain in proximal forearm, decreased sensation in lateral palms and digits, some weakness flexing fingers and wrist (minimal)
152
What is anterior interosseous syndrome? How is it caused?
- caused by damage to interosseous nerve only, usually due to trauma
- inability to make the "OK" sign with thumb and index finger due to loss of flexor pollicis longus and lateral half of flexor digitorum profundus, as well as pronator quadratus
- not accompanied by sensory deficits or deficits of the thenar muscles unless other nerves are damaged, BUT this sign will occur in all proximal median nerve injuries in addition to other symptoms
- NO SENSORY DEFICITS
153
what sign is found in all median nerve injuries near the elbow?
abnormal pinch sign
154
What might cause a cubital fossa nerve injury? Tell me what the clinical appearance is of such an injury and what muscles (6-7) are involved. Tell me whether the clinical sign associated with this injury is a passive or active test
- may be due to trauma such as a penetrating wound to the cubital fossa or supra-epicondylar humeral fracture
- hand of the benediction: inability to flex the lateral three digits
- this sign is an ACTIVE test demonstrated ONLY when the patient is asked to make a tight fist
- loss of FDS and lateral 1/2 of FDP to prevent digits 2/3 from flexing
- loss of FPL and FPB in thenar eminence to prevent thumb from flexing
- loss of lumbricals to cause clawing of digits 2/3
- loss of abductor pollicis brevis and opponens pollicis to cause adduction and lateral rotation of thumb
- numbness on lateral palm and digits 1-3, 1/2 of digit 4
155
Describe the mechanism behind cubital tunnel syndrome and what some of the consequences of this condition are
- compression of the ulnar nerve in the cubital tunnel formed by the humeral and ulnar heads of the flexor carpi ulnaris posterior to the medial epicondyle
- symptoms are primarily numbness and paresthesia of the medial 1 1/2 digist and medial palm
- prolonged compression may lead to weakness of muscles innervated by the ulnar nerve
156
Describe what happens if the ulnar nerve is injured at the elbow or more proximally as far as a distinct sign, what kind of sign this is (active vs. passive) and what some common symptoms are
ULNAR CLAW occurs - MCP 4 and 5 joints become hyperextended with the IP joints flexed due to loss of lumbricals to these digits
- this is a PASSIVE SIGN
- patient will not be able to extend affected fingers when asked to extend their hand (also due to lumbrical loss)
- abduction/adduction of the fingers is also compromised
- prolonged damage leads to atrophy of dorsal interossei
- if damage is proximal, the medial half of the FDP is also involved
- sensation loss to medial hand
157
What is "claw hand"?
inability of the patient to make a tight fist due to loss of intrinsic muscles of the hand (and possibly FDP) to digits 4 and 5 - when the patient is asked to make a tight fist - the hand assumes a loose claw like posture
158
Tell me what the general function of the posterior compartment of the arm is, as well as its innervation
function: extension
innervation: radial nerve
159
Tell me what the general functions of the posterior forearm are, and what nerve innervates it
functions: extension, abduction, adduction, and supination of wrist
innervation: radial nerve
160
What two muscles make up the posterior compartment of the arm?
triceps brachii and anoconeus
161
triceps brachii - O, I, A, N
proximal - long head from infraglenoid tubercle of scapula, lateral head from posterior sruface of humerus superior to radial groove, medial head from posterior surface of humerus inferior to radial groove
distal - proximal end of olecranon process of ulna
actions - extension of arm, resists dislocation of arm, extension of forearm
(long head extends and adducts shoulder and elbow)
(all three heads extend elbow)
nerve - radial
162
anconeus - O, I, A, N
proximal - lateral epicondyle of humerus
distal - lateral surface of olecranon and proximal posterior surface of ulna
actions - assists in extension of forearm, stabilizes elbow joint
nerve - radial
163
brachioradialis - O, I, A, N
proximal - lateral supracondylar ridge of humerus
distal - styloid process of radius
actions - flexion of forearm
nerve - radial
164
extensor carpi radialis longus - O, I, A, N
proximal - lateral supracondylar ridge of humerus
distal - dorsal base of metacarpal 2
actions - extend and abduct wrist
nerve - radial
165
extensor carpi radialis brevis - O, I, A, N
proximal - lateral epicondyle of humerus
distal - dorsal base of metacarpal 3
actions - extends and abducts wrist
nerve - deep branch of radial
166
extensor carpi ulnaris - O, I, A, N
proximal - lateral epicondyle of humerus
distal - dorsal base of metacarpal 5
actions - extends and adducts wrist
nerve - deep branch of radial
167
extensor digitorum - O, I, A, N
proximal - lateral epicondyle of humerus
distal - extensor expansion of digits 2-5
actions - extends digits 2-5 at all joints, extends wrist
nerve - deep branch of radial
168
extensor digiti minimi - O, I, A, N
proximal - lateral epicondyle of humerus
distal - extensor expansion of digit 5
actions - extends digit 5 at all joints, extends and adducts wrist
nerve - deep branch of radial
169
supinator - O, I, A, N
proximal - lateral epicondyle of humerus, posterior olecranon process
distal - proximo-lateral radius
actions - supinate forearm
nerve - deep branch of radial
170
abductor pollicis longus - O, I, A, N
proximal - posterior ulna, radius, interosseous membrane
distal - base of metacarpal 1
actions - abducts thumb
nerve - posterior interosseus (terminal branch of deep radial)
171
extensor pollicis longus - O, I, A, N
proximal - posterior ulnar, interosseous membrane
distal - base of distal phalanx of pollex
actions - extends pollex at all joints
nerve - posterior interosseous
172
extensor pollicis brevis - O, I, A, N
proximal - posterior radius, interosseus membrane
distal - base of proximal phalanx of thumb
action - extends thumb at MCP joint
nerve - posterior interosseus
173
extensor indicis - O, I, A, N
proximal - posterior ulna, interosseous memrbane
distal - extensor expansion of digit 2
action - extends digit 2 at all joints and helps extend wrist
nerve - posterior interosseous
174
name two important landmark areas of the posterior arm forearm/hand
triangular interval, anatomical snuff box
175
Tell me what two structures are found in the triangular interval and describe its three borders
contains radial nerve and deep brachial artery
lateral border - lateral head of triceps
medial border - long head of triceps
superior border - teres major
176
Tell me where the anatomical snuff box is found, describe its three borders, tell me what its cutaneous innervation is and what important structure is found there
- triangular fossa on the lateral dorsum of the hand, bounded by tendons
- lateral/anterior border: tendons of abductor pollicis longus and extensor pollicis brevis
- medial/posterior border: tendon of extensor pollicis longus
- proximal: extensor retinaculum
- superficial branch of radial nerve innervates the overlying skin
- contains the radial artery
177
Describe the consequences of radial nerve compression or injury in the axilla or proximal arm
- generally due to pressure of the radial nerve in the radial groove of the humerus or trauma at midshaft humeral fracture, damaging the contents of the triangular interval
- symptoms include possible weakness in triceps, loss of all muscles in the posterior compartment of the forearm (wrist and finger extensors), possible loss of superficial branch (test at dorsum of hand between thumb and index finger)
178
What is the clinical appearance of compression of the radial nerve proximally?
wrist drop - inability to extend the wrist and the fingers at the MCP; relaxed wrist assumes a flexed position because of tonus of flexors
179
What is handcuff palsy and what causes it?
- due to compression of the SUPERFICIAL branch of radial nerve at wrist, i.e. from handcuffs that are too tight
- symptoms: paresthesia or numbness over dorsum of hand between Mc 1 and 2
180
Describe the importance and location of the axillary nerve
- other terminal branch of posterior cord, located within quadrangular space
- motor to deltoid and teres minor, cutaneous to lateral arm
- damage leads to atrophy of the deltoid, which can happen in glenohumeral dislocation
181
Tell me what the extensor expansion is made up of, where it's located, and what its purpose is
- triangular expansions of extensors tendons (aka dorsal digital expansions), insert onto middle and distal phalanges
- muscles inserting onto extensor expansions act on all digital joints (MCP, PIP, DIP)
- serve as insertion points for long extensors of the digits as well as intrinsic hand muscles (interossei, lumbricals)
- long extensor tendons connected by tendinous bands that limit independent extension of digits
182
posterior interosseous nerve innervates the 4 ABLE muscles - name them
abductor pollicis longus
extensor pollicis brevis
extensor pollicis longus
extensor indicis
183
Name the 4 proximal carpals
scaphoid
lunate
triquitrum
pisiform (attachment for flexor carpi ulnaris and flexor retinaculum)
184
Name the 4 distal carpals
trapezium
trapezoid
capitate
hamate (hook on it called hamulus)
185
How many metacarpals are there?
five
186
How many phalanges are there?
proximal, middle, and distal phalanges (thumb has no middle phalanx)
187
Tell me what kind of joints the intercarpal and caropmetacarpal (CMC) joints are what movements they permit
plane joints that allow sliding/translation
188
Tell me what kind of joint the trapeziometacarpal joint is and movements it permits
- specialized CMC joint, saddle type
- flexion, extension, abduction, adduction, opposition
- common area for arthritis and dislocation problems
189
Tell me what type of joint the Metacarpophalangeal (MCP) joints are and what movements they permit
- condyloid joints except the 1st MCP (trapeziometacarpal) joint
- movements: flexion, extension, abduction, adduction
190
Tell me what kind of joints the interphalangeal joints are and what movements they permit
- hinge joints (proximal and distal joints except thumb which only has one IP joint)
- movements: flexion, extension
191
describe what causes a scaphoid fracture and what the consequences of such an injury are
- most commonly fractured bone
- caused by falling on an outstretched hand
- can be difficult to diagnose radiographically
- scaphoid receives its blood supply from the distal end near the trapezium, proximal portion does not have its own blood supply, if left untreated can lead to avascular necrosis of proximal scaphoid
192
What is a boxer's fracture?
fracture of the 5th metacarpal shaft, sometimes the 4th as well
- due to transmission of sudden force through medial portion of hand with a closed fist as in punching or during a fall
193
Name and describe the four primary actions of the fingers
1. flexion - curling fingers towards the palm (anterior motion)
2. extension - straightening fingers (posterior motion)
3. abduction and adduction - defined in reference to a line running proximo-distally through digit 3
- - abduction: spreading fingers away from this line
- -adduction: bringing fingers towards this line
**3rd finger can abduct in both directions, but CANNOT ADDUCT
194
Describe the primary movements of the thumb
- thumb is rotated 90 degrees relative to the fingers, so movements are also rotated 90 degrees
1. flexion - curling thumb toward palm
2. extension - straightening thumb (moving toward radius - medial/lateral)
3. abduction - moving thumb anteriorly away from fingers
4. adduction - moving thumb back toward the fingers (posteriorly)
5. opposition** - moving the tip of the thumb to touch the tips of the other fingers
195
what four movements make up the opposition motion of the thumb?
flexion, abduction, adduction, rotation of MC 1
196
What is Jersey finger? How is it caused and what are the consequences?
- rupture or avulsion of flexor digitorum profundus tendon from base of distal phalanx
- caused by forceful traction on distal phalanx when DIP is in flexion (as when grabbing the back of an injury)
- leads to inability to flex DIP joint of affected digit
197
What is mallet finger? How is it caused? What are the consequences of such a condition?
- sudden impact forces distal phalanx into hyperflexion
- avulsion (tearing) of extensor expansion from base of distal phalanx
- leads to inability to extend DIP joint of affected digit >> stuck in flexion
- resulting finger resembles a mallet
198
Name the 3 sub-compartments of the anterior compartment of the hand
thenar, hypothenar, central
199
Tell me the functions of the thenar compartment of the hand, as well as what its innervation is, and the muscles that make it up
function: flexion, abduction, and opposition of thumb
muscles: flexor pollicis brevis (superficial head and deep head?), abductor pollicis brevis, opponens pollicis (deep)
innervation: recurrent branch of median nerve
200
Tell me the functions of the hypothenar compartment (pinky side) of the hand, as well as its innervation, and the muscles that make it up
function: flexion, opposition and abduction of the 5th digit
muscles: opponens digiti minimi (deep), flexor digiti minimi, abductor digiti minimi
innervation: deep branch of the ulnar nerve
201
Tell me the functions of the central compartment of the hand, as well as its innervation, and the muscles that make it up
function: abduction of the central 3 digits, adduction of the thumb and 5th digit, assists in flexion of the MCP and extension of the IP joints
muscles: lumbricals (lateral 2 is median nerve), palmar and dorsal interossei, abductor pollicis transverse and oblique head
202
there is no "posterior compartment" of the hand - tell me about the muscles and innervation there, though
- all extensors are extrinsic muscles of the hand
- radial nerve only provides cutaneous innervation
- all muscles are innervated by anterior division nerves - median and ulnar
203
What is the palmar aponeurosis? What is its function? What muscles insert onto it?
- thickening of the deep fascia of the hand, partially defines the boundaries of the thenar, hypothenar and central compartments
- thick fibrous layer closely interconnected with superficial palmar fascia and skin
- palmaris longus and brevis insert onto it
204
What is dupuytren's contracture? What causes it? What are some of the symptoms?
- most common on medial side of palm associated with 4th and 5th digits
- more common in males age 50 and over
- treatment is primarily surgical
- begins as painless nodules in longitudinal bands of palmar aponeurosis
- pulls the ring and little fingers into partial flexion at the MP and PIP joints
- often bilateral
205
Tell me what 3 muscles are considered the thenar muscles, what their function is, and what nerve innervates them
- muscles that mobilize the thumb and make up the thenar eminence
- abductor pollicis brevis, flexor pollicis brevis (deep head innervated by deep branch of ulnar nerve), opponens pollicis
- nerve is recurrent branch of median nerve
206
Tell me which 3 muscles are considered the hypothenar muscles and what their innervation is
- abductor digiti minimi, flexor digiti minimi brevis, opponens digiti minimi
- nerve is deep branch of ulnar nerve
207
There are 4 major muscles (3 are groups) that make up the central compartment of the hand - name them
lumbricals, dorsal interossei, palmar interossei, adductor pollicis
208
lumbricals of the hands - O, I, A, N
origin: tendon of flexor digitorum profundus
insertion: extensor expansion
actions: flex MCP joint, extend IP joints
nerves: lateral 2 innervated by median nerve, medial 2 innervated by deep branch of ulnar nerve
209
dorsal interossei of the hand - actions, insertion, innervation
- abduct (DAB) digits 2-4, digit 3 has two of them
- insert on extensor expansion
- deep branch of ulnar nerve
210
palmar interossei of the hand - actions, insertion, innervation
- adduct (PAD) digits 2, 4, 5
- insert on extensor expansion
- deep branch of ulnar nerve
211
adductor pollicis - innervation and action
- acts like a palmar interosseous muscel in that it adducts the thumb
- deep branch of ulnar nerve
212
palmaris brevis - Location, insertion, innervation
- overlies hypothenar eminence
- inserts onto palmar aponeurosis
- innervated by superficial branch of ulnar nerve
213
What are the 2 major arteries that go to the hand?
ulnar and radial
214
The ulnar artery gives off two major branches - what are they?
- deep branch of the ulnar artery (given off in ulnar canal)
- superficial palmar arch
215
the superficial palmar arch, which comes off the ulnar artery, gives off 2 kinds of arteries - what are they?
- common plantar digital arteries (3) >> give off proper palmar digital arteries (6-7)
- proper palmar digital artery to fifth digit
216
the radial artery gives off 4 major arteries in the hand - name them
- superficial palmar branch of radial artery
- princeps pollicis artery on palmar side (Gives off proper palmar digital arteries of thumb)
- radial indicis artery (may come from princeps pollicis)
- deep palmar arch (gives off palmar metacarpal arteries x3)
217
describe the anastomosis path of the ulnar to radial arteries
ulnar > superficial palmar arch > superficial palmar branch of radial > radial
218
describe the anastomosis path of radial to ulnar arteries
radial > deep palmar arch > deep branch of ulnar > ulnar
219
The Allen's test does what clinically?
tests for ulnar and radial artery anastomoses in the hand
220
tell me what areas of the skin the ulnar nerve innervates
- medial half of palm
- medial half of dorsum of hand
- dorsum and palmar aspects of medial one and a half digits (except lateral dosral tip of 4th digit which uses median nerve)
221
tell me what areas of the skin the median nerve innervates
- lateral half of palm
- palmar aspect of lateral 3 and 1/2 digits and dorsal nail beds of those digits (Except dorsal nail bed of thumb which uses radial nerve)
222
tell me what area of the skin the radial nerve innervates
lateral dorsum of hand including the entire dorsum of the thumb
223
the ulnar nerve divides into a superficial branch and a deep branch in the ulnar canal - tell me what each branch innervates
deep branch provides motor innervation to:
- -hypothenar muscles
- -medial 2 lumbricals
- -muscles in the central compartment
- -deep head of flexor pollicis brevis
superficial branch provides cutaneous innervation to palm and palmar digits:
--also provides innervation to palmaris brevis
224
what is the ulnar canal?
- it's called Guyon's canal
- narrow space between pisiform and hamate through which the ulnar nerve passes
- common site of nerve compression
225
describe what happens with a type I ulnar canal compression
- ulnar trunk is compressed in proximal canal
| - leads to sensory (abnormal sensation) and motor (muscular weakness) syndrome
226
describe what happens with a type II ulnar canal compression
- deep branch is compressed in distal canal
| - leads to motor symptoms only (muscle weakness)
227
describe what happens with a type III ulnar canal compression
- superficial branch is compressed in distal canal
| - leads to sensory symptoms only (abnormal sensation)
228
injury to the ulnar nerve at the wrist leads to ulnar claw - please describe the consequences of this condition
- extension at MCP joint of medial 2 digits
- flexion at IP joints of medial 2 joints
- due to loss of medial 2 lumbricals
- clawing is seen at rest
- when asked to extend digits patient will be unable to do so
229
in a patient with ulnar claw, tell me what actions they can and cannot perform, as well as the consequences of a long term injury
- can flex medial 2 digits because long flexors are intact
- cannot make a tight fist because intrinsic hand muscles are compromised
- long term injury leads to wasting of intrinsic hand muscles innervated by ulnar nerve (most obviously dorsal interossei)
230
tell me what 3 major branches of nerves come off the median nerve in the hand
- recurrent branch: motor innervation to thenar muscles
- common and proper palmar digital nerves: cutaneous innervation to palmar digits (1-3, half of 4) and dorsal nail beds (2-3 , half of 4)
- palmar branches: branches before carpal tunnel, provides cutaneous innervation to lateral palm
231
Name the muscles that are innervated by the median nerve (LOAF)
- lateral 2 lumbricals
- opponens pollicis
- abductor pollicis brevis
- flexor pollicis brevis
232
What is the carpal tunnel and what are the major structures that make it up?
- the narrow passage into the hand between the carpals posteriorly and the flexor retinaculum anteriorly
- flexor retinaculum = transverse carpal ligament
- attached laterally to the scaphoid and trapezium
- attached medially to the pisiform and hook of hamate
233
tell me what nerve and 3 muscle tendons are found in the carpal tunnel
median nerve
tendons of flexor digitorum superficialis, flexor digitorum profundus, flexor pollicis longus
234
inflammation of structures within the carpal tunnel lead to compression of the median nerve - tell me some common symptoms and what happens if the injury is prolonged
- common symptoms include abnormal sensation in lateral 3 digits and weakness of thenar muscles
- prolonged compression leads to APE HAND
235
what is ape hand?
- loss of fleshy prominence at base of thumb, superficially resembling the hand of an African ape
- thumb will be adducted (due to loss of abductor pollicis brevis) and laterally rotated (due to loss of opponens)
- loss of lateral 2 lumbricals will lead to clawing of digits 2 and 3
236
loss of recurrent branch of the median nerve leads to ape hand but not what?
no sensory deficits
no loss of lumbricals
