Upper Limb Flashcards
(236 cards)
1
Q
Features of medial 2/3rd of clavicle
A
- Convex anteriorly
- Circular in cross-section
2
Q
Features of lateral 1/3rd of clavicle
A
- Convex posteriorly
- Flattened cross-section
3
Q
What attaches clavicle to 1st costal cartilage
A
Costoclavicular ligament
4
Q
What attaches clavicle to coracoid process
A
Coracoclavicular ligament (conoid tubercle)
5
Q
Significance of clavicle in embryology
A
First bone to ossify in the fetus
6
Q
Where is the clavicle most likely to fracture
A
Junction between middle and outer thirds
7
Q
What are the three attachments of the coracoclavicular ligament
A
- Coracoid
- Conoid tubercle of clavicle
- Trapezoid line of clavicle
8
Q
What type of joint is the ACJ
A
Plane/Gliding synovial joint
9
Q
What two ligaments make up the coracoclavicular ligament
A
- Conoid ligament
- Trapezoid ligament
10
Q
Which ribs does the scapula cover
A
2nd to 7th
11
Q
Shape and orientation of humeral head
A
- 1/3rd sphere
- Projects medially, upwards, and backwards
12
Q
What separates the greater and lesser tubercles of the humerus
A
Bicipital (intertubercular) groove
13
Q
Where is the surgical neck of humerus
A
At the junction between the shaft and head of humerus
14
Q
What lies in close proximity to the surgical neck of the humerus
A
- Axillary nerve
- Circumflex humeral vessels
15
Q
Where is the deltoid tuberosity
A
Anterolateral aspect of midshaft
16
Q
Where is the spiral groove of the humerus located
A
Posterior shaft
17
Q
Significance of the spiral groove
A
Home to the radial nerve which winds around the humerus between medial and lateral heads of triceps
18
Q
What part of the humerus articulates with the radial head
A
Capitulum
19
Q
What part of the humerus articulates with the humerus
A
Trochlea (with trochlea notch of humerus)
20
Q
Anterior landmarks of lower humerus
A
Coronoid fossa (accepts coronoid process of ulna)
21
Q
Posterior landmarks of lower humerus
A
Olecranon fossa (accepts olecranon of ulna)
22
Q
Where does the ulna nerve lie with respect of the medial condyle of humerus
A
Lies in groove on the posterior aspect
23
Q
Significance of ulna tuberosity
A
Attachment site for brachialis
24
Q
Direction of interosseous membrane fibres
A
Oblique course inferiorly from radius medially to ulna
25
List the proximal row of carpal bones from lateral to medial
1. Scaphoid
2. Lunate
3. Tiquetral
4. Pisiform
26
Proximal articulations of the Triquetral bone
Articular disc of the distal radio-ulnar joint
27
List the distal row of carpal bones from lateral to medial
1. Trapezium
2. Trapezoid
3. Capitate
4. Hamate
28
Describe the structure of the proximal ulna
- Olecranon process (superior)
- Trochlear notch
- Coronoid process (contains radial notch)
29
List the articulations of the trapezium
- Scaphoid
- Lunate
- 1st and 2nd metacarpal
30
List the articulations of the trapezoid
- Scaphoid
- Trapezium
- Capitate
- 2nd metacarpal
31
List the articulations of the capitate
- Scaphoid
- Lunate
- Trapezoid
- Hamate
- 2nd metacarpal
- 3rd metacarpal
- 4th metacarpal
32
Articulations of the 2nd metacarpal
- Trapezium
- Trapezoid
- Capitate
33
List the articulations of the hamate
- Lunate
- Capitate
- Triquetrum
- 4th metacarpal
- 5th metacarpal
34
What deepens the glenohumeral joint
Glenoid labrum
35
Weakest part of the GH capsule
Inferior part
36
Describe the attachments of the GH capsule
Around the epiphyseal line of glenoid and humeral head
37
Medial margin of GH capsule
Margin of glenoid cavity
38
Lateral margin of GH capsule
Anatomical neck of humerus
39
What tendon passes through the GH joint
Long head of biceps tendon
40
List the 4 ligaments of the GH joint
1. Glenohumeral
2. Coracohumeral
3. Transverse humeral
4. Coraco-acromial
41
Describe the glenohumeral ligaments
- Three bands = superior, middle, inferior
- Only evident on the internal aspect of the capsule
- Blend with the fibrous capsule as it attaches to neck of humerus
42
Course of the coracohumeral ligament
Passes from coracoid process to anterior aspect of greater tubercle of humerus
43
Describe the tranverse humeral ligament
- Broad band
- Runs from greater to lesser tubercle
- Creates canal that transmits the synovial sheath and tendon of biceps brachii
44
What forms the coraco-acromial arch
- Acromion
- Coracoid process
- Coraco-acromial ligament
45
Function of the coraco-acromial ligament
Prevents superior displacement of the humerus
46
Blood supply of the GH joint
Anterior and posterior circumflex humeral arteries (branches of the suprascapular artery)
47
Innervation of the GH joint
- Suprascapular
- Axillary
- Lateral pectoral
48
Which muscles cause flexion of the shoulder
- Pec major
| - Anterior fibres of deltoid
49
What muscle causes extension of the shoulder
- Deltoid (spinal part)
50
Which muscle initiates abduction of the shoulder
Supraspinatus
51
Which muscles tense the articular capsule of the GH joint
- Subscapularis
| - Infraspinatus
52
Which muscle resists downward dislocation of the GH joint
Deltoid (also long head of triceps, coracobrachialis, short head of biceps brachii)
53
What type of joint is the sternoclavicular joint
Sadlle-type synovial
54
List the ligaments of the SC joint
- Anterior and posterior sternoclavicular ligaments
- Interclavicular ligament
- Costo-clavicular ligament
55
Blood supply of SC joint
- Internal thoracic
| - Suprascapular
56
What are the articular surfaces of the elbow joint
- Humeral = trochlea (medial) and caputulum (lateral)
- Ulna = trochlear notch
- Radius = superior aspect of head
57
Outline the ligaments of the elbow joint
- Radial collateral ligament = lateral epicondyle of humerus to blend with anular ligament of radius
- Medial collateral ligament (triangular) = medial epicondyle of humerus to coronoid process and olecranon of the ulna
58
Function of the Anular ligament
Joint proximal radius and ulna
59
Describe the joint capsule of the proximal radio-ulnar joint
Continuous with the elbow joint
60
Which muscle elicit supination of the forearm
- Supinator
| - Biceps brachii (when force required)
61
Blood supply of the proximal radio-ulnar joint
Radial portion of the peri-articular arterial anastomosis of the elbow
62
Describe the movement of the distal radio-ulnar joint
Radius moves around a relatively fixed ulna
63
Blood supply of distal radio-ulnar joint
Anterior and posterior interosseous
64
What type of joint is the radio-carpal joint
Condyloid synovial joint
65
Movements permitted by the radio-carpal joint
- Flexion
- Extension
- Adduction
- Abduction
- Circumduction
66
Surface marker of radio-carpal joint line
PROXIMAL wrist crease
67
Distal articular surfaces of the radio-carpal joint
- Scaphoid
- Lunate
- Truquetral
68
List the ligaments of the radio-carpal joint
1. Palmar radiocarpal ligaments
2. Dorsal radiocarpal ligaments
3. Ulnar collateral ligament
4. Radial collateral ligament
69
Course of ulnar collateral ligament
Ulnar styloid to triquetral
70
Course of radial collateral ligament
Radial styloid to scaphoid
71
What type of joint is the CMC joint of the thumb
Saddle-type synovial
72
What prevents the MCP joints of the fingers spreading during a tight drip
Deep transverse ligaments
73
Course of Pectoralis major
1. Clavicular Head = anterior surface of medial 1/2 clavicle
2. Sternocostal Head = anterior surface of sternum and superior 6 costal cartilages
3. Lateral lip of intertubercular sulcus of humerus
74
Innervation of Pectoralis major
Medial and lateral pectoral nerves
75
Course of Pectoralis minor
1. 3rd-5th ribs near costal cartilage
| 2. Medial border and upper surface of coracoid process of scapula
76
Innervation of Pectoralis minor
Medial pectoral nerve
77
Action of Pectoralis minor
Assists serratus anterior in drawing scapula forwards and depresses the point of the shoulder
78
Course of subclavius
1. Junction of 1st rib and costal cartilage
| 2. Inferior surface of middle 1/3rd of clavicle
79
Innervation of Subclavius
Nerve to subclavius (C5, C6)
80
Course of serratus anterior
1. External surfaces of lateral part of ribs 1-8
| 2. Anterior surface of medial border of scapula
81
Innervation of serratus anterior
Long thoracic nerve (C5-7)
82
Course of trapezius
1. Medial superior nuchal line/external occipital protuberance/nuchal ligament/spinous process C7-T12
2. Lateral 1/3rd clavicle/acromion and spine of scapula
83
Innervation of trapezius
Spinal accessory nerve (CN 11)
84
Course of latissimus dorsi
1. Spinous processes of inferior 6 thoracic vertebrae/thoracolumbar fascia/inferior 3/4 ribs
2. Floor of intertubercular sulcus of humerus
85
Innervation of latissimus dorsi
Thoracodorsal nerve (C6-8)
86
Course of levator scapulae
1. Posterior tubercles of transverse processes of C1-4
| 2. Medial border of scapula
87
Innervation of levator scapulae
Dorsal scapular and cervical nerves (C3/4)
88
Innervation of rhomboid major and minor
Dorsal scapular nerve
89
Course of Deltoid
1. Lateral 1/3rd clavicle/acromion/spine of scapula
| 2. Deltoid tuberosity of humerus
90
Innervation of Deltoid
Axillary nerve (C5/6)
91
Course of supraspinatus
1. Supraspinatus fossa of scapula
| 2. Superior facet of greater tubercle of humerus
92
Innervation of supraspinatus
Suprascapular nerve (C4-6)
93
Course of infraspinatus
1. Infraspinatus fossa of scapula
| 2. Middle facet of greater tubercle of humerus
94
Innervation of infraspinatus
Suprascapular nerve (C5/6)
95
Course of teres minor
1. Middle part of lateral border of scapula
| 2. Inferior facet of greater tubercle of humerus
96
Innervation of teres minor
Axillary nerve (C5/6)
97
Course of teres major
1. Posterior surface of inferior angle of scapula
| 2. Medial lip of intertubercular sulcus of humerus
98
Innervation of teres major
Lower subscapular nerve (C5/6)
99
Course of subscapularis
1. Subscapular fossa of anterior surface of scapula
| 2. Lesser tubercle of humerus
100
Innervation of subscapularis
Upper and lower subscapular nerve (C5-7)
101
Muscles involved in medial (IR) rotation of humerus
1. Subscapularis
2. Teres major
3. Latissimus dorsi
4. Pectoralis major
5. Anterior part of Deltoid
102
Muscles involved in lateral rotation (ER) of humerus
1. Infraspinatus
2. Teres minor
3. Lateral part of Deltoid
103
Course of Biceps brachii
1. SH = tip of coracoid, LH = supraglenoid tubercle of scapula
2. Tuberosity of radius and fascia of forearm via bicipital aponeurosis
104
Innervation of biceps brachii
Musculocutaneous nerve (C5, C6, C7)
105
Course of coracobrachialis
1. Tip of coracoid
| 2. Medial 1/3rd of medial humeral surface
106
Innervation of coracobrachialis
Musculocutaneous nerve (C5, C6, C7)
107
Course of brachialis
1. Distal 1/2 of humeral anterior surface
| 2. Coronoid process and tuberosity of ulna
108
Innervation of brachialis
Musculocutaenous and radial nerve
109
Function of biceps brachii
- Supinates forearm
- Flexes forearm when supine
- Short head resists dislocation
110
Function of coracobrachialis
- Helps flex and adduct arm
| - Resists dislocation
111
Function of brachialis
Flexes forearm in all positions
112
Which nerve root does the biceps tendon reflex test
C6
113
Course of triceps brachii
1. LH = infraglenoid tubercle of scapula, Lateral H = posterior surface of humerus, Medial H = posterior surface of humerus
2. Proximal end of olecranon of ulna and fascia of forearm
114
Innervation of triceps brachii
Radial nerve (C6, C7, C8)
115
Course of anconeus
1. Lateral epicondyle of humerus
| 2. Lateral surface of olecranon and superior part of posterior surface of ulna
116
Innervation of anconeus
Radial nerve (C7, C8, T1)
117
List the muscles of the anterior compartment of the arm
1. Biceps brachii
2. Brachialis
3. Coracobrachialis
118
Function of the anterior compartment of the forearm
Flexors and pronators
119
Function of the posterior compartment of the forearm
Extensors and supinator
120
List the layers of the anterior compartment of the forearm
1. Superficial layer - all originate from common flexor tendon on medial epicondyle of humerus
2. Intermediate layer
3. Deep layer - all do NOT cross the elbow joint
121
List the muscles of the superficial compartment of the forearm
1. Pronator teres
2. Flexor carpi radialis
3. Palmaris longus
4. Flexor carpi ulnaris
122
List the muscles of the intermediate compartment of the anterior forearm
Flexor digitorum superficialis
123
List the muscles of the deep compartment of the anterior forearm
1. Flexor digitorum profundus
2. Flexor pollicis longus
3. Pronator quadratus
124
Describe the innervation of the anterior compartment of the forearm
All but FCU are supplied by the median nerve (Deep anterior compartment is anterior interosseous branch of median nerve)
125
Course of pronator teres
1. Ulnar head = coronoid, Humeral head = medial epicondyle
| 2. Middle convexity of lateral radial surface
126
Course of Flexor carpi radialis
1. Medial epicondyle
| 2. Base of 2nd metacarpal
127
Course of Palmaris longus
1. Medial epicondyle
| 2. Distal half of flexor retinaculum
128
Course of Flexor carpi ulnaris
1. Humeral head = medial epicondyle, Ulnar head = olecranon
| 2. Pisiform/hook of hamate/5th metacarpal
129
Course of Flexor digitorum superficialis
1. Humero-ulnar head = medial epicondyle, Radial head = superior half of anterior border
2. Shafts of medial phalanges of the medial 4 digits
130
Function of Flexor digitorum superficialis
Flexes middle phalanges at PIPs and MCPs
131
Innervation of Flexor digitorum profundus
- Medial part = ulnar nerve
| - Lateral part = anterior interosseous nerve
132
Course of Flexor digitorum profundus
1. Proximal 3/4 of medial and anterior surface of ulna and interosseous membrane
2. Bases of distal phalanges 2-5
133
Course of Flexor pollicis longus
1. Anterior surface of radius and interosseous membrane
| 2. Base of distal phalanx of thumb
134
Course of Pronator quadratus
1. Distal 1/4 of anterior surface of ulna
| 2. Distal 1/4 of anterior surface of radius
135
Function of Flexor digitorum profundus
Flexes DIPs
136
When do the extensor tendons of the forearm get provided with synovial sheaths
As the tendon passes over the dorsum of the wrist
137
How can the muscles of the posterior compartment of the forearm be FUNCTIONALLY divided
1. Muscles that extend and abduct/adduct the hand at the wrist
2. Muscles that extend the medial 4 fingers
3. Muscles that extend or abduct the thumb
138
Course of brachioradialis
1. Supra-condylar ridge of humerus
| 2. Lateral surface of distal radius
139
Function of brachioradialis
Weak flexion of forearm, maximal when mid-pronated
140
Course of extensor carpi radialis longus
1. Lateral supracondylar ridge of humerus
| 2. Dorsal aspect of base of 2nd metacarpal
141
Course of extensor carpi radialis brevis
1. Lateral epicondyle
| 2. Dorsal aspect of base of 3rd metacarpal
142
Course of extensor digitorum
1. Lateral epicondyle
| 2. Extensor expansion of medial 4 digits
143
Course of extensor digiti minimi
1. Lateral epicondyle
| 2. Extensor expansion of 5th digit
144
Course of extensor carpi ulnaris
1. Lateral epicondyle and posterior border of ulna
| 1. Dorsal aspect of base of 5th metacarpal
145
List the muscles of the superficial layer of the posterior compartment of the forearm
1. Brachoradialis
2. Extensor carpi radialis longus
3. Extensor carpi radialis brevis
4. Extensor digitorum
5. Extensor digiti minimi
6. Extensor carpi ulnaris
146
Course of supinator
1. Lateral epicondyle/radial collateral ligaments/supinator fossa/crest of ulna
2. Proximal 1/3rd of radius laterally
147
Course of extensor indices
1. Posterior surface of distal 1/3rd ulna/interosseous membrane
2. Extensor expansion of 2nd digit (index finger)
148
Course of Abductor pollicis longus
1. Posterior surface of proximal half or radius and ulna/interosseous membrane
2. Base of 1st metacarpal
149
Course of extensor pollicis longus
1. Posterior surface of proximal half or radius and ulna/interosseous membrane
2. Dorsal aspect of base of distal phalanx of thumb
150
Course of extensor pollicis brevis
1. Posterior surface of distal 1/3rd radius/interoessous membrane
2. Dorsal aspect of base of proximal phalanx of thumb
151
Muscles of forearm innervated by radial nerve
- Brachioradialis
| - Extensor carpi radialis longus
152
Muscles of forearm innervated by Deep branch of radial nerve (C7, C8)
- Extensor carpi radialis brevis
- Extensor digitorum
- Extensor digit minimi
- Extensor carpi ulnaris
- Supinator
153
Muscles of forearm innervated by posterior interosseous nerve (continuation of deep branch of radial nerve)
- Extensor indices
- Abductor pollicis longus
- Extensor pollicis longus
- Extensor pollicis brevis
154
Anterior border of anatomical snuffbox
Tendons of extensor pollicis brevis and abductor pollicis longus
155
Posterior border of anatomical snuffbox
Tendon of extensor pollicis longus
156
Proximal border of anatomical snuffbox
Styloid process of radius
157
Floor of anatomical snuffbox
- Trapeziuim
| - Scaphoid
158
Contents of the anatomical snuffbox
Radial artery
159
Contents of the thenar eminence
- Abductor pollicis brevis
- Opponens pollicis
- Flexor pollicis brevis
160
Contents of the hypothenar eminence (Muscles of the little finger)
- Opponens digiti minimi
- Flexor digiti minimi brevis
- Abductor digiti minimi
161
Describe the interossei
- 4 palmar = adduct fingers and flex MCPs
| - 4 dorsal = abducts fingers and extend IPJs
162
Innervation of the interossei
Deep ulnar branch of the ulnar nerve
163
Describe the lumbricals
- Origin = deep flexor tendon
- Insertion = dorsal extensor hood
- Innervation: 1st and 2nd = median, 3rd and 4th = deep branch of ulnar
- Function = flex MCPs and extend ICPs
164
Muscle of the hand innervated by median nerve
```
L = lumbricals 1 and 2
O = opponens pollicis
A = Abductor pollicis brevis
F = flexor pollicis brevis
```
165
How many bones make up the hand
- 8 carpal
- 5 metacarpal
- 14 phalanges
166
Which finger is not attached to the interossei muscles
Middle finger
167
Describe the course of the axillary artery
1. Begins at the lateral border of 1st rib as continuation of subclavian artery
2. Passes posterior to pectorlais minor
3. Ends at the inferior border of teres major by becoming brachial artery
168
What structure divides the axillary artery into 3 parts
Pectoralis minor
169
Describe the 1st part of the axillary artery and its branches
- Between lateral border of 1st rib and medial border of pec minor
- Enclosed by axillary sheath with axillary vein which is surrounded by cords of brachial plexus
- 1 branch = superior thoracic artery
170
Describe the 2nd part of the axillary artery and its branches
- Lies posterior to pectoralis minor
- 2 branches:
A) Thoracoacromial artery
B) Lateral thoracic arteries
171
Describe the 3rd part of the axillary artery and its branches
- Extends from lateral border of pec minor to inferior border of teres major
- 3 branches:
A) Subscapular artery
B) Anterior circumflex humoral artery
C) Posterior circumflex humoral artery
172
Distribution of superior thoracic artery
- Serratus anterior
| - 1st/2nd intercostal spaces
173
Distribution of lateral thoracic artery
Lateral aspect of the breast
174
Describe the course and distribution of profunda brachii artery
- Branch of brachial artery
- Accompanies radial nerve along radial groove of humerus
- Supplies posterior compartment of arm
175
Describe the anatomical relations of the axillary sheath (1st part of axillary artery)
- Within the sheath = medial cord of brachial plexus lies behind artery
- Anteriorly = clavipectoral fascia
- Superolaterally = lateral and posterior cords of brachial plexus
- Inferomedially = axillary vein
176
Describe the anatomical relations of the second part of the axillary artery
- Posterior = posterior cord of brachial plexus and subscapularis
- Anteriorly = pectoralis minor and major
- Laterally = lateral cord of brachial plexus
- Medially = medial cord of brachial plexus separates it from brachial vein
177
Describe the anatomical relations of the third part of the axillary artery
- Posterior = subscapularis, latissimus dorsi, teres major
- Axillary and radial nerve lies between it and subscapularis
- Anterior = medial root of median nerve
- Laterally = median and musculocutaneous nerves and corcacobrachialis
- Medially = axillary vein
178
Where is the quadrangular space
Gap in the posterior wall of the axilla, allowing access to the posterior arm and shoulder area
179
Contents passing through the quadragular space
Axillary nerve and posterior circumflex humeral artery (branch of the 3rd part of axillary artery)
180
Location and function of the clavipectoral fascia
- Under pec major
| - Protects axillary vessels
181
Bounds of the clavipectoral triangle
- Pec major
- Deltoid
- Clavicle
182
Contents of the clavipectoral triangle
- Cephalic vein enters axilla
| - Medial and lateral pectoral nerves leave
183
Course of the brachial artery
- Begins at lower border of teres major
- Terminates in the cubital fossa at the level of the neck of the radius
- Divides into radial and ulnar arteries
184
What separates the brachial artery from the median cubital vein in the cubital fossa
Bicipital aponeurosis
185
Where is the brachial artery crossed by the median nerve
Middle of the arm
186
List the branches of the brachial artery
- Profunda brachii
| - Superior and inferior ulnar collateral arteries
187
Course of the Basilic vein
1. Originates on the medial side of the dorsal venous network of the hand
2. Passes up the forearm and arm, mostly superficial
3. Midway up humerus (border of teres major) it passes deep under the muscles
4. Anterior and posterior circumflex humeral veins drain into it at the lower border of teres major
5. Joined by medial brachial vein before draining into axillary vein
188
Course of the Cephalic vein
1. Originates from lateral side of dorsal venous arch of the hand
2. Crosses the anatomical snuffbox and travels laterally up the arm
3. Pierces deep fascia of deltopectoral groove to join axillary vein
189
What forms the axillary vein
1. Basilic vein
| 2. Brachial vein
190
What accompanies the basilic vein on its course
Medial cutaneous nerve
191
Course of the ulnar artery
1. Begins at the middle of the antecubital fossa
2. Passes obliquely downwards
3. Follows ulnar border to the wrist
4. Crosses over flexor retinaculum
5. Divides into superficial and deep volar arches
192
Anatomical relations of the ulnar artery
- Anterior = pronator teres, FCU, palmaris longus
- Lies on = brachialis, FDP
- Median nerve crosses artery after 2.5cm
- Ulnar nerve lies medial to the lower 2/3rd of the artery
193
What separates the ulnar artery from the median nerve
Ulnar head of pronator teres
194
Borders of Guyon's (Ulnar) Canal
- Medial (ulnar) = pisiform, abductor digiti minimi
- Lateral = hook of hamate
- Roof = palmar carpal ligament
- Floor = flexor retinaculum and hypothenar muscles
195
Contents of Guyon's canal
- Ulnar nerve bifurcates in canal to superficial (sensory) and deep (motor) branches
- Ulnar artery (located on radial aspect of the ulnar nerve)
- Venae comitantes of ulnar artery
- Lymphatic vessels
196
Course of the radial artery
1. Commences at level of radial neck lying on biceps tendon
2. Overlapped by brachioradialis
3. Lies between brachioradialis and FCR in distal forearm
4. Passes deep to APL and EPB tendons to enter snuffbox
197
What forms the brachial plexus
Anterior rami of C5-T1 form the roots of the plexus
198
Describe the course of the brachial plexus from neck to axilla
1. Roots pass in gap between anterior and middle scalene
2. As they enter the posterior triangle the trunks are formed
4. Passes deep to clavicle and suprascapular vessels
5. Enters axilla where the cords are formed
199
How is the brachial plexus divided
- Roots
- Trunks
- Divisions
- Cords
- Branches
(Real Teenagers Drink Cold Beer)
200
Where are the roots of the brachial plexus located
- In posterior triangle
| - Pass between anterior and middle scalene
201
Where are the trunks of the brachial plexus located
- Posterior to middle 1/3rd of clavicle
- Upper and middle trunks related superiorly to subclavian artery
- Lower trunk passes over 1st rib posterior to subclavian artery
202
Where are the divisions of the brachial plexus
Apex of the axilla
203
What forms the basis of the names of the cords of the brachial plexus
By their relation to the axillary artery
204
Outline which roots become which trunks of the brachial plexus
1. Superior trunk = C5 and C6
2. Middle trunk = C7
3. Inferior trunk = C8 and T1
205
Describe how trunks become divisions of the brachial plexus
All trunks divide into anterior and posterior divisions
206
Describe how the divisions form the cords of the brachial plexus
- Posterior divisions all unite to form Posterior cord (C5-8)
- Anterior divisions of superior and middle trunks form Lateral cord (C5-7)
- Anterior division of the inferior trunk continues as the Medial cord (C8, T1)
207
Where do the branches of the brachial plexus form
Beginning of the 3rd part of the axillary artery
208
What nerves arise from the lateral cord
- Musculocutaneous
- Median (in tandem with medial cord)
- Lateral pectoral nerve
209
What nerves arise from the posterior cord
- Axillary
- Radial
- Upper and lower subscapular nerves
- Thoracodorsal nerve
210
What nerves arise from the medial cord
- Ulnar
- Median (in tandem with lateral cord)
- Medial brachial cutaneous nerve
- Medial antebrachial cutaneous nerve
211
Course of musculocutaneous nerve
1. Branch of lateral cord
2. Penetrates coracobrachialis
3. Passes obliquely between biceps brachii and brachialis to lateral side of arm
4. Pierces deep fascia lateral to tendon of biceps brachii above the elbow
5. Continues in the forearm as the lateral cutaneous nerve
212
What is innervated by the musculocutaneous nerve
- Coracobrachialis
- Biceps brachii
- Brachialis
213
Course of the median nerve
1. Arises from medial and lateral cord of the plexus
2. Initially anterior to 3rd part of axillary artery
3. Descends lateral to brachial arteries before crossing over artery to medial side
4. Passes deep to bicipital aponeurosis and median cubital vein at the elbow
5. Passes between the heads of pronator teres and runs on the deep surface of FDS
6. Becomes superficial at the wrist between tendons of FDS and FCR but deep to palmaris longus
7. Passes deep to flexor retinaculum but anterior to long flexor tendons in the tunnel
214
Branches of the median nerve in the forearm
- Pronator teres
- Pronator quadratus
- FCR
- Palmaris longus
- FDS
- FPL
- FDP (radial half)
215
Motor branches of the median nerve in the hand
- L = Lateral 2 lumbricals
- O = Opponens pollicis
- A = ABductor pollicis brevis
- F = Flexor pollicis brevis
216
Course of the axillary nerve
1. Terminal branch of posterior cord of plexus
2. Descends posterior to axillary artery
3. Passes through quadrangular space with posterior circumflex humeral vessels
4. Divides into anterior and posterior branches
5. Innervates deltoid muscle and patch of skin over deltoid
217
Course of the radial nerve
1. Continuation of posterior cord of plexus
2. Lies posterior to axillary artery on subscapularis, latissimus dorsi and teres major
3. Enters arm between brachial artery and long head of triceps medial to humerus
4. Spirals around the posterior surface of humerus in its groove
5. Pierces intermuscular septum at the distal 1/3rd of lateral border and descends in front of lateral epicondyle
6. Lies deep between brachialis and brachioradialis where it divides into superficial and deep branches
7. Deep branch crosses the supinator to become posterior interosseous branch
218
Distribution of radial nerve
- Triceps
- Anconeus
- Brachioradialis
- Extensor carpi radialis
219
Distribution of posterior interoesseous branch
- Supinator
- ECU
- Extensor digitorum
- Extensor indices
- Extensor digiti minimi
- EPL
- EPB
- APL
220
Course of the ulnar nerve
1. Continuation of medial cord of plexus
2. Descends posteromedial aspect of upper arm to flexor compartment of forearm
3. Passes beneath FCU and superficially over the flexor retinaculum of the hand
221
Distribution of the muscular branch of the ulnar nerve
- FCU
| - Medial half of flexor digitorum profundus
222
List the branches of the ulnar nerve
- Muscular
- Palmar cutaneous branch
- Dorsal cutaneous branch
- Superficial branch
- Deep branch
223
Distribution of the superficial branch of the ulnar nerve
Cutaneous fibres to the anterior surfaces of the medial 1.5 digits
224
Distribution of the deep branch of the ulnar nerve
- Hypothenar muscles
- All interosseous muscles
- 3rd and 4th lumbricals
- Medial head of flexor pollicis brevis
225
Effect of ulnar nerve damage at the wrist
- Wasting and paralysis of intrinsic hand muscles (claw hand)
- Wasting of hypothenar muscles
- Loss of sensation of medial 1.5 digits
226
Effect of ulnar nerve damage at the elbow
- Radial deviation of wrist
| - Less clawing of 4th and 5th digits
227
What forms the base of the axilla
Skin and fascia of the armpit
228
Describe the bounds of the axilla
- Medial = rib cage/serratus anterior
- Lateral = bicipital groove of humerus
- Anterior = pec major and minor
- Posterior = latissimus dorsi, teres major, subscapularis
229
What forms the apex of the axilla
Clavicle, 1st rib, acromion, superior border of scapular
230
Contents of the axilla
- Brachial plexus
- Axillary artery
- Axillary vein
- Lymph nodes
- Fat
231
Borders of the antecubital fossa
- Medial = pronator teres
- Lateral = brachioradialis
- Floor = brachialis and supinator
- Roof = skin, superficial fascia, deep fascia augmented by bicipital aponeurosis
232
Contents of antecubital fossa from lateral to medial
1. Radial nerve
2. Biceps tendon
3. Brachial artery
4. Median nerve
233
Describe the flexor retinaculum
- Thick connective tissue forming roof of carpal tunnel
| - Extends from hook of hamate and pisiform to scaphoid and trapezium
234
Surface marker of entrance to carpal tunnel
Distal wrist crease
235
Contents of the carpal tunnel
- Tendon of Flexor pollicis longus (has its own sheath)
- Four tendons of Flexor digitorum superficialis
- Four tendons of Flexor digitorum profundus
- Median nerve
236
Divisions of the median nerve in the hand
1. Recurrent branch = innervates palmar skin and dorsal nail beds of lateral 3.5 fingers, lateral 2 lumbricals
2. Palmar digital branch = supplies thenar muscle group
