Upper Limb Anatomy Flashcards
(154 cards)
1
Q
What 2 bones make up the pectoral (shoulder) girdle?
A
Scapula & Clavicle
2
Q
What two bony features articulate to form the glenohumeral joint?
A
Head of the humerus and the glenoid fossa of the scapula.
Ball and socket joint
Most mobile joint in body
Loose joint capsule attached to anatomical neck of the humerus.
3
Q
What 3 joints make up the pectoral girdle?
A
- Sternoclavicular joint
- Acromioclavicular joint
- Glenohumeral joint
4
Q
Why are clavicle fractures common?
A
The clavicle transmits all force from the upper limb to the axial skeleton.
The medial fragment is usually lifted by the sternocleidomastoid; whereas the upper limb droops under its weight
5
Q
What are the 3 movements at the sternoclavicular joint?
A
- Clavicle can rotate around its own longitudinal axis
- Clavicle can be raised up to 60 degrees
- Clavicle can move 30 degrees anteriorly or posteriorly during protraction and retraction of the scapula.
6
Q
What are the movements of the scapula?
A
Elevation & depression, protraction & retraction, and upward/downward rotation.
7
Q
Which muscles elevate the scapula?
A
Muscles w/ origins above the scapula (e.g. trapezius, levator scapulae)
8
Q
Which muscles depress the scapula?
A
Muscles w/ origins below the scapula (e.g. trapezius, pectoralis minor, etc.)
9
Q
What muscles protract the scapula?
A
Muscles with origins on the anterior trunk (e.g. pectoralis, serratus anterior)
10
Q
What muscles retract the scapula?
A
Muscles with origins on posterior trunk (e.g. trapezius, rhomboids, latissimus dorsi, etc)
11
Q
What is the action of the coracoclavicular ligament?
A
Suspends the upper limb and scapula from the clavicle
12
Q
What is a shoulder separation?
A
Acromioclavicular joint dislocation. Common sports injury. In type III or higher shoulder separation, the shoulder falls away from the clavicle (tear goes through the coracoclavicular ligament)
13
Q
What is the range of motion at the acromioclavicular joint?
A
Medial rotation to 50 degrees
14
Q
What are the glenohumeral ligaments?
A
Thickenings of the anterior joint capsule
15
Q
What 4 muscles make up the rotator cuff?
A
Supraspinatus, infraspinatus, teres minor and subscapularis.
16
Q
What shoulder pathology is commonly caused by excessive extension and lateral rotation of the humerus?
A
Shoulder dislocation
Can also occur when a quarterback is hacked on the arm just as he’s ready to throw
17
Q
What is the most common position for the head of the humerus following shoulder dislocation?
A
Subcoracoid (due to the actions of strong flexors and abductors of the shoulder joint)
18
Q
What is the proximal attachment of the subscapularis muscle?
A
Subscapular fossa of scapula
19
Q
What is the distal attachment of the subscapularis muscle?
A
Lesser tubercle of humerus
20
Q
What is the action of the subscapularis muscle?
A
Medially rotates and adducts the humerus
21
Q
What is the proximal attachment of the supraspinatus?
A
Supraspinous fossa of the scapula
22
Q
What is the distal attachment of the supraspinatous?
A
Greater tubercle of humerus
23
Q
What is the action of the supraspinatous?
A
Initiates abduction of the humerus
24
Q
What is the proximal attachment of the infraspinatus muscle?
A
Infaspinous fossa of the scapula
25
What is the distal attachment of the infraspinatus muscle?
Greater tubercle of the humerus
26
What is the action of the infraspinatus?
Laterally rotates the humerus
27
What is the proximal attachment of the teres minor muscle?
Lateral border of the scapula
28
What is the distal attachment of the teres minor muscle?
Greater tubercle of humerus
29
What is the action of the teres minor muscle?
Laterally rotates the humerus
30
What 3 muscles/nerves are required to abduct the arm?
1. Supraspinatus (suprascapular nerve) to initiate abduction
2. Deltoid muscle (axillary nerve) to abduct to shoulder height
3. Trapezius muscle (accessory nerve) to above shoulder height AND by serratus anterior (long thoracic nerve)
31
What is the proximal attachment of the deltoid muscle?
Lateral spine of the scapula, acromion, lateral clavicle
32
What is the distal attachment of the deltoid muscle?
Deltoid tuberosity
33
What is the action of the anterior part of the deltoid muscle?
Flexes and medially rotates the humerus
34
What is the action of the posterior part of the deltoid muscle?
Extends and laterally rotates the humerus
35
What is the action of the lateral part of the humerus?
Abducts the humerus to shoulder height
36
What is the action of the upper part of the trapezius muscle?
Elevates the scapula/squares the shoulders
37
What is the action of the lower part of the trapezius muscle?
Depresses the scapula
38
What is the action of the middle part of the trapezius muscle?
Retracts the scapula
39
What are the actions of all 3 parts of the trapezius together?
1. Upward rotation of the scapula
| 2. Abduction to ABOVE SHOULDER HEIGHT
40
What is the action of the serratus anterior muscle?
Abduction to above shoulder height and protraction of the scapula
41
What is the innervation of the serratus anterior?
Long thoracic nerve
42
What pathology results from a long thoracic nerve lesion?
"Winged scapula" sign
43
What is the action of the pectoralis major muscle?
Adducts and medially rotates the humerus (protracts the scapula)
44
What is the action of the clavicular head of the pectoralis major?
Flexes extended arm
45
What is the action of both heads (sternal and clavicular head) of the pectoralis major muscle?
Extend flexed arm
46
What is the distal attachment of the pectoralis major muscle?
Lateral lip of the intertubercular groove of the humerus
47
What is the distal attachment of the latissimus dorsi muscle?
Floor of the intertubercular groove of the humerus
48
What is the action of the latissimus dorsi muscle?
Adducts, extends, and medially rotates the humerus (retracts the scapula)
49
What is the apex of the axilla?
At the lateral border of the first rib, between the clavicle and the scapula
50
What is the base of the axilla?
Skin and axillary fascia of the armpit
51
What is the medial boundary of the axilla?
Ribs and intercostal muscles; serratus anterior muscle
52
What is the lateral boundary of the axilla?
Floor of the inter tubercular groove of the humerus
53
What is the anterior boundary of the axilla?
Anterior axillary fold (subclavius, pectoralis major and minor muscles)
54
What is the posterior boundary of the axilla?
Posterior axillary fold (scapula, subscapularis, teres major and latissiums dorsi)
55
At the lateral border of the first rib (apex of the axilla), what does the subclavian artery change its name to?
The axillary artery
56
What branch is present in the first segment (medial to pectoralis minor) of the axillary artery?
Superior thoracic artery
57
What 2 branches is present are present in the second segment of the axillary artery (under the pectoralis minor)?
1. Thoracoacromial artery
| 2. Lateral thoracic artery
58
What are the 3 branches from the third segment (lateral to the pectoralis minor) of the axillary artery?
1. Anterior humeral circumflex artery
2. Posterior humeral circumflex artery
3. Subscapular artery
59
What branch does the circumflex scapular artery arise from?
The sub scapular artery
60
What nerve passes to the posterior scapular region?
Axillary nerve
61
What arteries pass to the posterior scapular region?
1. Posterior humeral circumflex artery
| 2. Circumflex scapular artery
62
What ventral rami serve as the roots for the brachial plexus?
C5-T1
63
What 2 rami form the superior trunk?
C5 and C6
64
What ramus becomes the middle trunk?
C7
65
What 2 rami merge to form the inferior trunk?
C8 and T1
66
What does each trunk in the brachial plexus bifurcate into?
Anterior and posterior divisions
67
What compartment(s) do the 3 anterior divisions transmit axons to?
Anterior (flexor/pronator) compartments of arm and forearm
68
What compartment(s) do the 3 posterior divisions transmit axons to
Posterior (extensor-supinator) muscle compartments of the arm
69
When all 3 posterior divisions merge, what is formed?
The posterior cord
70
What 2 divisions merge to form the lateral cord?
Anterior divisions of superior and middle trunks
71
What does the anterior division of the inferior trunk change its name to?
The medial cord
72
What are the cords named according to?
Their relation to the axillary artery
73
What spinal level (root) does the dorsal scapular nerve arise from?
C5
74
What cord does the lateral pectoral nerve arise from?
Lateral cord
75
What cord does the medial pectoral nerve arise from?
Medial cord
76
What is the name of the medial condyle of the humerus?
Trochlea
77
What is the name of the lateral condyle of the humerus?
Capitulum
78
What are the 3 articulations in a common synovial cavity that make up the elbow joint?
1. Humeroulnar articulation--> true hinge joint (flexion/extension)
2. Humeroradial articulation--> supination/pronation
3. Proximal radioulnar articulation--> supination/pronation
79
What is the pathophysiology of subluxation/dislocation of the radial head (aka Nursemaid's elbow)?
Child is jerked by upper limb. Will refuse to use limb/hold it with the elbow flexed and forearm pronated.
Source of chronic pain is the ANULAR LIGAMENT, which gets pinched between the radial head and the capitulum of the humerus when the limb is SUPINATED.
80
What are the 3 muscles of the anterior compartment of the arm?
Coracobrachialis muscle
Biceps brachii muscle
Brachialis muscle
81
What are the 2 muscles of the posterior compartment of the arm?
Triceps brachii
| Anconeus
82
What innervates the muscles of the ANTERIOR compartment of the arm?
Musculocutaneous nerve
83
What is the action of the biceps brachii at the shoulder joint?
Flexion, abduction, medial rotation of the arm
84
What are the actions of the biceps brachii muscles at the elbow joint?
Supination of the forearm/flexion of the supine forearm
85
What are the actions of the CORACOBRACHIALIS MUSCLE at the SHOULDER JOINT?
Flexes, adducts, and medially rotates the arm
86
What is the action of the BRACHIALIS muscle at the ELBOW joint?
Flexes the forearm
87
Which nerve pierces the coracobrachilias muscle?
Musculocutaneous nerve
88
What is the action of the muscles of the anterior compartment of the arm?
Flexor compartment
89
What is the action of the muscles of the posterior compartment of the arm?
Extensor compartment
90
What is the innervation of the muscles of the posterior muscles of the arm?
Radial nerve
91
What is the proximal attachment of the long head of the biceps brachii?
Supraglenoid tubercle of the scapula
92
What is the proximal attachment of the long head of the triceps brachii?
Infraglenoid tubercle
93
What is the action of the long head of the triceps brachii at the shoulder joint?
Adduction, retroversion of the humerus, helps stabilize the glenohumeral joint
94
What is the action of the triceps brachii at the elbow joint?
Extension of the forearm
95
What is the action of the anconeus muscle?
Assists with extension of the forearm at the elbow joint
96
What are the general functions of the anterior compartment of the forearm?
Flexion of forearm, wrist and digits, and pronation. (the "anti-anatomical position muscles)
97
What are the muscles of the first layer (superficial layer) of the anterior forearm compartment?
1. Pronator teres muscle (pronator)
2. Flexor carpi radialis muscle (wrist flexor/hand abductor)
3. Palmaris longus muscle (optional wrist flexor)
4. Flexor carpi ulnaris muscle (wrist flexor/hand adductor)
98
What is the common flexor tendon?
A common attachment for the pronator teres, palmaris longus, flexor carpi radials & ulnaris muscle to the medial epicondyle of the humerus
99
What innervates the pronator teres muscle?
Median nerve
100
What innervates the flexor carpi radialis?
Median nerve
101
What innervates the palmaris longus (optional)?
Median nerve
102
What innervates the flexor carpi ulnaris muscle?
ULNAR NERVE (EXCEPTION!!)
103
What innervates the brachioradialis muscle?
The radial nerve
104
What is the proximal attachment of the brachioradialis muscle?
Lateral humerus
105
What is the distal attachment of the brachioradialis muscle?
Styloid process of the radius
106
What is the action of the brachioradialis muscle?
Flexion of the forearm
107
What can you find lateral to medial in the cubital fossa?
1. Biceps Tendon
2. Brachial Artery
3. Median Nerve
(TAN for tendon--> artery--> nerve)
108
Where can you feel the brachial artery pulse in the cubital fossa?
Medial to the biceps brachii tendon
109
What one muscle is in the second layer of the anterior compartment of the forearm?
Flexor digitorum superficialis muscle (4 tendons)
110
What is the action of the flexor digitorum superficialis muscle?
Flexes digits 2-5 at the proximal interphalangeal joints
111
What innervates the flexor digitorum superficialis
Meidan nerve
112
What 2 muscles make up the third layer of the anterior forearm compartment?
(L-->M) Flexor pollicus longus, Flexor digitorum profundus
113
What is the action of the flexor pollicis longus muscle?
Flexes pollux at interphalangeal joint
114
What is the innervation of the flexor pollicis longus?
Anterior osseous nerve (branch of median nerve)
115
What is the action of the flexor digitorum profundus?
Radial half: flexes digits 2-3 at DIP joints
Ulnar half: Flexes digits 4-5 at DIP joints
116
What is the innervation of the flexor digitorum profundus muscle?
Radial half: anterior interosseous nerve (branch of the median nerve)
Ulnar half: Ulnar nerve
117
What muscle is in the 4th layer of the anterior forearm compartment?
Pronator quadratus muscle
118
What is the action of the pronator quadratus?
Pronates the forearm
119
What is the innervation of the pronator quadratus?
Anterior osseous nerve (branch of the Median nerve)
120
What is the carpal tunnel flexor retinaculum (transverse carpal ligament)?
Thickened specialization of the ante brachial fascia forming the roof of the carpal tunnel
121
What is the action of the palmaris brevis muscle?
Tenses the palmar aponeurosis (w/ the palmaris longus muscle) especially when the hand is clenched into a fist. Also, protects the ulnar artery and nerve
122
What is the nerve supply to the palmaris brevis?
Superficial branch of the ulnar nerve
123
What is the nerve and blood supply to the supraspinatus and infraspinatus muscles?
The suprascapular nerve and artery
124
What passes OVER the superior transverse scapular ligament?
Suprascapular artery
125
What passes UNDER the superior transverse scapular ligament?
The suprascapular nerve
126
What nerve and artery run together through the quadrangular space?
The axillary nerve and the posterior circumflex artery
127
What artery runs with the radial nerve?
Deep artery of the arm
128
What are the general function sod the posterior compartment of the arm?
Extension (wrist and digits) and supination (the "anatomical position muscles")
129
What muscles make up the first layer of the posterior forearm?
Extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris
130
What 4 muscles attach to the common extensor tendon on the lateral epicondyle of the humerus?
1. Extensor carpi radialis brevis
2. Extensor digitorum
3. extensor digiti minimi
4. Extensor carpi ulnaris
131
What is the action of the extensor carpi radialis longus, extensor carpi radialis brevis, and the extensor carpi ulnaris muscles?
Extension of the wrist
132
What is the action of the extensor digitorum and the extensor digiti minimi?
Extension of the digits.
133
What are the 3 outcropping muscles?
Abductor pollucis longus, extensor pollucis brevis, and extensor pollucis longus
134
What is the clinical significance of the anatomical snuffbox?
Pulse point for the radial artery
135
What is the name of the deep branch of the radial nerve after it pierces the supinator muscle?
The posterior interosseous nerve
136
What forms the roof of the carpal tunnel?
The flexor retinaculum
137
What is the palmar aponeurosis?
Thickened deep fascia of the palm
138
What is Dupuytren's contracture?
Idiopathic progressive thickening and shortening of longitudinal bands of the palmar aponeurosis especially on the medial side. Results in persistent contraction of the digits (usually 4th & 5th) at the metacarpophalangeal and proximal interphalangeal joints.
Usually affects men > 40 yrs.
Tx = surgical resection of palmar aponeurosis
139
Where does the flexor digitorum profundus insert?
DIP joints (splits the flexor digitorum superficialis below the PIP)
140
Where does the flexor digitorum superficialis insert?
PIP joints
141
What causes trigger finger?
Inflammation of the flexor tendon that causes it to get stuck behind one of the tendon sheath when flexed.
142
What innervates the majority of the intrinsic muscles of the hand?
Ulnar nerve
143
Which intrinsic muscles are NOT innervated by the ulnar nerve?
Lumbricals 1 and 2 and the thenar muscles which are innervated by the median nerve or branches of it
144
How many dorsal interossei muscles are there and what is their action?
4; abduction (DAb)
1 for digit 2, 1 for digit 4 and 2 on either side of digit 3
145
What is the nerve supply of the dorsal and palmar interossei muscles?
Deep branch of the ulnar nerve
146
How many Palmar interossei muscles are there and what is their action?
3; 1 for digit 2, 1 for digit 4 and 1 for the digiti minimi
147
What is the nerve supply to lumbricals 1 and 2?
The median nerve
148
What is the nerve supply to lumbricals 3 and 4?
Ulnar nerve
149
The tendons of which muscle serve as the origin for the lumbricals?
Flexor digitorum profundus
150
What innervates the radial half of the flexor digitorum profundus?
Median nerve
151
What innervates the ulnar half of the flexor digitorum profundus?
Ulnar nerve
152
What is the action of the lumbricals?
Flex digits 2-5 at the MCP joints and EXTEND the digits at interphalangeal joints (Z position)
153
What are the 3 muscles of the thenar compartment?
Abductor pollicis brevis muscle
Flexor pollicis brevis muscle
opponens pollicis muscle
154
What nerve supplies the muscles of the thenar compartment?
Recurrent branch of the median nerve
