Muscles of the Upper Limb Flashcards

1
Q

What are the 4 muscles within the pectoral region?

A
  1. Pectoralis major
  2. Pectoralis minor
  3. Subclavius
  4. Serratus anterior
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2
Q

What are the attachments of pectoralis major?

A

Clavicular head:

  • originates from the anterior surface of the medial clavicle

Sternocostal head:

  • originates from the anterior surface of the sternum, the superior 6 costal cartilages and the aponeurosis of the external oblique muscle

Insertion:

  • intertubercular sulcus of humerus
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3
Q

What is the function and innervation of pectoralis major?

A

Function:

  • adducts and medically rotates the upper limb
  • draws the scapula anteroinferiorly
  • clavicular head will flex the upper limb

Innervation:

  • lateral and medial pectoral nerves
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4
Q

What are the attachments, function and innervation of pectoralis minor?

A

Origin:

  • 3rd to 5th ribs

Insertion:

  • coracoid process of the scapula

Function:

  • stabilises the scapula by drawing it anteroinferiorly against the thoracic wall

Innervation:

  • medial pectoral nerve
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5
Q

What are the attachments, function and innervation of serratus anterior?

A

Origin:

  • muscular strips originate from the lateral aspects of ribs 1-8

Insertion:

  • costal surface of medial border of the scapula

Functions:

  • rotates the scapula, allowing the arm to be raised over 90 degrees
  • holds the scapula against the rib cage

Innervation:

  • long thoracic nerve
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6
Q

What are the attachments, function and innervation of subclavius?

A

Origin:

  • junction of the 1st rib and its costal cartilage

Insertion:

  • inferior surface of the middle third of the clavicle

function:

  • Anchors and depresses the clavicle

Innervation:

  • nerve to subclavius
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7
Q

What is the difference between extrinsic and intrinsic muscles of the shoulder?

A

Extrinsic muscles:

  • originate from the torso and attach to the bones of the shoulder (clavicle, scapula or humerus)

Intrinsic muscles:

  • originate from the scapula and/or clavicle and attach to the humerus
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8
Q

What are the 2 superficial extrinsic muscles of the shoulder?

A
  1. Trapezius
  2. Latissimus dorsi
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9
Q

What are the attachments, innervation and actions of trapezius?

A

Origin:

  • skull, nuchal ligament and spinous processes of C7 - T12

Insertion:

  • clavicle, acromion and the scapula spine

Innervation:

  • motor innervation is from the accessory nerve

Actions:

  • upper fibres elevate the scapula and rotate it during abduction of the arm
  • middle fibres retract the scapula
  • lower fibres pull the scapula inferiorly
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10
Q

What are the attachments, innervation and actions of latissimus dorsi?

A

Origin:

  • spinous processes of T7-T12, iliac crest, thoracolumbar fascia and inferior 3 ribs

Insertion:

  • intertubercular sulcus of the humerus

Innervation:

  • thoracodorsal nerve

Actions:

  • extends, adducts and medically rotates the upper limb
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11
Q

What are the 3 deep extrinsic muscles of the back?

A
  1. Levator scapulae
  2. Rhomboid minor
  3. Rhomboid major

These are situated in the upper back, underneath the trapezius

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12
Q

Label the extrinsic muscles of the shoulder

A
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13
Q

What are the attachments, innervation and actions of levator scapulae?

A

Origin:

  • transverse processes of C1-C4 vertebrae

Insertion:

  • medial border of the scapula

Innervation:

  • dorsal scapular nerve

Actions:

  • Elevates the scapula
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14
Q

What are the attachments, innervation and actions of rhomboid major?

A

Origin:

  • spinous processes of T2-T5 vertebrae

Insertion:

  • medial border of scapula, between scapula spine and inferior angle

Innervation:

  • dorsal scapular nerve

Action:

  • retracts and rotates the scapula
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15
Q

What are the attachments, innervation and actions of rhomboid minor?

A

Origin:

  • spinous processes of C7-T1 vertebrae

Insertion:

  • medial border of the scapula, at the level of the spine of the scapula

Innervation:

  • dorsal scapular nerve

​Actions:

  • retracts and rotates the scapula
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16
Q

What are the 6 intrinsic muscles of the shoulder?

A
  1. Deltoid
  2. Teres major

and the 4 rotator cuff muscles:

  1. Supraspinatus
  2. Infraspinatus
  3. Subscapularis
  4. Teres minor
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17
Q

What are the attachments and innervation of deltoid?

A

Origin:

  • lateral third of the clavicle, acromion and spine of scapula

Insertion:

  • deltoid tuberosity on lateral aspect of humerus

Innervation:

  • axillary nerve
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18
Q

What are the actions of the different fibres of the deltoid?

A

Anterior fibres:

  • flexion and medial rotation

Posterior fibres:

  • extension and lateral rotation

Middle fibres:

  • the major abductor of the arm
  • it takes over from supraspinatus (which abducts the first 15 degrees)
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19
Q

What muscle forms the inferior border of the quadrangular space?

A

teres major

this is the gap that the axillary nerve and posterior circumflex humeral artery pass through to reach the posterior scapula region

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20
Q

What are the attachments, innervation and actions of teres major?

A

Origin:

  • posterior surface of the inferior angle of the scapula

Insertion:

  • medial lip of the intertubercular groove of the humerus

innervation:

  • lower subscapular nerve

Actions:

  • adducts the shoulder
  • medially rotates the arm
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21
Q

What muscles are shown here?

A
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22
Q

What is the collective function of the rotator cuff muscles?

Where do they originate and insert?

A

They originate from the scapula and insert onto the humeral head

They “pull” the humeral head into the glenoid fossa

This gives the glenohumeral joint a lot of additional stability

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23
Q

What are the attachments, innervation and actions of supraspinatus?

A

Origin:

  • supraspinous fossa of the scapula

Insertion:

  • greater tubercle of the humerus

Innervation:

  • suprascapular nerve

Actions:

  • abducts the arm 0-15 degrees
  • assists deltoid for 15-90 degrees
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24
Q

What are the attachments, innervation and actions of infraspinatus?

A

Origin:

  • infraspinous fossa of the scapula

Insertion:

  • greater tubercle of the humerus

Innervation:

  • suprascapular nerve

Action:

  • laterally rotates the arm
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25
Q

What are the attachments, innervation and actions of subscapularis?

A

Origin:

  • subscapular fossa of the scapula

Insertion:

  • lesser tubercle of humerus

Innervation:

  • upper and lower subscapular nerves

Actions:

  • medially rotates the arm
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26
Q

What are the attachments, innervation and actions of teres minor?

A

Origin:

  • posterior surface of scapula, adjacent to its lateral border

insertion:

  • greater tubercle of the humerus

Innervation:

  • axillary nerve

Actions:

  • laterally rotates the arm
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27
Q

Label the rotator cuff muscles:

A
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28
Q

What are the 4 muscles of the upper arm?

A

Anterior compartment:

  • brachialis
  • coracobrachialis
  • biceps brachii

Posterior compartment:

  • Triceps brachii
29
Q
A
30
Q

What is the arterial and nervous supply of the anterior compartment of the arm?

A

musculocutaneous nerve

muscular branches of the brachial artery

31
Q

What are the attachments, actions and innervation of biceps brachii?

A

Origins:

  • long head - supraglenoid tubercle of scapula
  • short head - coracoid process of scapula

Insertion:

  • radial tuberosity

Actions:

  • supination of the forearm
  • flexion of the arm at the elbow and at the shoulder

Innervation:

  • musculocutaneous nerve
32
Q

What is the bicipital aponeurosis and how is it formed?

A

as the tendon of biceps brachii enters the forearm, it gives off a connective tissue sheet (bicipital aponeurosis)

this forms the roof of the cubital fossa and blends with the deep fascia of the anterior forearm

33
Q

What are the attachments, function and innervation of coracobrachialis?

A

Origin:

  • coracoid process of scapula

Insertion:

  • It passes through the axilla to attach to the medial side of the humeral shaft, at the level of the deltoid tubercle

Innervation:

  • musculocutaneous nerve

Actions:

  • flexion of the arm at the shoulder
  • weak adduction of the arm
34
Q

What forms the floor of the cubital fossa?

A

brachialis

35
Q

What are the attachments, functions and innervation of brachialis?

A

Origin:

  • medial and lateral surfaces of humeral shaft

Insertion:

  • ulna tuberosity

Function:

  • flexion of the elbow

Innervation:

  • musculocutaneous nerve
  • contributions from the radial nerve
36
Q

Label the anterior compartment arm muscles

A
37
Q

What is meant by “Popeye sign” and what causes it?

A

it is caused by rupture of the biceps tendon

there is a bulge where the muscle belly is upon flexing the elbow

the patient does not notice much weakness in the upper limb due to the actions of brachialis and supinator muscles

38
Q

What is the blood supply to the posterior compartment of the arm?

A

Profunda brachii artery

39
Q

What are the attachments of triceps brachii?

A

Long head:

  • infraglenoid tubercle of the scapula

Lateral head:

  • humerus - superior to the radial groove

Medial head:

  • humerus - inferior to the radial groove

Insertion:

  • olecranon of the ulna
40
Q

What are the actions and innervation of triceps brachii?

A

Actions:

  • extension of the arm at the elbow

Innervation:

  • radial nerve
41
Q

In general, what are the actions of the muscles in the anterior compartment of the forearm?

A

flexion of the wrist and fingers

pronation

42
Q

What are the 4 superficial compartment muscles of the forearm?

Where do they all originate from?

A
  1. Flexor carpi ulnaris
  2. Flexor carpi radialis
  3. Palmaris longus
  4. Pronator teres

They all arise from the medial epicondyle of the humerus

43
Q

What are the attachments, actions and innervation of flexor carpi ulnaris?

A

Origin:

  • medial epicondyle of humerus

Insertion:

  • Pisiform bone

Actions:

  • flexion and adduction of the wrist

Innervation:

  • ulnar nerve
44
Q

What are the attachments, actions and innervation of palmaris longus?

A

Origin:

  • medial epicondyle of humerus

Insertion:

  • flexor retinaculum of the wrist

Actions:

  • flexion of the wrist

Innervation:

  • median nerve
45
Q

What are the attachments, actions and innervation of flexor carpi radialis?

A

Origin:

  • medial epicondyle of humerus

Insertion:

  • base of metacarpals II and III

Actions:

  • flexion and abduction at the wrist

Innervation:

  • median nerve
46
Q

What are the attachments, actions and innervation of pronator teres?

A

Origin:

  • one origin is from the medial epicondyle
  • one origin is from the coronoid process of the ulna

Insertion:

  • attaches laterally to the mid-shaft of the radius

Actions:

  • pronation of the forearm

Innervation:

  • median nerve
47
Q

Label the superficial muscles of the anterior forearm

A
48
Q

What is the muscle in the intermediate compartment of the forearm?

Why is it a good anatomical landmark?

A

Flexor digitorum superficialis

The median nerve and the ulnar artery pass between its two heads, and then travel posteriorly

49
Q

What are the attachments of flexor digitorum superficialis?

A

Origin:

  • one head originates from the medial epicondyle
  • one head originates from the radius

Insertion:

  • the muscle splits into 4 tendons, which travel through the carpal tunnel
  • they attach to the middle phalanges of the 4 fingers
50
Q

What are the actions and innervation of flexor digitorum superficialis?

A

Actions:

  • flexes metacarpophalangeal joints and proximal interphalangeal joints of 4 fingers
  • flexes the wrist

Innervation:

  • median nerve
51
Q

What are the 3 muscles in the deep compartment of the forearm?

A
  1. Flexor digitorum profundus
  2. Flexor pollicis longus
  3. Pronator quadratus
52
Q

What are the attachments of flexor digitorum profundus?

A

Origin:

  • ulna and associated interosseous membrane

Insertion:

  • at the wrist, it splits into 4 tendons that pass through the carpal tunnel
  • they attach to the distal phalanges of the 4 fingers
53
Q

What are the actions and innervation of flexor digitorum profundus?

A

Actions:

  • it is the only muscle that can flex the distal interphalangeal joints of the fingers
  • flexes metacarpophalangeal joints
  • flexes the wrist

Innervation:

  • Medial half - ulnar nerve
  • lateral half - anterior interosseous branch of the median nerve
54
Q

What are the attachments, actions and innervation of flexor pollicis longus?

A

Origin:

  • anterior surface of radius and interosseous membrane

Insertion:

  • base of distal phalanx of the thumb

Actions:

  • flexes interphalangeal joint and metacarpophalangeal joint of the thumb

Innervation:

  • anterior interosseous branch of the median nerve
55
Q

What are the attachments, innervation and actions of pronator quadratus?

A

Origin:

  • anterior surface of the ulna

Insertion:

  • anterior surface of the radius

Actions:

  • pronates the forearm

Innervation:

  • anterior interosseous branch of the median nerve
56
Q

Label the muscles of the deep compartment of the forearm

A
57
Q

Label the prosection image

A
58
Q

Label the prosection images

A
59
Q

Label the prosection image

A
60
Q

What are the general functions of the posterior compartment forearm muscles?

What is their innervation?

A

they extend the wrist and fingers

they are all innervated by the radial nerve

61
Q

What superficial posterior compartment muscles share a common tendinous origin?

A
  1. Extensor carpi radialis brevis
  2. Extensor digitorum
  3. Extensor carpi ulnaris
  4. Extensor digiti minimi

They share a common tendinous origin at the lateral epicondyle

62
Q

Why is brachioradialis called a “paradoxical muscle”?

A

Its origin and innervation are characteristic of an extensor muscle, but it is actually a flexor at the elbow

63
Q

What are the attachments, actions and innervation of brachioradialis?

A

Origin:

  • proximal aspect of lateral supracondylar ridge of humerus

Insertion:

  • distal end of the radius, just before radial styloid process

Actions:

  • flexes the elbow

Innervation:

  • radial nerve
64
Q

Label the muscles in the superficial layer of the posterior forearm

A
65
Q

What are the attachments, actions and innervation of extensor carpi radialis longus and extensor carpi radialis brevis?

A

Origin:

  • ECRL - supracondylar ridge
  • ECRB - lateral epicondyle

Insertion:

  • metacarpal bones II and III

Actions:

  • extends and abducts the wrist

Innervation:

  • radial nerve
66
Q

What are the attachments, actions and innervation of extensor digitorum?

A

Origin:

  • lateral epicondyle

Insertion:

  • the tendon continues into the distal part of the forearm and splits into four
  • it inserts into the extensor hood of each finger

Actions:

  • extends medial four fingers at the MCP and IP joints

Innervation:

  • Deep branch of radial nerve
67
Q

What are the attachments, actions and innervation of extensor digiti minimi?

A

Origin:

  • lateral epicondyle of humerus

Insertion:

  • it attaches, with the extensor digitorum tendon, into the extensor hood of the little finger

Actions:

  • extends the little finger
  • contributes to extension at the wrist

Innervation:

  • deep branch of the radial nerve
68
Q

What are the attachments, actions and innervation of extensor carpi ulnaris?

A

Origin:

  • lateral epicondyle of the humerus

Insertion:

  • base of metacarpal V

Actions:

  • extension and adduction of the wrist

Innervation:

  • deep branch of the radial nerve
69
Q

What are the attachments, actions and innervation of anconeus?

A

Origin:

  • lateral epicondyle

Insertion:

  • posterior and lateral part of the olecranon

Actions:

  • extends and stabilises the elbow joint
  • abducts the ulna during pronation of the forearm

Innervation:

  • radial nerve