Lecture 10: Upper Extremity Myology

Question 1

Pectoralis Major M.

What are the attachments?

Answer 1

Origin: Claviclular Head, Sheath of Rectus Abdominis, Clavical, Sternum

Insertion: Lateral Edge of the Intertubercular Groove of Humerus

(covers the long head of Biceps Brachii M)

Question 2

Pectoralis Major M.

What are the major actions?

Answer 2

1. Adduct and Medially Rotate Humerus
2. Protract and Depress Scapula
3. Clavicular Head: Flex Humerus
4. Sternocostal Head: Extend Humerus from flexed state

Question 3

Pectoralis Major M.

What is the innervation and blod supply?

Answer 3

Innervation: Lateral and Medial Pectoral Nerve

Blood Supply: Pectoral Branch of the Thoracoacromial Trunk

Question 4

Pectoralis Minor M.

What are the attachments?

Answer 4

Origin: Medial aspect of Ribs 3-5

Insertion: Coracoid Process of the Scapula

Question 5

Pectoralis Minor M.

What is the action?

Answer 5

Stabilizes the Scapula by holding it to thoracic wall

Question 6

Pectoralis Minor M.

What is the innervation and blood supply?

Answer 6

Innervation: Medial Pectoral Nerve

(It gets pity innervated on the way to the Pectoralis Major M.)

Blood Supply: Pectoral Branch of the Throacoacromial Trunk

Question 7

Subclavius M.

What are the attachments?

Answer 7

Origin: Upper border of 1st rib and 1st Costal Cartilage

Insertion: Inferior aspect of the Clavicle

Question 8

Subclavius M.

What is the Action?

Answer 8

Depresses the Clavicle

Question 9

Subclavius M.

What is the innervation and blood supply?

Answer 9

Innervation: Nerve to the Subclavius

Blood Supply: Clavicular Branch of the Thoracoacromial Trunk

Question 10

Serratus Anterior M.

What are the attachments?

Answer 10

Origin: Lateral external surface of Ribs 1-8

Insertion: Anterior surface of medial border of scapula

Question 11

Serratus Anterior M.

What are the actions?

Answer 11

1. Protraction of the Scapula
   * (Boxer’s Serratus Anterior Muscles are buff for this reason)*
2. Superior Rotation of the Glenoid Cavity
   * (Pulls the medial border down towards the ribs - lateral end goes up)*
3. Stabalizes the Scapula by pulling it to the Thoracic Wall

Question 12

Serratus Anterior M.

What is the innervation and blood supply?

Answer 12

Innervation: Long Thoracic Nerve

Blood Supply: Lateral Thoracic Artery

Question 13

If the Serratus Anterior or Long Thoracic Nerve is damaged, what can it cause and what motion does this prevent?

Answer 13

“Winging” of the Scapula

• Scapula is no longer Stabalized against the Thoracic Wall
• Abduction of the Upper Extremity beyond the Horizontal Position

Question 14

Deltoid Muscle

What are the Attachments?

Answer 14

Origin: Lateral Clavicle, Scapular Spine, and Acromion

Insertion: Deltoid Tuberosity of the Humerus

Question 15

Deltoid Muscle

What are the actions?

Answer 15

Anterior Part: Flex and Medial Rotation of the Humerus

Middle Part/Whole Muscle: Abduction of the Humerus

Posterior Part: Extension of the Shoulder and Lateral Rotation of the Humerus

Question 16

Deltoid Muscle

What is the innervation and blood supply?

Answer 16

Innervation: Axillary Nerve

Blood Supply: Posterior Circumflex Humeral Artery (main)

Deltoid Branch of Thoracoacromial Artery

Question 17

Subscapularis Muscle

What are the attachments?

Answer 17

Orign: Medial Aspect Subscapular Fossa

Insertion: Lesser Tubercle of the Humerus

Question 18

Subscapularis Muscle

What are its actions?

Answer 18

1. Medial Rotation of the Humerus
2. Adduction of the Humerus
3. Holds humeral head in glenoid cavity

Question 19

For the Subscapularis M.

What is the innervation and blood supply?

Answer 19

Innervation: Upper and Lower Subscapular Nerve

Blood Supply: Subscapular Artery

Question 20

Supraspinatus Muscle

What are the attachments?

Answer 20

Origin: Supraspinous Fossa of the Scapula

Insertion: Greater Humeral Tubercle (running over the superior-most part of the Humerus)

Question 21

Supraspinatus Muscle

What is the action?

Answer 21

1. Abduction of the Humerus (along with deltoids)
2. Holds Humeral Head in Glenoid Cavity

Question 22

Supraspinatus Muscle

What is the innervation and blood supply?

Answer 22

Innervation: Suprascapular Nerve

Blood Supply: Suprascapular Artery

Question 23

Infraspinatus Muscle

What are the attachments?

Answer 23

Origin: Infraspinous Fossa of Scapula

Insertion: Greater Tubercle of the Humerus

Question 24

Infraspinatus Muscle

What is its action?

Answer 24

1. Lateral Rotation of the Humerus
2. Holds Humeral Head in Glenoid Cavity

Question 25

**Infraspinatus Musle** What is the innervation and blood supply?

Answer 25

**Innervation:** Suprascapular Nerve **Blood Supply:** Suprascapular Artery and Circumflex Scapular Artery *(The Circumflex Scapular Artery comes _around_ the lateral border of the scapula and heads superiorly and medially)*

Question 26

**Teres Minor Muscle** What are the attachments?

Answer 26

**Origin:** Middle Part of Lateral Border of Scapula **Insertion:** Greater Tubercle of Humerus

Question 27

**Teres Minor Muscle** What are its actions?

Answer 27

1. Laterally Rotates Humerus 2. Holds Humeral Head in Glenoid Cavity

Question 28

**Teres Minor Muscle** What is the innervation and blood supply?

Answer 28

**Nerve****:** Axillary Nerve **Blood Supply**: Circumflex Scapular Artery and Subscapular Artery

Question 29

**Teres Major Muscle** What are the attachments?

Answer 29

**Origin**: Posterior aspect of Inferior Angle of the Scapula **Insertion:** Medial edge of Intertubercular groove (_Front_ of the Humerus)

Question 30

**Teres Major Muscle** What are the actions?

Answer 30

1. Medial rotation of the Humerus (Pulls the front of the Humerus medially) 2. Adduction of the Humerus

Question 31

**Teres Major Muscle** What is the innervation and blood supply?

Answer 31

**Innervation:** Lower Subscapular Nerve **Blood Supply:** Subscapular Artery and Circumflex Scapular Artery

Question 32

What are the four rotator cuff muscles?

Answer 32

Supraspinatus M. Infraspinatus M. Teres Minor M. Subscapularis M.

Question 33

**Triangular Space** What muscles make up the border? What can be found within?

Answer 33

**Borders**: Teres Major, Teres Minor, Long Head of Triceps Brachii M. **Contains**: Circumflex Scapular Artery and Vein

Question 34

**Quadrangular** **Space** What muscles make up the four borders? What can be found within?

Answer 34

**Borders**: Long and Lateral Head of the Triceps Brachii M., Teres Major M. Teres Minor M. **Contains**: Axillary Artery, Posterior Circumflex Humeral Artery, Posterior Circumflex Humeral Vein *(Contents are headed to the Deltoid Muscle, so if you remember the Deltoid M.'s nerve and artery, there you go)*

Question 35

**Triangular Interval** What muscles make up its three borders? What does it contain?

Answer 35

**Borders**: Long and Lateral Head of the Triceps Brachii, Teres Major M. **Contains**: Deep Brachial Artery and Vein, Radial Nerve

Question 36

What part of the Biceps Brachii M. covers the Pronator Teres M.?

Answer 36

The Bicipital Aponeurosis

Question 37

**Biceps Brachii Muscle** What are the attachments?

Answer 37

**Origin:** _Long Head:_ Supraglenoid Tubercle of Scapula _Short Head:_ Coracoid Process of Scapula **Insertion:** Radial Tuberosity and Antebrachial Fascia (bicipital aponeurosis) *The Biceps Brachii skips the Humerus entirely*

Question 38

**Biceps Brachii Muscle** What are the actions?

Answer 38

1. Flexes humerus and supinated forearm 2. Supinates forearm 3. _Short Head_ resists dislocation of shoulder * Remember that these Muscles Flex/Extend the Joints they cross*

Question 39

**Biceps Brachii Muscle** What is the innervation and blood supply?

Answer 39

**Innervation:** Musculocutaneous Nerve **Blood Supply:** Brachial Artery

Question 40

**Coracobrachialis Muscle** What are the attachments?

Answer 40

**Origin:** Coracoid Process of Scapula **Insertion:** Medial Aspect of the Humeral Body

Question 41

**Coracobrachialis Muscle** What are the actions?

Answer 41

1. Flexion of Shoulder 2. Adduction of Shoulder

Question 42

**Coracobrachialis Muscle** What is the innervation and blood supply?

Answer 42

**Innervation:** Musculocutaneous Nerve **Blood Supply:** Brachial Artery

Question 43

**Brachialis Muscle** What are the attachments?

Answer 43

**Origin:** Distal half of anterior aspect of Humerus **Insertion:** Ulnar Tuberosity and Coranoid Process

Question 44

**Brachialis Muscle** What is the action?

Answer 44

Flexion of the Forearm (elbow joint) ## Footnote *The Bicep cannot flex a pronated Elbow. The Brachialis does that.*

Question 45

**Brachialis Muscle** What is the innervation and blood supply?

Answer 45

**Innervation:** Musculocutaneous Nerve **Blood Supply:** Radial Recurrent Artery

Question 46

**Triceps Brachii Muscle** Where are the attachments?

Answer 46

**Origin:** _Long Head:_ Infraglenoid Tubercle of Scaupla _Lateral Head:_ Posterior aspect of Humerus (*superior* to radial groove) _Medial Head:_ Posterior aspect of Humerus (*inferior* to radial groove) **Insertion:** Olecranon of Ulna and Antebrachial Fascia

Question 47

Triceps Brachii Muscle What is the action?

Answer 47

1. Extend the Forearm 2. Long Head resists dislocation of shoulder

Question 48

**Triceps Brachii Muscle** What is the innervation and blood supply?

Answer 48

**Innervation:** Radial Nerve **Blood Supply:** Deep Brachial Artery

Question 49

**Anconeus Muscle** What are the attachments?

Answer 49

**Origin:** Lateral Humeral Epicondyle **Insertion:** lateral aspect of Olecranon *(Even though it attaches to the Lateral Humeral Epicondyle like an extensor and exists entirely in the forearm, it's considered a posterior compartment Brachial Muscle for this class. This may be because some people consider it to be a continuation of Triceps Brachii M.)*

Question 50

**Anconeus Muscle** What is the action?

Answer 50

1. Extends the forearm (elbow) 2. Stabilizes elbow joint

Question 51

**Anconeus Muscle** What is the innervation and blood supply?

Answer 51

**Innervation:** Radial Nerve **Blood Supply:** Deep Brachial Artery

Question 52

**Pronator Teres Muscle** What are the attachements?

Answer 52

**Origin:** Humeral Head: Medial Epicondyle of Humerus Ulnar Head: Coranoid Process of Ulna **Insertion:** Lateral aspect of the Radius

Question 53

**Pronator Teres Muscle** What is the action?

Answer 53

Pronate and Flex forearm (Elbow)

Question 54

**Pronator Teres Muscle** What is the innervation and blood supply?

Answer 54

**Innervation:** Median Nerve **Blood Supply:** Ulnar Artery and Radial Artery

Question 55

**Flexor Carpi Radialis Muscle** What are the attachments?

Answer 55

**Origin:** Medial Humeral Epicondyle **Insertion:** Base of 2^nd Metacarpal on palmar aspect

Question 56

**Flexor Carpi Radialis Muscle** What are the actions?

Answer 56

1. Flex forearm and hand 2. Abduct the Wrist

Question 57

**Flexor Carpi Radialis Muslce** What is the innervation and blood supply?

Answer 57

**Innervation:** Median Nerve **Blood Supply:** Ulnar Artery

Question 58

**Palmaris Longus Muscle** What are the attachments?

Answer 58

**Origin:** Medial Humeral Epicondyle **Insertion:** Palmar Aponeurosis and Flexor Retinaculum

Question 59

**Palmaris Longus Muscle** What is the action?

Answer 59

1. Flexes forearm and hand 2. Tenses Palmar Aponeurosis

Question 60

**Palmaris Longus Muscle** What is the innervation and blood supply?

Answer 60

**Innervation:** Median Nerve **Blood Supply:** Ulnar Artery

Question 61

**Flexor Carpi Ulnaris Muscle** What are the attachements?

Answer 61

**Origin:** Humeral Head: Medial Humeral Epicondyle Ulnar Head: Olecranon and Posterior Ulna **Insertion:** Pisiform Bone, Hook of the Hamate, Base of 5th Metacarpal (palmar aspect) *(Inserts everywhere in the medial Wrist)*

Question 62

**Flexor Carpi Ulnaris Muscle** What are the actions?

Answer 62

1. Flexion of forearm and hand at wrist 2. Adduction of hand at wrist

Question 63

**Flexor Carpi Ulnaris Muscle** What is the innervation and blood supply?

Answer 63

**Innervation:** Ulnar Nerve **Blood Supply:** Ulnar Artery

Question 64

**Flexor Digitorum Superficialis Muscle** What are the attachements?

Answer 64

**Onset:** Humeroulnar Head: Medial Humeral Epicondyle Coronoid Process of the Ulna Radial Head: Superior portion of the anterior Radius **Insertion:** _Intermediate Phalanges_ of digits 2-5 at metacarpophlangeal and proximal interphalangeal joints (anterior aspect) *Insertion is Bifid*

Question 65

**Flexor Digitorum Superficialis Muscle** What are the actions?

Answer 65

Flexion of the joints it crosses -Flexes forearm, hand at wrist, proximal and intermediate phalanges of digits 2-5

Question 66

**Flexor Digitorum Superficialis Muscle** What is the innervation and blood supply?

Answer 66

**Innervation:** Median Nerve **Blood Supply:** Ulnar Artery

Question 67

**Flexor Digitorum Profundus Muscle** What are the attachments?

Answer 67

**Origin:** Proximal Ulna and Interosseous Membrane **Insertion:** Palmar Aspect of _Distal Phalanges_ of Digits 2-5 *Tendon passes through bifid of superficialis*

Question 68

**Flexor Digitorum Profundus Muscle** What are the actions?

Answer 68

Flex hand at wrist, all phalanges of digits 2-5 at all joints ## Footnote *Does not flex forearm (elbow)*

Question 69

**Flexor Digitorum Profundus Muscle** What is the innervation and bood supply?

Answer 69

**Innervation:** *Medial Portion:* Ulnar Nerve * Lateral portion:* Median Nerve * Its medial portion is directly underneath the ulnar nerve, so it kind of gets accidentally innervated.* **Blood Supply:** Ulnar Artery and Anterior Interosseous Artery

Question 70

**Flexor Pollicis Longus Muscle** What are the attachments?

Answer 70

**Origin:** Radius and Interosseous Membrane **Insertion:** Palmar aspect of the base of Distal Phalanx of the Thumb

Question 71

For the Flexor Pollicis Longus Muscle What is the action?

Answer 71

1. Flexes hand and thumb 2. _Abduct_ thumb at 1st carpometacarpal joint

Question 72

**Flexor Pollicus Longus Muscle** What is the innervation and blood supply?

Answer 72

**Innervation:** Anterior Interosseous Nerve (branch of the Median Nerve) **Blood Supply:** Anterior Interosseous Artery

Question 73

**Pronator Quadratus Muscle** What are the attachments?

Answer 73

**Origin:** Anterior Aspect of Distal Ulna **Insertion:** Anterior Aspect of Distal Radius

Question 74

**Pronator Quadratus Muscle** What is the action?

Answer 74

1. Pronation of forearm 2. Holds the Ulna and Radius together

Question 75

**Pronator Quadratus Muscle** What is the innervation and blood supply?

Answer 75

**Innervation:** Anterior Interosseous Nerve **Blood Supply:** Anterior Interosseous Artery

Question 76

The **radial nerve** innervates what two superficial antebrachial extensors? (*before it changes names*)

Answer 76

1. Brachioradialis M. 2. Extensor Carpi Radialis Longus M.

Question 77

The **deep radial nerve** innervates what two antebrachial extensors?

Answer 77

1. Extensor Carpi Radialis Brevis M. 2. Supinator M.

Question 78

The Posterior Interosseous Nerve innervates what three antebrachial extensors?

Answer 78

1. Extensor Digitorum M. 2. Extensor Digiti Minimi M. 3. Extensor Carpi Ulnaris M.

Question 79

**Brachioradialis Muscle** What are the attachments?

Answer 79

**Origin:** Lateral Humeral Supracondylar Ridge **Insertion:** Lateral aspect of distal Radius

Question 80

**Brachioradialis Muscle** What is the action?

Answer 80

1. _Flexes_ forearm (Elbow) when the Arm is "Mid-Pronated" (When the thumb is facing up)

Question 81

**Brachioradialis Muscle** What is the innervation and blood supply?

Answer 81

**Innervation:** Radial Nerve **Blood Supply:** Radial Reccurent Artery

Question 82

**Extensor Carpi Radialis Longus Muscle** What are the attachments?

Answer 82

**Origin:** Lateral Humeral Supracondylar Ridge **Insertion:** Dorsal aspect of the base of 2^nd Metacarpal Digit

Question 83

**Extensor Carpi Radialis Longus Muscle** What is the action?

Answer 83

1. Extension hand at wrist 2. Abduct hand at wrist (during fist clenching)

Question 84

**Extensor Carpi Radialis Longus Muscle** What is the innervation and blood supply?

Answer 84

**Innervation:** Radial Nerve **Blood Supply:** Radial Artery

Question 85

**Extensor Carpi Radialis Brevis Muscle** What are the attachments?

Answer 85

**Origin:** Lateral Humeral Epicondyle **Insertion:** Dorsal Aspect of 3^rd Metacarpal Base

Question 86

**Extensor Carpi Radialis Brevis Muscle** What are the actions?

Answer 86

1. Extension of hand at wrist 2. _Abduction_ of hand at wrist

Question 87

**Extensor Carpi Radialis Brevis Muscle** What is the innervation and blood supply?

Answer 87

**Innervation:** Deep Radial Nerve **Blood Supply:** Radial Artery

Question 88

**Extensor Digitorum Muscle** What are the attachments?

Answer 88

**Onset:** Lateral Humeral Epicondyle **Insertion:** Extensor Expansions of Digits 2-5

Question 89

**Extensor Digitorum Muscle** What is the action?

Answer 89

Extension of hand at wrist and 2^nd-5^th phalanges at every joint

Question 90

**Extensor Digitorum Muscle** What is the innervation and blood supply?

Answer 90

**Innervation:** Posterior Interossious Nerve *(comes from the Radial Nerve)* **Blood Supply:** Posterior Interossious Artery

Question 91

When does the Deep Radial Nerve become the Posterior Interosseous Nerve?

Answer 91

After it ducks under the Supinator and emerges again

Question 92

**Extensor Digiti Minimi Muscle** What are the attachments?

Answer 92

**Onset:** Lateral Humeral Epicondyle **Insertion:** Extensor Expansion of Digit 5

Question 93

**Extensor Digiti Minimi Muscle** What is the action?

Answer 93

Extends 5^th Digit at all joints

Question 94

**Extensor Digiti Minimi Muscle** What is the innervation and blood supply?

Answer 94

**Innervation:** Posterior Interosseous Nerve **Blood Supply:** Posterior Interosseous Artery

Question 95

**Extensor Carpi Ulnaris Muscle** What are the attachements?

Answer 95

**Origin:** Lateral Humeral Epicondyle **Insertion:** Dorsal aspect of 5th Metacarpal Base

Question 96

**Extensor Carpi Ulnaris Muscle** What is the action?

Answer 96

1. Extension of hand at wrist 2. _Adduction_ of hand at wrist

Question 97

**Extensor Carpi Ulnaris Muscle** What is the innervation and blood supply?

Answer 97

**Innervation:** Posterior Interosseous Nerve *This is tough because it has Ulnar in the name, but remember that exception is only true on the Flexor side. ALL of the Extensors of the arm are innervated by the Radial Nerve, or a branch thereof.* **Blood Supply:** _Ulnar Artery_

Question 98

Repetitive use of the superficial extensor muscles of the forearm can cause what?

Answer 98

Elbow Tendinitis or "Tennis Elbow" -pain over lateral epicondyle and down posterior forearm

Question 99

**Supinator Muscle** What are the Attachments?

Answer 99

**Origin:** Lateral Humeral Epicondyle, Radial Collateral Ligament of the Elbow, Annular Ligament, Supinator Crest and Fossa of the Ulna **Insertion:** Proximal aspect of Radius

Question 100

**Supinator Muscle** What is the aciton?

Answer 100

Supinate Forearm

Question 101

**Supinator Muscle** What is the innervation and blood supply?

Answer 101

**Innervation:** Deep Radial Nerve **Blood Supply:** Radial Recurrent Artery

Question 102

**Extensor Indicis Muscle** What are the attachments?

Answer 102

**Origin:** Posterior aspect of Distal Ulna and Interosseous Membrane **Insertion:** Extensor Expansion of Digit 2

Question 103

**Extensor Indicis Muscle** What is the action?

Answer 103

Extend hand at wrist and extend 2nd Digit (Index Finger)

Question 104

**Extensor Indicis Muscle** What is the innervation and blood supply?

Answer 104

**Innervation:** Posterior Interosseous Nerve **Blood Supply:** Posterior Interosseous Artery

Question 105

**Abductor Pollicis Longus Muscle** What are the attachements?

Answer 105

**Origin:** Posterior aspect of proximal Ulna, Radius, Interosseous Membrane **Insertion:** Base of 1st Digit Metacarpal

Question 106

**Abductor Pollicis Longus Muscle** What is the action?

Answer 106

Abduction of hand at wrist and Thumb at carpometacarpal joint

Question 107

**Abductor Pollicis Longus Muscle** What is the innervation and blood supply?

Answer 107

**Innervation:** Posterior Interosseous Nerve (This is an outcropping muscle, but they are innervated like the extensors) **Blood Supply:** Posterior Interosseous Artery

Question 108

**Extensor Pollicis Longus Muscle** What are the attachments? What is interesting about the Tendon for this Muscle?

Answer 108

**Origin:** Posterior aspect of Ulna and Interosseous Membrane **Insertion:** Dorsal aspect Base of the **Distal Phalanx** of the thumb. *Extensor Pollicis Longus M. goes to the Distal Phalanx, Extensor Pollicis Brevis M. goes to the Proximal Phalanx* The Tendon wraps around the **Dorsal Radial Tubercle** and uses it as a pulley.

Question 109

**Extensor Pollicis Longus Muscle** What is the action?

Answer 109

1. Extension of the Thumb at all joints 2. _Abduction_ of the Wrist

Question 110

**Extensor Pollicis Longus Muscle** What is the innervation and blood supply?

Answer 110

**Innervation:** Posterior Interosseous Nerve **Blood Supply:** Posterior Interosseous Artery

Question 111

**Extensor Pollicis Brevis Muscle** What are the attachments?

Answer 111

**Origin:** Posterior aspect of Radius and Interosseous Membrane **Insertion:** Dorsal aspect of the base of the Proximal Phalanx of Thumb

Question 112

**Extensor Pollicis Brevis Muscle** What are the actions?

Answer 112

1. Extends Thumb 2. _Abducts_ hand at wrist

Question 113

**Extensor Pollicis Brevis Muscle** What is the innervation and blood supplt?

Answer 113

**Innervation:** Posterior Interosseous Nerve **Blood Supply:** Posterior Interosseous Artery

Question 114

What are the borders for the Anatomical Snuff Box? What are its contents?

Answer 114

**Lateral Border**: Extensor Pollicis Brevis Tendon and Abductor Pollicis Longus **Medial Border**: Extensor Pollicis Longus Tendon *The shorter Muscle has to be closer to the Thumb (lateral side)* **Contents:** Radial Artery (deep tendons) and Superficial Radial Nerve

Question 115

**Abductor Pollicis Brevis Muscle** What are the attachments?

Answer 115

**Origin:** Tubercles of Scaphoid and Trapezium bones and Flexor Retinaculum **Insertion:** Lateral aspect of Base of the Proximal Phalanx of the Thumb

Question 116

**Abductor Pollicis Brevis Muscle** What is the action?

Answer 116

1. Abducts the Thumb 2. Helps with Opposition

Question 117

**Abductor Pollicis Brevis Muscle** What is the innervation and blood supply?

Answer 117

**Innervation:** Recurrant Branch of the Median Nerve **Blood Supply:** Radial Artery

Question 118

**Opponens Pollicis Muscle** What are the attachments?

Answer 118

**Origin:** Tubercles of Scaphoid and Trapezium bones and Flexor Retinaculum **Insertion:** Lateral Aspect of 1^st Metacarpal

Question 119

**Opponens Pollicis Muscle** What is the action?

Answer 119

Opposition of the Thumb

Question 120

**Opponens Pollicis Muscle** What is the innervation and blood supply?

Answer 120

**Innervation:** Recurrent Branch of the Median Nerve *This is the O in 1/2 LOAF 1/2* **Blood Supply:** Radial Artery

Question 121

**Flexor Pollicis Brevis Muscle** What are the attachments?

Answer 121

**Origin:** Tubercles of Scaphoid and Trapezium bones and Flexor Retinaculum **Insertion:** Lateral aspect of thumb

Question 122

**Flexor Pollicis Brevis Muscle** What is the action?

Answer 122

Flexes the _Metacarpal_ and the _Proximal Phalanx_ of the Thumb

Question 123

**Flexor Pollicis Brevis Muscle** What is the innervation and blood supply?

Answer 123

**Innervation:** _Superficial Head:_ Recurrent Branch of the Median Nerve _Deep Head:_ Deep Ulnar Nerve *This is the "F 1/2" in "1/2 LOAF 1/2"* **Blood Supply:** Radial Artery

Question 124

**Adductor Pollicis Muscle** What are the attachments?

Answer 124

**Origin:** _Oblique Head:_ Capitate and Bases 2^nd and 3^rd Metacarpal bones _Transverse Head:_ Palmar aspect of Body of the 3^rd Metacarpal bone **Insertion:** Medial aspect of proximal phalanx of thumb

Question 125

**Adductor Pollicis Muscle** What is the action?

Answer 125

Adduction of thumb

Question 126

**Adductor Pollicis Muscle** What is the innervation and blood supply?

Answer 126

**Innervation:** Deep Ulnar Nerve **Blood Supply:** Deep Palmar Anterior Arch

Question 127

How do the thenar muscles look like together?

Answer 127

Question 128

A superficial injury to the Thenar Eminence can damage what nerve? What does this impede?

Answer 128

Recurrent Branch of the Median Nerve Many of the Thumb Muscles

Question 129

**Abductor Digiti Minimi Muscle** What are the attachments?

Answer 129

**Origin:** Pisiform Bone **Insertion:** Medial aspect of the base of the Proximal Phalanx of the 5th Digit

Question 130

**Abductor Digiti Minimi Muscle** What is the action?

Answer 130

Abduction of the pinkie finger

Question 131

**Abductor Digiti Minimi Muscle** What is the innervation and bood supply?

Answer 131

**Innervation:** Deep Ulnar Nerve **Blood Supply:** Ulnar Artery

Question 132

**Flexor Digiti Minimi Muscle** What are the attachments?

Answer 132

**Origin:** Hook of the Hamate and Flexor Retinaculum **Insertion:** Medial aspect of the Base of the Proximal Phalanx of the 5th Digit

Question 133

**Flexor Digiti Minimi Muscle** What is the action?

Answer 133

Flexes the 5th Digit

Question 134

**Flexor Digiti Minimi Muscle** What is the innervation and blood supply?

Answer 134

**Innervation:** Deep Ulnar Nerve **Blood Supply:** Ulnar Artery

Question 135

**Opponens Digiti Minimi Muscle** What is the attachment?

Answer 135

**Origin:** Hook of the Hamate and Flexor Retinaculum **Insertion:** Middle of the 5th Metacarpal

Question 136

**Opponens Digiti Minimi Muscle** What is the action?

Answer 136

Opposition of the 5th Digit

Question 137

**Opponens Digiti Minimi Muscle** What is the innervation and blood supply?

Answer 137

**Innervation:** Deep Ulnar Nerve **Blood Supply:** Ulnar Artery

Question 138

What do hypothenar muscles look like together?

Answer 138

Question 139

**1^st and 2^nd Lumbrical Muscles** What are their attachments?

Answer 139

**Origin:** Lateral side of the lateral two _Flexor Digitorum Profundus Tendons_ **Insertion:** Radial aspect of Extensor Expansion of the 2^nd and 3^rd digits *He made a big deal about these originating at a tendon in class*

Question 140

**1^st and 2^nd Lumbrical Muscles** What is their action?

Answer 140

1. Flex proximal phalanges of index and middle fingers at metacarpophalangeal joint 2. Extend intermediate and distal phalanges of index and middle fingers by tightening extensor expansion

Question 141

**1^st and 2^nd Lumbrical Muscles** What are their innervations and blood supply?

Answer 141

**Innervation:** Recurrant Branch of the Median Nerve **Blood Supply:** Superficial Palmar Arch, Common Palmar Digital aa., Deep Palmar Arch, Dorsal Digital aa.

Question 142

**3^rd and 4^th Lumbrical Muscles** What are their attachments?

Answer 142

**Origin:** Between medial three _Flexor Digitorum Profundus Tendons_ (bipennate) **Insertion:** Radial aspect of Extensor Expansion of the 4^th and 5^th digits

Question 143

**3^rd and 4^th Lumbrical Muscles** What is their action?

Answer 143

1. Flex proximal phalanges of ring and pinkie fingers at metacarpophalangeal joint 2. Extend intermediate and distal phalanges of ring and pinkie fingers by tightening extensor expansion

Question 144

**3^rd and 4^th Lumbrical Muscles** What are their innervations and blood supply?

Answer 144

**Innervation:** Deep Ulnar Nerve **Blood Supply:** Superficial Palmar Arch, Common Palmar Digital aa., Deep Palmar Arch, Dorsal Digital aa.

Question 145

**Dorsal Interosseous Muscles** What are their attachments? How many of these do we have?

Answer 145

**Origin:** Adjacent sides of two metacarpals (bipennete) **Insertion:** Bases of proximal phlanges and extensor expansion of digits 2-4 Go between a given digit, and the digit closer to the middle finger (*Eg. 1st Digit to 2nd Digit, but 5th Digit to 4th Digit)* **Total: 4 Dorsal Inerosseous Muscles** - 2^nd and 4^th digits have one each - 3^rd digit abducts both ways and has two. * The thumb and pinky have their own abductors*

Question 146

**Dorsal Interosseous Muscles** What is their action?

Answer 146

Abduction of the 2^nd-4^th digits ## Footnote *DAB Dorsals ABduct*

Question 147

**Dorsal Interosseous Muscles** What is the innervation?

Answer 147

**Innervation:** Deep Ulnar Nerve **Blood Supply:** Dorsal and Palmar Metacarpal aa.

Question 148

**Palmar Interosseous Muscles** What are their attachments? How many do we have?

Answer 148

**Origin:** Palmar aspect of 2^nd, 4^th, and 5^th metacarpal bones **Insertion:** Bases of proximal phalanges and extensor expansions of 2^nd, 4^th, and 5^th digits **Total of 3 Palmar Interosseous Muscles** - One for each of the 2^nd, 4^th, and 5^th digits * The Thumb has its own Adductors Pollicis, and the Third Digit doesn't adduct, it can only abduct in either direction.*

Question 149

**Palmar Interosseous Muscles** What is their action?

Answer 149

Adduction of the 2^nd-4^th digits ## Footnote *PAD Palmar ADduct*

Question 150

**Palmar Interosseous Muscles** What is the innervation and blood supply?

Answer 150

**Innervation:** Deep Ulnar Nerve **Blood Supply:** Palmar Metacarpal aa.