Upper Limb muscles 1.2

Question 1

What is the origin of the biceps brachii?

Answer 1

1. Short head: from apex of coracoid process of scapula

2. Long head: supraglenoid tubercle of the scapula

Question 2

What is the insertion of biceps brachii?

Answer 2

1. Both muscle bellies joint to form flattened tendon that is inserted into radial tubersority
2. Opposite elbow tendon gives off a broad aponeurosis from its medial side
3. This bicipital aponeurosis descends medially to fuse with the deep fascia of the forearm

Question 3

What is the action of the biceps brachii?

Answer 3

• With the forearm partially flexed, the biceps brachii is a powerful supinator of the forearm
• Also important flexor of the supinated forearm
• Asssits other muscles weakly as flexor of arm at shoulder

Question 4

What is the innervation of the biceps brachii?

Answer 4

Musculocutaenous nerve (C5 and C6)

Question 5

What is arterial supply for biceps brachii?

Answer 5

• The biceps is a fusiform muscle with 2 heads

- Brachial artery

Question 6

What is the test for C5 and C6?

Answer 6

1. Tapping the biceps tendon elicits the biceps tendon reflex, testing spinal cord segments C5 and C6
2. The biceps is tested clinically by having a patient flex the supinated forearm against resistance and watching for the distinct contraction of the biceps in the anterior arm
3. This action also tests the integrity of the musculocutaneous nerve.

Question 7

What is the origin of the coracobrachialis muscle?

Answer 7

arises fro apex of coracoid process of scapula along with the short head of the biceps brachii

Question 8

What is the insertion of the coracobrachialis muscle?

Answer 8

Inserts into the middle of the medial surface and border of the humerus

Question 9

What is the action of the coracobrachialias muscle?

Answer 9

Flexes and adducts the arm at the shoulder

Question 10

What is the innervation of the coracobrachialis muscle?

Answer 10

Musculocutanous nerve (C6 and C7)

Question 11

What is the blood supply for the coracobrachialis muscle?

Answer 11

• Branchial artery
• As the musculocutaneous nerve leaves the brachial plexus, it usually dives into the proximal portion of the coracobrachialis muscle

Question 12

Why is the musculatenous nerve vulnerable?

Answer 12

Since the musculocutaneous nerve runs through the coracobrachialis muscle, it is vulnerable to nerve compression within the muscle, and this can lead to weakness of elbow flexion (loss of some brachialis and biceps function) and hypesthesia of the lateral forearm

Question 13

What is the origin of the brachialis muscle?

Answer 13

Arises from distal half of the anterior humerus

Question 14

What is the insertion of the brachialis muscle?

Answer 14

Inserts into the tuberosity and the anterior surface of the coronoid process of the ulna

Question 15

What is the action of the brachilias?

Answer 15

Flexor of forearm at the elbow

Question 16

What is the innervation of the brachilias?

Answer 16

musculatenous nerve (C5, C6) and radial nerve send minor branch to brachialis (C7)

Question 17

What is the blood supply for the brachialis?

Answer 17

• Brachial artery
• Although the muscle can participate in quick flexion, its isometric contraction maintains the flexed position, especially when a weight is applied to the forearm

Question 18

What is a compression injury?

Answer 18

Damage to the musculocutaneous nerve proximal to the brachialis (compression injury as it passes through the coracobrachialis muscle) can lead to weakness in the brachialis and biceps brachii muscles, thus affecting elbow flexion.

Question 19

What is the origin of the triceps?

Answer 19

1. Long head of triceps arises from infraglenoid tubercle of scapula
2. Lateral head arises from posterior surface of humerus
3. Medial head arises from posterior surface of humerus inferior to the radial groove
4. The anconeus arise from lateral epicondyle of the humerus

Question 20

What is the insertion of the triceps and anconeus?

Answer 20

1. All 3 heads insert by common tendon to posterior portion of proximal olecranon of the ulna
2. A band of fibres continues distally on the lateral side over the anconeus to blend with the Depp fasciae of the forearm
   - The anconeus inserts into the lateral aspect of the olecranon and into the upper dorsal surface of the body of the ulna

Question 21

What is the action of the triceps and anconeus?

Answer 21

• The aconenus muscle and all 3 heads of triceps extend the forearm at the elbow
• Anconeus also abducts the ulna during pronation
• The long head of the triceps arising from the scapula also can extend the humerus (arm) at the shoulder joint

Question 22

What is the innervation of the triceps and anconeus?

Answer 22

The triceps and anconeus supplied boy radial nerve (c7 and c8)

Question 23

Where does triceps receive blood?

Answer 23

Deep brachial artery

Question 24

What does the triceps reflex do?

Answer 24

• Tapping the triceps tendon elicits the triceps reflex

- Test C7 and C9

Question 25

What does msuculatenous nerve innervate?

Answer 25

- Muscles of anterior (flexors) compartment | - Supplied by brachial artery and branches

Question 26

What does radial nerve innervate?

Answer 26

- Muscles of posterior (extensor) compartment | - Supplied largely by deep brachial (profound brachii) artery and its branches

Question 27

Which nerves pass through the arm in a medial vascular bundles compartment?

Answer 27

- The median and ulnar nerves pass through the arm in a medial neurovascular bundle compartment as they course to the forearm. - These 2 nerves do not innervate muscles of the arm.

Question 28

When is the radial nerve in jeprody?

Answer 28

1. The radial nerve passes around the shaft of the humerus to gain access to the posterior compartment of the arm 2. Fractures of the shaft of the humerus can place the radial nerve in jeopardy of being stretched or torn as it wraps around the humerus, affecting wrist and finger extensors.

Question 29

What is the origin of the pronator teres?

Answer 29

1. Humeral head arises immediately above medial epicondyle from common flexor tendon, intermsucular septum and anterbrshcial fascia 2. Ulnar head arises from medial side of coronoid process of ulna

Question 30

Where does the pronator quadratus raise form?

Answer 30

-Medial aspect of the anterior surface of the distal one-fourth of the ulna

Question 31

What is the insertion of the pronator teres?

Answer 31

-Inserts about midway along the lateral surface of the radius

Question 32

What is the insertion of the pronator quadratus?

Answer 32

-inserts into distal fourth of the lateral border and anterior surface of the shaft of the radius

Question 33

What is the action of the pronator teres?

Answer 33

rotes the radius on the ulna (pronation) and helps flex the forearm at the elbow

Question 34

What is the action of the pronator quadratus?

Answer 34

pronates the hand and is assisted by the pronator teres when additionsl power is required

Question 35

What is the innervation of the pronator quadratus and pronator teres?

Answer 35

Innervated by median nerves pronator teres (C6 and C7), pronator quadrates (C8 and T1)

Question 36

What is a test for pronator teres?

Answer 36

- One clinically tests the pronator teres by grasping the patient’s hand with the forearm extended and asking the patient to pronate against resistance (turn the hand downward) while watching the medial epicondyle of the humerus to see if the muscle contracts. - The pronator teres is well suited for quick, powerful pronation. - The pronator quadratus is the deepest muscle in the forearm, and its contraction is difficult to show

Question 37

What is the origin of the flexor carpi radialis muscle?

Answer 37

-Arises from medial epicondyle of humerus and anterbrachial forearm) fasciae

Question 38

What is the insertion of the flexor carpi radialis muscle?

Answer 38

Inserts into base of 2nd metacarpal bone and sends a slip to the base of the 3rd metacarpal bone

Question 39

What is the action of the flexor carpi radialis?

Answer 39

flexes hand at the wrist join and Aids in first abduction

Question 40

What is the innervation of the fexor carpi radialis?

Answer 40

Median nerve C6 and C7

Question 41

What is a clinical test for the flexor carpi radialis?

Answer 41

- One can clinically test the flexor carpi radialis by grasping the patient’s hand and having the patient flex the wrist against resistance. - As the patient does this, look for the tendon of the muscle to tighten in the wrist.

Question 42

How can you see the radial artery pulse?

Answer 42

- The radial extensors help the flexor carpi radialis abduct the wrist. - Distally at the wrist, the radial artery pulse may be palpated just lateral to the tendon of this muscle. Simply rest your index and middle fingers on this tendon and press to feel the radial pulse.

Question 43

What is the origin of the paslmaris longus muscle?

Answer 43

From medial epicondyle of the humerus by the common flexor tendon and antebrachila (forearm fascia)

Question 44

What is the insertion of the palmaris longus muscle?

Answer 44

Inserts into anterior aspect of distal flexor retianculum and into the palmar aponeurosis

Question 45

What is the action of the palmaris longus muscle?

Answer 45

Flexes the hand at the wrist and tightens the palmar aponeurosis

Question 46

What is the innervation of the palmaris longus muscle?

Answer 46

median nerve (C6 and C7)

Question 47

How can you determine if patient has palmaris longus?

Answer 47

- The palmaris longus is vestigial in humans and is absent in 10% to 15% of the population. - In other species, this muscle retracts the claws. In humans, it acts primarily at the wrist. - By having the patient make a tight fist, one can determine if the patient possesses the palmaris longus muscle, as its tendon will appear in the midwrist - The median nerve lies just lateral to the tendon of this muscle before entering the carpal tunnel

Question 48

What is the origin of the flexor carpi ulnaris muscle?

Answer 48

1. Humeral head arises from medial epicondyle of humerus by the common flexor tendon 2. Ulnar head arises from medial margin pf the olecranon and posterior border of the ulna

Question 49

What is the insertion of the flexor carpi ulnaris muscle?

Answer 49

- Inserts into pisiform bone but an extension of its ligament attaches to the hook of hamate and base of the 5th metacarpal - Several of its fibres also attach to the flexor retinaculum

Question 50

What is the action of the flexor carpi ulnaris muscle?

Answer 50

Flexes and adducts the hand at the wrist

Question 51

What is the innervation of the carpi ulnaris muscle?

Answer 51

Ulnar nerve (C7 and C8)

Question 52

When do the two head of the flexor carpi ulanris muscle join?

Answer 52

- The 2 heads of this muscle join just below the medial epicondyle; the ulnar nerve runs between the heads as it courses toward the wrist. - The ulnar extensor helps the flexor carpi ulnaris adduct the hand at the wrist.

Question 53

What is cubital tunel syndrome?

Answer 53

- As the ulnar nerve passes between the 2 heads of the flexor carpi ulnaris, the nerve can become compressed, leading to a cubital tunnel syndrome. - This syndrome is 2nd only to carpal tunnel syndrome among compression neuropathies. - Compression may be especially acute as the elbow is flexed because this narrows the space between the 2 muscle heads.

Question 54

What is the innervation of the flexor digitorum superficialis muscle?

Answer 54

- Arises by 2 heads and inserts by 4 tendons 1. The humeroulnar head arises from the medial epicondyle of the humerus, the ulnar collateral ligament and the coronoid process of the ulna 2. The radial head arises from the superior half of the anterior aspect of the radius

Question 55

What is the insertion of the flexor digitorium superficialis muscle?

Answer 55

-Four tendons of insertion of the flexor digitorum superifcialis attach to the bodies of the middle phalanges of the medial 4 digits (index to little finger)

Question 56

What is the action of the flexor digitorium superficialis muscle?

Answer 56

- Acts primarily as a flexor of proximal interphalangeal joints - Also contributes to flexion pf all joints it crosses including elbow wrist and metcrpophalngeal joints

Question 57

What is the innervation of the flexor digitorium superficialis muscle?

Answer 57

median nerve (C7, C8 and T1)

Question 58

What is the common synovial tendon sheath?

Answer 58

- Opposite the bases of the 1st phalanges, each tendon divides to allow the corresponding tendon of the deep flexor (flexor digitorum profundus) to reach each finger. 1. A common synovial tendon sheath, or bursa, wraps around both sets of tendons, facilitating the sliding of the tendons over one another

Question 59

How do you test the flexor digitorium superficialis muscle?

Answer 59

- asking the patient to flex the index or middle finger while one holds it between the thumb and index finger in a flexed position at the proximal interphalangeal joint, thus providing resistance - As the patient tries to flex the joint and move the finger toward the palm, the muscle’s strength can be assessed.

Question 60

What is the origin of the flexor digitorum profundus muscle?

Answer 60

-Arises from proximal three fourths of medial and anterior aspects of the ulna and from the interosseous membrane

Question 61

What is the insertion of the flexor digitorum profundus muscle?

Answer 61

-Four tendons of the flexor digitorum produndus attach to the bases of the distal phalanges of the medial 4 digitised (index finger to little finger)

Question 62

What is the action of the flexor digitorum profundus muscle?

Answer 62

- Flexion of distal interphlangeal joints - Also produces some flexion at the proximal interphalangeal lints, metacarpophalangea; joints and wrist as tendons cross these joints

Question 63

What is the innervation of the flexor digitorum profundus muscle?

Answer 63

-Proximal to wrist flexor digitorium divides into 3, medial part innervated by ulnar (C8 and T1) and lateral by anterior interosseous brach of median nerve (C1 and T1)

Question 64

How are tendons different to those of superficialis?

Answer 64

The tendons of the flexor digitorum profundus, similar to those of the superficialis, cross the carpal canal and the palm of the hand. The 4 tendons pass through the slits of the superficialis tendons before attaching to the distal phalanges

Question 65

How do you test the flexor digitorum profundus muscle?

Answer 65

-The flexor digitorum profundus muscle is tested clinically by having the patient flex the distal interphalangeal joint against resistance as one places the thumb and index finger on the proximal interphalangeal joint of the tested finger to keep it in extension and then holds the tip of the finger to provide resistance to flexion of the distal interphalangeal joint.