Upper limb - Anterior and posterior axioappendicular (MSK)

Question 1

Trapezius

Origin, insertion, innervation, action

Answer 1

• Spinous process of C1-T12, occipital bone of the skull and nuchal ligament
• Clavicle, acromion process and spine of scapula
• CN XI,
• Elevates (superior fibres), retracts (Middle fibres) and rotates during abduction of the scapula

Question 2

Latissimus dorsi

Origin, insertion, innervation, action

Answer 2

• Spinous process of T7-T12, iliac crest, thoracolumbar fascia and ribs 10, 11, 12
• Inter tubercular groove of the humerus
• Thoracodorsal nerve (C6-C8) posterior cord
• Extend, adduct and medially rotate upper limb

Question 3

Levator scapulae

origin, insertion, innervation, action

Answer 3

• Transverse process of (C1-C4)
• Medial border off the scapula
• Dorsal scapular nerve
• Elevates the scapula

Question 4

Rhomboid minor

origin, insertion, innervation, attachment

Answer 4

• Spinous process of C7-T1
• Medial border of the scapula
• Dorsal scapular nerve
• Retracts and downward rotates the scapula

Question 5

Rhomboid major

origin, insertion, innervation, action

Answer 5

• Spinous process of T2-T5
• Medial border of the scapula
• Dorsal scapular nerve
• Retracts and downwardly rotates

Question 6

Supraspinatus (rotator cuff muscle)

origin, insertion, innervation, action

Answer 6

• Supraspinous fossa of scapula and deep fascia (superior trunk of brachial plexus)
• superior facet of greater tubercle of humerus
• supra scapular nerve (C5-C6)
• Initiates arm abduction (first 15 degrees)

Question 7

Infraspinatus (rotator cuff muscle)

origin, insertion, innervation, action

Answer 7

• Infraspinous fossa of scapula and deep fascia
• middle facet of greater tubercle of humerus
• supra scapular nerve (C5-C6)
• Laterally rotates arm at shoulder

Question 8

Teres minor (rotator cuff muscle)
origin, insertion, innervation, action

Answer 8

• Lateral border of the scapula
• Inferior facet of greater tubercle of humerus
• Axillary nerve (C5-C6)
• Laterally rotates arm at shoulder

Question 9

Teres major (rotator cuff muscle)
origin, insertion, innervation, action

Answer 9

• Posterior surface of inferior angle of the scapula
• medial lip of intertubercular groove of humerus
• Lower sub scapular nerve (C5-C6)
• Extends arm and medially rotates

Question 10

Subscapularis (rotator cuff muscle)

origin, insertion, innervation, action

Answer 10

• Subscapular fossa of scapula
• Lesser tubercle of humerus
• Upper and lower sub scapular nerves (C5-C6)
• Medially rotates arm at shoulder and adducts it

Question 11

Pectoralis major

Origin, insertion, innervation, action

Answer 11

• Medial clavicle (clavicular head) sternum and ribs 1 - 6 (sternocostal head)
• Intertuberculer groove of the humerus
• Adducts and medially rotates the humerus
• Medial and lateral pectoral nerves

*Accessory muscle of inspiration

Question 12

Pectoralis minor

Origin, insertion, innervation, action

Answer 12

• Coracoid process of scapula
• Ribs 3-5 (number of letters in pec minor)
• Medial pectoral nerve
• Protracts scapula and stabilises it

Question 13

Serratus anterior

Origin, insertion, innervation, action

Answer 13

• Upper 8 ribs
• Medial border and inferior angle of the scapula
• Long thoracic nerve
• Rotates and protracts scapula

Question 14

Deltoid muscle

Origin, insertion, innervation, action

Answer 14

• Lateral 3rd of clavicle, acromion process and spine of scapula
• Deltoid tuberosity
• Axillary nerve
• Anterior fibres flex the arm, middle fibres abduct past 15 degrees, posterior fibres extend the arm
• Abducts past 15 degrees (15-90)

Question 15

Median nerve

Answer 15

• Runs medially into the midline at the forearm and into the carpal tunnel of the hand
• Innervates thenar muscles (thumb) and two lateral lumbricals, flexor muscles of the anterior forearm except flexor carpi ulnas and lateral half of flexor digitorum profundus
• Cutaneous innervation to 3.5 digits on palmar aspect and tips of same digits on dorsal aspect

Question 16

Ulnar nerve

Answer 16

• Runs medially down the arm passing posterior to the medial epicondyle
• Innervates flexor carpi ulnaris and median half of flexor digitorum profundus, muscles of the hand apart from the ones the median nerve does (thenar and lateral 2 digits)
• Cutaneous innervation to medial 1.5 digits on palmar aspect and the same digits on dorsal aspect

Question 17

Radial nerve

Answer 17

• Moves out of triangular interval and moves down groove of the humerus with profound brachii artery
• Innervates all muscles in the posterior compartment of the arm
• Cutaneous innervation to the 3.5 digits on dorsal aspect
• Wraps medial shaft of the humerus

Question 18

Musculocutaneous nerve

Answer 18

• Runs most laterally in the arm and pierces coracobarchialis
• Supplies biceps brachii, brachialis, coracobrachialis
• Cutaneous innervation to the skin of the forearm

Question 19

Axillary nerve

Answer 19

• Passes out through the quadrangular space
• Innervates deltoid and teres minor
• Cutaneous innervation to the regimental patch of the arm
• Wraps around the surgical neck of the humerus