Muscles of the posterior shoulder and arm

Question 1

What is the origin/insertion of levator scapulae?

Answer 1

Origin: transverse processes of C1-C2 vertebrae, posterior tubercles of transverse processes of C3-4 vertebrae

Insertion: Superior angle of scapula, medial border of capula superior to spine of scapula

Question 2

What is the function of levator scapulae?

Answer 2

Elevates and downardly rotates pectoral (Shoulder) girdle at acromioclavicular joint and sternoclavicular joint

Extends and laterally flexes neck at cervical vertebral joints

Question 3

What innervates the levator scapulae?

Answer 3

Anterior rami of 3rd and 4th cervical nerves, sorsal scapular nerve (C5)

Question 4

What supplies blood to levator scapulae

Answer 4

Transverse cervical artery, ascending cervical artery, vertebral atrery

Question 5

What is the origin/insertion of latissimus dorsi?

Answer 5

Origin: Spinous processes of T7-12, same for L1-5, via thoracolumbar fascia 9th to 12th ribs, iliac crest

Insertion: Floor of intertubercular sulcus of humerus

Question 6

What is the action of latissimus dorsi?

Answer 6

Adducts, medially rotates, extends arm at genohumeral joint

Question 7

What innervates latissimus dorsi?

Answer 7

Thoracodorsal nerve (C6-8) (the only muscle in the region not innervated by the brachial plexus)

Question 8

What supplies the latissimus dorsi with blood?

Answer 8

Thoracodorsal artery,

Question 9

What are the origins/insertions to rhomboid major?

Answer 9

Origin: Spinous processes of T2-5

Insertion: Medial border of scapula inferior to spine of scapula

Question 10

What are the functions of rhomboid major?

Answer 10

Retracts and downwardly rotates pectoral (shoulder) girdle at acromioclavicular and sternoclavicular joints

Question 11

What innervates rhomboid major

Answer 11

Dorsal scapular nerve (C4-5)

Question 12

What supplies blood to rhomboid major?

Answer 12

Dorsal scapular artery, dorsal branches of 1st-6th posterior intercostal arteries

Question 13

What are the insertions of rhomboid minor?

Answer 13

Origins: Nuchal ligament, spinous processes of C7-T1

Insertion: Medial border of scapula adjacent to spine of scapula

Question 14

What are the functons of the rhomboid minor

Answer 14

Retracts and downwardly rotates pectoral girdle at acromioclavicualr and sternoclavicualr joints

Question 15

What innervates the rhomboid minor

Answer 15

Dorsal scapular nerve (C4-5)

Question 16

What supplies blood to the rhomboid minor?

Answer 16

Dorsal scapular artery, dorsal branches of 1st to sixth posterior intercostal arches

Question 17

What are the origins/insertions of triceps brachii?

Answer 17

Origin? Posterior humerus, infraglenoid tubercle of scapula

Insertion: Olecranon process, adjancent antebrachial fascia

Question 18

What is the action of the triceps brachii?

Answer 18

Extends forearm at elbow joint

Question 19

What innervates triceps brachii?

Answer 19

Radial nerve (C6-8)

Question 20

What supplies the triceps with blood

Answer 20

Deep brachial artery, superior ulnar collateral artery, posterior circumflex humeral artery