Shoulder/ arm muscles

Question 0

Give origin, insertion, Innervation, and action of the rhomboids.

Answer 0

Minor: C7-T1 spinous processes and nuchal ligament to the vertebral border at the root of the scapula.
Major: T2-T5 spinous processes to the vertebral border of the scap inferior to the spine of the scap to the inferior angle.
Innervation: dorsal scapular nerve C4-C5
Action: retraction, depresses glenoid cavity, and fixes scap to thoracic wall.

Question 1

Give origin, insertion, Innervation, and action of the trapezius.

Answer 1

EOP, medial third of the superior nuchal line, nuchal ligament, C7-T12 spinous processes to the spine of the scapula, acromion, and lateral third of the clavicle.
Innervated by the spinal accessory nerve(CNXI), and C3-C4 for pain and proprioception.
Superior fibers elevate, inferior fibers depress, middle fibers retract the scap, and inf and sup fibers contracting together superiorly rotate the glenoid cavity.

Question 2

Give origin, insertion, Innervation, and action of the levator scapulae.

Answer 2

Posterior tubercles of the transverse processes C1-C4 to the vertebral border superior to the spine of the scap. But inferior to the superior angle.
Innervation: dorsal scapular nerve C5 and cervical spinal nerves C3-C4
Actions: elevates the scap and inferiorly rotates glenoid cavity.

Question 3

Give origin, insertion, Innervation, and action of the supraspinatus.

Answer 3

Supraspinous fossa of the scapula to the superior facet of the greater tubercle.
Innervation: suprascapular nerve C5-C6 (C4)
Action: first 15 degrees of abduction and stabilizes the humeral head in the glenoid cavity.

Question 4

Give origin, insertion, Innervation, and action of the infraspinous.

Answer 4

Infraspinous fossa of the scap to the middle facet of the greater tubercle.
Innervation: suprascapular nerve C5-C6
Action: external rotation and stabilizes the humeral head in the glenoid cavity.

Question 5

Give origin, insertion, Innervation, and action of the subscapularis.

Answer 5

The subscapular fossa of the scapula to the lesser tubercle of the humerus.
Innervation: upper and lower subscapular nerve C5-C7
Action: internal rotation, adducts, and stabilizes the humeral head.

Question 6

Give origin, insertion, Innervation, and action of the teres minor.

Answer 6

The middle part of the axillary border of the scapula to the inferior facet of the greater tubercle.
Innervation: is the axillary nerve C5-C6
Action: external rotation and stabilizes the head of the humerus in the glenoid cavity.

Question 7

Give origin, insertion, Innervation, and action of the teres major.

Answer 7

The inferior part of the axillary border and posterior surface of the inferior angle to the medial lip of the intertubercular sulcus on the humerus.
Innervation: lower subscapular nerve C5-C6
Action: adducts and medially rotates the the humerus.

Question 8

Give origin, insertion, Innervation, and action of the deltoid.

Answer 8

The lateral third of the clavicle, acromion, and spine of the scapula to the deltoid tuberosity on the humerus.
Innervation: Axillary nerve C5-C6
Action: anterior fibers medially rotate and flex the humerus. The middle fibers abduct the humerus. The posterior fibers extend and laterally rotate the humerus.

Question 9

Give origin, insertion, Innervation, and action of the latissimus dorsi?

Answer 9

The thoraco lumbar fascia, iliac crest, inferior 3-4 ribs, and T7-T12 spinous processes to the floor of the intertubercular sulcus.
Innervation is the thoracdorsal nerve C5-C7
Action: extension, medial rotation, and adduction.

Question 10

Give origin, insertion, Innervation, and action of the pectorialis major.

Answer 10

Anterior surface of the medial half of the clavicle, the anterior surface of the sternum, superior six costal cartilages, aponeurosis of the external oblique to the lateral lip of the intertubercular sulcus.
Innervation: lateral pectorial nerve C5-C6 and the medial pectorial nerve (sternocostal head) C7-T1
Actions: medial rotation. Acting alone the clavicular head flexes the humerus, and when the humerus is flexed the sternocostal head extends the humerus

Question 11

Give origin, insertion, Innervation, and action of the pectorialis minor.

Answer 11

Medial border and superior surface of the coracoid process to the 3-5th ribs near the costal cartilages.
Innervation: medial pectorial nerve C8-T1.
Action: stabilizes the scap by drawing it inferiorly and anteriorly against the thoracic wall.

Question 12

Give origin, insertion, Innervation, and action of the serratus anterior.

Answer 12

External surfaces of the lateral parts of the 1st to 8th rib to anterior and medial surface of the scapula.
Innervation: the long thoracic nerve C5-C7
Action: protracts the scap and holds it the the thoracic wall, rotates the scap.

Question 13

Give origin, insertion, Innervation, and action of the subclavius.

Answer 13

The junction of its first rib and costal cartilage to the inferior surface of the middle third of the clavicle.
Innervation: subclavian nerve C5-C6
Action: anchors and depresses the clavicle

Question 14

Give origin, insertion, Innervation, and action of the sternocleidomastoid.

Answer 14

Lateral surface of the mastoid process of the temporal bone and the lateral half of the superior nuchal line to the anterior surface of the manubrium and the medial third of the clavicle.
Innervation: spinal accessory CN XI and cervical spinal nerves C2-C3 for proprioception and pain.
Actions: bilaterally extension at the atlantooccipital joint and superior cervical vertebrae and flexion at the inferior vertebrae. Unilaterally causes contralateral rotation and and ipsilateral flexion.

Question 15

Give origin, insertion, Innervation, and action of the Anterior scalene.

Answer 15

Anterior tubercles of the transverse processes of C3-C6 to the 1st rib.
Innervation: cervical spinal nerves C4-C6
Action: flexes the head laterally and elevates 1st rib.

Question 16

Give origin, insertion, Innervation, and action of the middle scalene.

Answer 16

Posterior tubercles of the transverse processes of C4-C7 to the superior surface of the 1st rib posterior to the groove of the subclavian artery.
Innervation: anterior rami of cervical spinal nerves.
Actions: elevates the first rib and laterally flexes the neck

Question 17

Give origin, insertion, Innervation, and action of the posterior scalene.

Answer 17

The posterior tubercles of the transverse processes of C4-C6 to the external border of the 2nd rib
Innervation: anterior rami of the cervical spinal nerves of C7-C8
Action: lateral flexion and elevates the second rib.

Question 18

Give origin, insertion, Innervation, and action of the biceps brachii.

Answer 18

Short head: tip of the coracoid processor the scapula. Long head: the supra glenoid tubercle of the scapula to the radial tuberosity and bicital aponeurosis.
Innervation: musculocutaneous nerve C5-CC6
Actions: supinate and flex the forearm, flexes the humerus, and short head resists dislocation, and

Question 19

Give origin, insertion, Innervation, and action of the coracobrachialis.

Answer 19

Tip of the coracoid process of the scapula to the middle third of the medial surface of the humerus.
Innervation: musculocutaneous nerveC5-C7
Action: helps adduct and flex the shoulder as well as resist dislocation.

Question 20

Give origin, insertion, Innervation, and action of the brachialis.

Answer 20

Distal half of the anterior surface of the humerus to the corona is process and ulnar tuberosity.
Innervation: Musculocutaneous C5-C6
Action: chief flexor of the forearm

Question 21

Give origin, insertion, Innervation, and action of the triceps brachii.

Answer 21

Long head: infraglenoid tubercle of the scap.
Lateral head: posterior surface of the humerus superior to the radial groove.
Medial head: posterior surface of the humerus inferior to the radial groove
Inserts on the proximal end of the olecranon and fascia of the forearm.
Innervation: radial nerve C6-C8
Actions: chief extensors of the forearm and long head resists dislocation during abduction.