Scapulohumeral Muscles

Question 0

Where does the deltoid insert?

Answer 0

Deltoid tuberosity of the humerus

Question 1

What is the origin of the deltoid?

Answer 1

Lateral third of the clavicle; acromion and spine of the scapula

Question 2

What is the innervation of the deltoid?

Answer 2

Axillary nerve (C5, C6); main segmental innervation from C5

Question 3

What actions does the deltoid perform?

Answer 3

Clavicular (anterior): flexes and medially rotates shoulder joint
Acromial (middle): abducts shoulder joint
Spinal (posterior): extends and laterally rotates shoulder joint

Question 4

What is the origin of the supraspinatus?

Answer 4

The supraspinous fossa of scapula

Question 5

Where does the supraspinatus insert?

Answer 5

Superior facet of greater tubercle of humerus

Question 6

What is the innervation of the supraspinatus?

Answer 6

Suprascapular nerve (C4, C5, C6); main segmental innervation from C5

Question 7

What action does the supraspinatus perform?

Answer 7

Initiates and assists deltoid in abduction of shoulder joint and acts with other rotator cuff muscles

Question 8

What is the origin of the infrapsinatus?

Answer 8

The infraspinous fossa of the scapula

Question 9

Where does the infraspinatus insert?

Answer 9

Middle facet of greater tubercle of humerus

Question 10

What is the innervation of the infraspinatus?

Answer 10

Suprascapular nerve (C5, C6); main segmental innervation from C5

Question 11

What action does the infraspinatus perform?

Answer 11

Laterally rotates shoulder joint; helps hold humeral head in glenoid cavity of scapula

Question 12

What is the origin of the teres minor?

Answer 12

The middle part of the lateral border of the scapula

Question 13

Where does the teres minor insert?

Answer 13

Inferior facet of greater tubercle of humerus

Question 14

What is the innervation of the teres minor?

Answer 14

Axillary nerve (C5, C6); main segmental innervation from C5

Question 15

What action does the teres minor perform?

Answer 15

Laterally rotates shoulder joint; helps hold humeral head in glenoid cavity of scapula

Question 16

Where does the teres major originate?

Answer 16

The inferior part of the lateral border of scapula and posterior surface of inferior angle of scapula

Question 17

Where does the teres major insert?

Answer 17

The medial lip of the intertubercular sulcus of the humerus

Question 18

What is the innervation of the teres major?

Answer 18

Lower subscapular nerve (C5, C6); main segmental innervation from C6

Question 19

What action does the teres major perform?

Answer 19

Adducts and medially rotates the shoulder joint

Question 20

What is the origin of the subscapularis?

Answer 20

The subscapular fossa

Question 21

Where does the subscapularis insert?

Answer 21

Lesser tubercle of humerus

Question 22

What is the innervation of the subscapularis?

Answer 22

Upper and lower subscapular nerves (C5, C6, C7); main segmental innervation from C6

Question 23

What action does the subscapularis perform?

Answer 23

Medially rotates and adducts shoulder joint; helps hold humeral head in the glenoid cavity