Muscular System Pt. 4

Question 1

Where do all the muscles of the shoulder originate?

Answer 1

At the scapula

Question 2

Origin of Deltoid

Insertion of Trapezius is the exact same

Answer 2

1. Acromion Process
2. Clavicle
3. Spine of scapula

Question 3

Insertion of Deltoid

Answer 3

Deltoid tuberosity on humerus

Along the shaft of the long bone

Question 4

Actions of Deltoid

Answer 4

• Flexion of humerus
• Extension of humerus
• Lateral rotation of humerus
• Medial rotation of humerus
• Abduction of humerus

Question 5

Which muscles make up the rotator cuff?

Answer 5

Supraspinatus, Infraspinatus, Teres Minor and Subscapularis

Teres Major is not a Rotator Cuff Muscle

Question 6

Purpose of rotator cuff muscles?

Answer 6

Stabilize the shoulder joint between the humerus and glenoid fossa

Question 7

Origin of Supraspinatus

Answer 7

Supraspinous fossa of scapula

Posterior superior

Question 8

Insertion of Supraspinatus

Same as Infra. and Teres

Answer 8

Greater Tubercle of Humerus

Question 9

Actions of Supraspinatus

Answer 9

Abduction of humerus

Question 10

Origin of Infraspinatus

Answer 10

Infraspinous fossa of scapula

Question 11

Insertion of Infraspinatus

Answer 11

Greater tubercle of humerus

Also the same as supra and teres minor because all posterior and above or under one another

Question 12

Actions of Infraspinatus

Answer 12

Lateral rotation of humerus

Question 13

Lateral Border of Scapula

Answer 13

Origin of Teres Minor

Question 14

Greater Tubercle of humerus, below infraspinatus

Similar to Supraspinatus & Infraspinatus

Answer 14

Insertion of Teres Minor

Question 15

Actions of Teres Minor

Answer 15

• Lateral rotation of humerus
• Extension of humerus

Question 16

Origin of Subscapularis

Answer 16

Subscapular fossa of scapula

Question 17

Insertion of subscapularis

Answer 17

Lesser tubercle of humerus

Question 18

Actions of subscapularis

Answer 18

Medial rotation of humerus

Question 19

Inferior angle of scapula

Answer 19

Origin of Teres Major

Question 20

Distal attachment/insertion of Teres Major

Answer 20

Bicipital groove of humerus (anterior side)

Question 21

Actions of Teres Major

Answer 21

• Medial rotation of arm
• Extension of arm
• Adduction of humerus