Intrinsic Muscles of the Glenohumeral Joint

Question 1

What are the origins of Deltoid?

Answer 1

• crest of SPINE of SCAPULA
• lateral margin of ACROMION
• lateral 1/3 of CLAVICLE

Question 2

What are the insertions of Deltoid?

Answer 2

Deltoid tuberosity of HUMERUS?

Question 3

What are the movements Deltoid participates in?

Answer 3

• abducts arm
• flex arm
• extend arm

Question 4

What is the innervation of Deltoid?

Answer 4

Axillary nerve (C5, C6)

Question 5

What are the muscles of the Rotator Cuff?

Answer 5

• Supraspinatus
• Infraspiantus
• Teres Minor
• Subscapularis

Question 6

What are the origins of SupraSpinatus?

Answer 6

Supraspinous fossa of the scapula

Question 7

What are the insertions of Supraspinatus?

Answer 7

-most superior facet on the greater tubercle of the humerus

Question 8

What does the supraspinatus muscle do?

Answer 8

• Initiates the abbduction of the arm to 15 degrees

- Stabilizes the glenohumeral joint

Question 9

What is the nerve supply of supraspinatus?

Answer 9

Suprascapular Nerve (C5, C6)

Question 10

What is the origin of Infraspinatus?

Answer 10

Infra spinatous fossa of the scapula

Question 11

What is the insertion of Infraspinatus?

Answer 11

MIDDLE facet on the posterior surface of the greater tubercle of the humerus.

Question 12

What is the nerve supply of infraspinatus?

Answer 12

Suprascapular nerve [C5, C6]

Question 13

What are the main actions of the Infraspinatus Muscle?

Answer 13

Lateral Rotation of the arm

Question 14

What are the origins of Teres MINOR?

Answer 14

Middle part of lateral border of scapula

Question 15

What are the insertions of Teres MINOR?

Answer 15

Inferior facet on greater tubercle of the humerus

Question 16

What is the nerve supply of Teres MINOR?

Answer 16

Axillary Nerve (C5, C6)

Question 17

What is the main action of teres minor?

Answer 17

Lateral rotation of the arm

Question 18

What is the origin of Teres MAJOR?

Answer 18

Inferior angle of Scapula

Question 19

What is the insertion of Teres Major?

Answer 19

Medial Lip of intertubercular groove (bicipital groove) of humerus

Question 20

What is the nerve supply of Teres Major?

Answer 20

Lower subscapular nerve (C6)

Question 21

What is the action of Teres MAJOR?

Answer 21

Adducts medially

rotates humerus

Question 22

What are the origins of subscapularis?

Answer 22

Subscapular fossa of scapula

Question 23

What are the insertions of subscapularis?

Answer 23

Lesser tubercle of humerus

Question 24

What is the nerve supply of subscapularis?

Answer 24

Upper (C5) and lower (C6) subscapular nerves

Question 25

What is the action of subscapularis?

Answer 25

Medial rotator and adductor of humerus | stabilize gleno-humeral joint

Question 26

What are the boundaries of the quadrangular space?

Answer 26

``` Superiorly = Teres Minor Inferiorly = Teres Major Medially = Long head of Triceps Brachii Laterally = Humerus ```

Question 27

Which artery and nerve are located within the quadrangular space?

Answer 27

- Axillary Nerve (C5, C6) | - Posterior circumflex artery + vein

Question 28

Which muscles is responsible for the initiation of abduction?

Answer 28

Supraspinatous

Question 29

What is the origin of the long head of Biceps Brachii?

Answer 29

supraglenoid tubercle of scapula

Question 30

What is the origin of the short head of Biceps Brachii?

Answer 30

coracoid process of scapula

Question 31

What is the insertion of biceps brachii?

Answer 31

Radial tuberosity

Question 32

What is the origin of the long head of triceps brachii?

Answer 32

infraglenoid tubercle of scapula

Question 33

What is the insertion of Triceps Brachii?

Answer 33

Olecranon Process of Ulna

Question 34

Contraction of which muscles produce protraction of the scapula?

Answer 34

- pectoralis Major - Pectoralis Minor - Serratus Anterior

Question 35

Contraction of which muscles produce retraction of the scapula?

Answer 35

Rhomboid Major Rhomboid minor Latissimus dorsi Trapezius

Question 36

Contraction of which muscles cause elevation of the scapula?

Answer 36

Trapzius Levator Scapulae Rhomboid Major / minor

Question 37

Contraction of which muscles cause depression of the scapula?

Answer 37

``` Pectoralis Major Pectoralis Minor Latissimus dorsi Trapezius Serratus Anterior ```

Question 38

Lateral Rotation is caused by the contraction of which muscles?

Answer 38

Infraspinatus | Teres Minor