Shoulder; Muscles of

Question 1

Deltoid M.

Answer 1

Function:
Anterior – flexion, abduction,horizontal adduction, internal rotation
Middle – abduction
Posterior – extension, abduction, horizontal abduction, external
Origin: Anterior – clavicle Middle – distal clavicle and acromion Posterior – scapular spine
Insertion: Deltoid tuberosity of humerus
Innervation: axillary nerve (C5,6) from the posterior cord of the brachial plexus

Question 2

Biceps Brachii M.

Answer 2

Function: 
Shoulder flexion
Elbow flexion
Forearm supination
Origin:
Corocoid process
Superior glenoid cavity
Insertion: Radius
Innervation: musculocutaneous nerve (C5,6)

Question 3

Tricep Brachii M.

Answer 3

Function: Extension of the glenohumeral joint
Extension of the elbow
Origin: Long Head – Inferior glenoid rim
Lateral Head – humeral shaft
Medial Head – humeral shaft
Insertion: Olecranon process
Innervation: radial nerve

Question 4

Latissimus Dorsi M.

Answer 4

Function: Extension, Adduction and Internal rotation of the shoulder
Origin: Lower thoracic and lumbar spinous processes
Insertion: Anterior humerus
Innervation: thoracodorsal nerve (C7,8) from the posterior cord of the brachial plexus

Question 5

Teres Major M.

Answer 5

Function: Extension, adduction,internal rotation of the shoulder
Origin: Inferior angle of scapula
Insertion: Anterior humeral shaft
Innervation: axillary nerve (C5,6) from the posterior cord of the brachial plexus

Question 6

Pectoralis Major M.

Answer 6

Function: Adduction, flexion, internal rotation, and horizontal adduction of the shoulder
Origin: Sternum, clavicle
Insertion: Lesser tubercle of humerus
Innervation: medial and lateral pectoral nerves (C5-T1)

Question 7

Pectoralis Minor M.

Answer 7

Function: Scapular depression and protraction
Origin: Ribs 3-5
Insertion: Corocoid process
Innervation: medial pectoral nerve (C8, T1)

Question 8

Supraspinatus M.

Answer 8

Function: Abduction, stabilizes humeral head in glenoid fossa
Origin: Suprascapular fossa
Insertion: Greater tubercle of humerus
Innervation: suprascapular nerve (C5,6) from the superior trunk of the brachial plexus

Question 9

Infraspinatus M.

Answer 9

Function: External rotation, stabilizes humeral head in glenoid cavity
Origin: Infraspinous fossa
Insertion: Greater tubercle of humerous
Innervation: suprascapular nerve

Question 10

Teres Minor M.

Answer 10

Function: External rotation, stabilizes humeral head in glenoid cavity
Origin: Lateral border of scapula
Insertion: Greater tubercle of humerous
Innervation: axillary nerve (C5,6) from the posterior cord of the brachial plexus

Question 11

Subscapularis M.

Answer 11

Function: Internal rotation, stabilizes humeral head in glenoid cavity
Origin: Subscapular fossa
Insertion: Lesser tubercle of humerus
Innervation: upper and lower subscapular nerves (C5,6)

Question 12

Coracobrachialis M.

Answer 12

Function: GH flexion
Origin: Coracoid process
Insertion: Humeral shaft
Innervation: musculocutaneous nerve (C5,6)

Question 13

Serratus Anterior M.

Answer 13

Function: Protraction of the scapula
Origin: Ribs 1-9
Insertion: Medial border of the scapula
Innervation: long thoracic nerve (from ventral rami C5-C7)

Question 14

Levator Scapulae M.

Answer 14

Function: Scapular elevation
Origin: C3-C4 Transverse processes
Insertion: Superior angle of the scapula
Innervation: dorsal scapular nerve (C5); the upper part of the muscle receives branches of C3 & C4

Question 15

Rhomboids M.

Answer 15

Function: Retraction of scapula
Origin: Spinous processes of C7-T4
Insertion: Medial border of the scapula
Innervation: dorsal scapular nerve (C5)