Muscles of the lateral and posterior wall of the axilla

Question 1

Subscapularis

Answer 1

Origin:

• Medial two thirds of sub scapula fossa

Insertion:

• Lesser tubercle of humorous

Innervation:

• Upper and lower sub scapular nerves (C5, C6, (C7))

Function:

• Rotator cuff muscles
• Medial rotation of the arm at the glenohumeral joint

Question 2

Teres major

Answer 2

Origin:

• Elongate oval area on the posterior surface of the inferior angle of the scapula

Insertion:

• Medial lip of the inter tubercular sulcus on the anterior surface of the humerus

Innervation:

• Lower scapular nerve (C5, C6, C7)

Function:

• Medial rotation and extension of the arm at the glenohumeral joint

Question 3

Latissimus dorsi

Answer 3

Origin:

• Spinous processes of lower six thoracic vertebrae and related interspinous ligaments;
• Via the thoracolumbar fascia to the spinous processes of the lumbar vertebrae,
• Related interspinous ligaments
• Iliac crest; l
• Lower 3-4 ribs

Insertion:

• Floor of inter tubercular sulcus

Innervation:

• Thoracodorsal nerve (C6, C7, C8)

Function:

• Adduction,
• Medial rotation, and
• Extension of the arm at the glenohumeral joint

Question 4

Long head of triceps brachii

Answer 4

Origin:

• Infraglenoid tubercle on scapula

Insertion:

• Common tendon of insertion with medial
• Lateral heads on the olecranon process of ulna

Innervation:

• Radial nerve (C6, C7, C8)

Function:

• Extension of the forearm at the elbow joint;
• Accessory adductor and extensor of the arm at the glenohumeral joint