Upper Limb Muscles

Question 1

Lat dorsi

• Origin
• Insertion
• Innervation
• Action

Answer 1

• Origin: thoracolumbar fascia
• Insertion: intertubucular groove of humerus
• Innervation: thoracodorsal
• Action: Adducts/extends/medially rotates arm

Question 2

Teres major

• Origin
• Insertion
• Innervation
• Action

Answer 2

• Origin: inferior angle of scapula
• Insertion: medial lip of the bicipital groove
• Innervation: Lower subscapular nerve
• Action: extends arm at shoulder joint

Question 3

Teres minor

• Origin
• Insertion
• Innervation
• Action

Answer 3

• Origin: inferior lateral border of scapula
• Insertion: greater tubercle of humerus
• Innervation; axillary
• Action: lateral rotation, adducts and medially rotates arm

Question 4

Levator scapulae

• Origin
• Insertion
• Innervation
• Action

Answer 4

• Origin: Transverse process C1-C4
• Insertion: Medial border of scapula
• Innervation: C3-C4, Dorsal scapula nerve/ superior trunk of brachial plexus
• Action: elevates scapula

Question 5

Pectoralis major

• Origin
• Insertion
• Innervation
• Action

Answer 5

• Origin: medial half of clavicle, sternum, upper 6 costal cartiliage
• Insertion: Lateral lip of the bicipital groove
• Innervation: medial and lateral pectoral
• Action: Adduction, flexion and medial rotation of the arm

Question 6

Pectoralis minor

• Origin
• Insertion
• Innervation
• Action

Answer 6

• Origin: 3, 4, 5th rib
• Insertion: coracoid process of scapula
• Innervation: medial pectoral nerves
• Action: stabilizes scapula, depresses and protracts scapula