Unit 2 - Upper Limb: Pectoralis Major and Coracobrachialis (Ex. II)

Question 1

sternocostal pectoralis major

Answer 1

O: sternum and costal cartilages 1-6
I: crest of greater tubercle of humerus
Inn: M and L pectoral N (C5-T1)
A: shoulder flexion; assists in respiration w/ shoulder fixed

Question 2

abdominal pectoralis major

Answer 2

O: A layer of rectus sheath
I: crest of greater tubercle of humerus
Inn: M and L pectoral N (C5-T1)
A: adduction; internal (M) rotation

Question 3

action of pectoralis major as a whole

Answer 3

adduction; internal (M) rotation

Question 4

coracobrachialis

Answer 4

O: coracoid process of scapula
I: on humerus in line w/ crest of lesser tubercle
Inn: musculocutaneous N (C5-C7)
A: flexion; adduction; internal (M) rotation

Question 5

clavicular pectoralis major

Answer 5

O: M 1/2 of clavicle
I: crest of greater tubercle of humerus
Inn: M and L pectoral N (C5-T1)
A: shoulder flexion; assists in respiration w/ shoulder fixed