Shoulder Muscles connecting shoulder girdle to thorax

Question 1

Serratus Anterior

Answer 1

PA: Upper 8 ribs along external surfaces and superior borders, and to fascia of adjoining intercostal mm.

DA: Scapula along medial border of anterior (velar) surface

Inn: Long Thoracic nerve (C5,6,7)

Actions: Scapular upward rotation, protraction, prevents scapular winging.

Question 2

Pectoralis Major

Answer 2

PA: Med 1/2 clavicle along anterior portion, sternal anterior 1/2 surface. Ribs 1-7 C.C, sternal end of rib 6, Aponeurosis of EAO.

DA: Lat lip if bicipital groove

Inn: Med and lat pect clavicular nerve: C5,6
Sternal nerve: C6-T1

Action: OC: Adduction and med rot of humerus
Clavicular: Flex and extended arm
Sternal: Extend a flexed arm
CC: Draws trunk upward and forward.

Question 3

Pectoralis Minor

Answer 3

PA: Ribs 3-5 along upper margin and outer surface near C.C; Fascia over adjoining external intercostal muscle.

DA: Corocoid process along medial border and upper surface

Inn: Med and lat pectoral: C5-T1

Action: Scapular depression assists with protraction

Question 4

Subclavius

Answer 4

PA: 1st rib at junction of rib and C.C

DA: Groove on med 1/3 inferior portion of clavicle

Inn: N to subclavius C5,6

ACT: Shunting the clavicle towards manubrium during violent extremity motions (hitting or throwing); Clavicular depression and protraction.

CC: Secondary muscle of respiration