Anterior axio-appendicular skeleton muscles (JO)

Question 1

Name this muscle:
State its Origin(s), Insertion(s), Innervation(s), and Action(s)

Answer 1

Subclavius

Origin: Rib 1 & sternum junction

Insertion: Middle 3rd of clavicle

Innervation: Subclavian nerve (C5)

Main Action: Stabilizes and depresses clavicle

Question 2

Name this muscle:
State its Origin(s), Insertion(s), Innervation(s), and Action(s)

Answer 2

Serratus Anterior

Origin: External surface of ribs 1 - 8

Insertion: Medial border of scapula

Innervation: Long Thoracic Nerve (C6 - C7)

Action: Protracts scapula, holds scapula against thoracic wall; rotates scapula upwards (can cause “winging” of scapula)

Question 3

Name this muscle
State its Origin(s), Insertion(s), Innervation(s), and Action(s)

Answer 3

Pectoralis Major
Origin:
(Clavicular head): anterior surface of the clavicle
(Sternocostal head): anterior surface of the sternum and
superior six costal cartilages.
(Abdominal head): aponeurosis of external oblique

                         Insertion: Lateral lip of the intertubercular sulcus of 
            humerus

                       Innervation: Lateral and medial pectoral nerves.
               -C5, C6: clavicular head
               -C7, C8: sternocostal head

                              Action: Adducts and medially rotates the GH joint; (acting alone: clavicular head flexes the shoulder and sternocostal head extends the shoulder from a flexed position)

Question 4

Name this muscle
State its Origin(s), Insertion(s), Innervation(s), and Action(s)

Answer 4

Pectoralis Minor
Origin: ribs 3-5
Insertion: Coracoid process of scapula
Innervation: Medial pectoral nerve
Action: Stabilizes the scapula by drawing it inferiorly and anteriorly against thoracic wall (protracts scapula)