muscles of the anterior axio appendicular shoulder

Question 1

Introduce Pectoralis major

Origin/insertion/action/nerve supply

Answer 1

Pec major is one of the anterior axioappendicular muscles
Origin 2 heads
-Clavicular head: medial 1/2 of clavicle
-Sternocostal head: anterior sternum and the first 6 costal cartilages
-Aponeurosis of the external oblique
Insertion
-Lateral lip of the bicipital groove
Action
-adduction and internal rotation of GH joint
-clavicular head: induces humeral flexion
-sternocostal head: induces humeral extension
Nerve supply
-Lateral pectoral and medial pectoral nerve

Question 2

Introduce the pectoralis minor

Origin/insertion/action/nerve supply

Answer 2

Pec minor is one of the anterior axioappendicular muscles. It lies deep to pec major 
Origin
-superior borders of ribs 3-5
Insertion
-medial border of the coracoid process 
Action 
- draws the scapula inferiorly
-stabilises scapula
-protracts scapula
Nerve supply
-Medial pectoral nerve

Question 3

Introduce the subclavius

Origin/insertion/action/nerve supply

Answer 3

Subclavius is one of the anterior axioappendicular muscles
Origin
-in between the 1st rib and 1st costal cartilage
Insertion
-inferior surface of the clavicle where the groove for subclavius lies
Action
-depression of the clavicle
-stabilises clavicle
-stabilises sternoclavicular joint during movement by pulling the clavicle medially
Nerve supply
-nerve to subclavius

Question 4

Introduce the serratus anterior

Origin/insertion/action/nerve supply

Answer 4

Serratus anterior is one of the anterior axioappendicular msucles
Origin
-lateral surfaces of ribs 1-8
-superficial and deep fascia covering the intercostal spaces
Insertion
-anterior aspect of the medial border of the scapula
Action
-stabilises scapula against the thoracic wall
-protracts scapula
-laterally rotates scapula
Nerve supply
-Long thoracic