Anterior axioappendicular/Pectoral Muscles Flashcards
What make up the 4 components of the Pectoral muscles
- Pectoralis Major
- Pectoralis Minor
- Subclavius
- Serratus anterior
Where is the proximal attachment of the Pectoralis Major?
It attaches to the Clavicular head, the medial half of the clavicle.
It also attaches at the Sternocostal head, at the anterior sternum and superior 6 costal cartilages.
Where is the distal attachment for the Pectoralis Major?
At the lateral lip of the intertubercular groove.
What is the nerve supply of the pec major? How can you remember this?
The lateral and medial pectoral nerves.
Because its such a large muscle, it needs two nerve supplies.
What is the action of the pec major?
To adduct and medially rotate the humerus. The clavicular head flexes the humerus.
Where does the Pectoralis Minor proximall attach?
At the 3rd and 5th ribs near their costal cartilages.
Where does the pec minor distally attach?
The pec minor distally attaches at the Coracoid process of the scapula.
What nerve supplies the pec minor?
The medial pectoral nerve.
What is the action of the pec minor?
The action is to stabilise the scapula by drawing it inferiorly and anteriorly on the thoracic cage.
Identify the muscle below and what it protects.
This muscle is the subclavius, it is below the clavicle.
It protects the underlying vessels and nerves during clavicle fractures.
Where does the subclavius proximally attach?
It proximally attaches at the junction of the 1st rib and costal cartilage
Where does the subclavius distally attach?
It attaches distally to the inferior surface of the middle third of the clavicle.
What is the action of the subclavius?
It anchors and depresses the calvicle.
What is the proximal and distal attachment of the serratus anterior?
The proximal attachment is the external surfaces of lateral parts of ribs 1 - 8
The distal attachment is the anterior surface of the medial border of the scapula.
What is the nerve supply and action of the serratus anterior?
Nerve supply is the long thoracic nerve.
Action is to protract the scapula and hold it on the thoracic wall, rotates the scapula (glenoid fossa superiorly).
