Upper Limb Muscles of the Pectoral Region Flashcards
What are the three muscles of the pectoral region?
Pectoralis major, pectoralis minor and serratus anterior.
Where is the pectoralis major?
It is a superficial muscle and makes up most of the anterior wall of the axilla.
What are the two heads of the pectoralis major and their attachments?
Clavicular head, attaches to clavicle, and sternocostal head, attaches to sternum and ribs.
Where does the pectoralis major attach distally?
Lateral lip of intertubercular sulcus of the humerus.
What is the pectoralis major innervated by?
The lateral and medial pectoral nerves, derived from the brachial plexus: C5 and C6 clavicular head, C7, C8 and T1 sternocostal head.
What is the arterial supply of the pectoralis major?
Pectoral and deltoid branches of the thoracoacromial artery, anterior intercostal arteries, and perforating ranches of internal thoracic artery.
What is the action of the pectoralis major?
Adducts and medially rotates humerus, draws scapula anteriorly and inferiorly. The clavicular head flexes the humerus and sternocostal head extends it from the flexed position.
Where is the pectoralis minor?
Posterior to the pectoralis major. Forms part of the anterior wall of the axilla.
What are the proximal attachments of the pectoralis minor?
3rd-5th ribs near their costal cartilages.
What are the distal attachments of the pectoralis minor?
Medial border and superior surface of coracoid process of scapula.
What is the pectoralis minor innervated by?
Medial pectoral nerve (C8, T1).
What is the arterial supply of the pectoralis minor?
Pectoral and deltoid branches of the thoracacromial artery.
What is the action of pectoralis minor?
Stabilises scapula by drawing it inferiorly and anteriorly against the thoracic wall.
What are the proximal attachments of the subclavius?
The junction of the 1st rib and its costal cartilages.
What is the distal attachment of the subclavius?
The inferior surface of the middle third of the clavicle.
