Pectoral Region Flashcards
Where is the pectoral region?
Anterior chest wall. 4 muscles that exert force on upper limb: pectoralis major and minor, serratus anterior and subclavius
Pectoralis major
Most superficial
Pectoralis major attachments
Clavicular head originates from anterior surface of medial clavicle
Sternocostal head originates from anterior surface of sternum, the superior six costal cartilages and aponeurosis of external oblique muscle
Distal attachment of both heads is onto intertubercular sulcus of humerus
Pectoralis major function
Addicts and medially rotates upper limb and draws scapula anteroinferiorly
Clavicular head acts individually to flex upper limb
Innervation of pectoralis major
Lateral and medial pectoral nerves
Pectoralis minor
Lies under pectoralis major
Pectoralis minor attachments
Originates from 3-5th ribs and inserts into the coracoid process of scapula
Pectoralis minor function
Stabilises scapula by drawing it anteroinferiorly against the thoracic wall
Innervation of pectoralis minor
Medial pectoral nerve
Serratus anterior
Located laterally in chest wall, forms medial border of axilla region
Serratus anterior attachments
Consists of several strips which originate from the lateral aspects of ribs 1-8. They attach to costal (rib facing) surface of medial border of scapula
Serratus anterior function
Rotates the scapula allowing arm to raise over 90 degrees. Holds scapula against rib cage
Serratus anterior innervation
Long thoracic nerve
Subclavius
Located under clavicle running horizontally
Minor protection to underlying neurovascular structures
Subclavius attachments
Originates from junction of 1st rib and its costal cartilage
Inserts onto inferior surface of middle third of clavicle
