Muscles of the Pectoral Region Flashcards
What muscles are in the pectoral region
Pectoralis major
Pectoralis minor
Serratus anterior
Subclavius
Which is the most superficial muscle in the pectoral region
Pectoralis major
What are the heads of pectoralis major
Sternal head
Clavicular head
Where is the insertion of both heads of pectoralis major
Intertubercular sulcus of the humerus
Where does the clavicular head of pectoralis major originate
From the anterior surface of the medial clavicle
Where does the sternocostal head of pectoralis major originate
Anterior surface of the sternum
Superior 6 costal cartilages
Aponeurosis of the external oblique muscle
What is the function of pectoralis major
Adduction of the upper limb
Internal rotation of the upper limb
Draws the scapula anteroinferiorly
What nerves innervate pectoralis major
Lateral pectoral nerve
Medial pectoral nerve
Where does pectoralis minor lie
Underneath pectoralis major
Which muscles form the anterior wall of the axilla
Pectoralis major
Pectoralis minor
Where does pectoralis minor originate
From 3-5 ribs
Where does pectoralis minor insert
Coracoid process of the scapula
What is the function of pectoralis minor
Stabilises the scapula
Draws it anteroinferiorly against the thoracic wall
What nerves innervate pectoralis minor
Medial pectoral nerve
Which muscle forms the medial border of the axilla
Serratus anterior
Where does serratus anterior originate
Lateral aspects of ribs 1-8
Where does serratus anterior insert
Costal surface of the medial border of the scapula
What is the function of serratus anterior
Rotates the scapula (allowing the arm to be raised over 90 degrees)
Holds scapula against the ribcage
Which nerves innervate serratus anterior
Long thoracic nerve
Where is subclavius located
Directly underneath the clavicle
Where does subclavius originate
From the junction of the 1st rib and its costal cartilage
Where does subclavius insert
Inferior surface of the middle third of the clavicle
What is the function of subclavius
Anchors and depresses the clavicle
Also provides minor protection to underlying neurovascular structures
What nerves innervate subclavius
Nerve to subclavius
What occurs with damage of the long thoracic nerve
Winging of the scapula
What is the most common cause of long thoracic nerve injuries
Traction injuries
