Muscles of the pectoral region Flashcards
Whatis pectoralis major?
What are its attatchments?
Large fan shaped muscle in the pectoral region
Originates from Clavicular head and sternocostal head (anterior surface of sternum)
Attaches into the intertubercular sulcus of the humerus
What is the function of pectoralis major?
What innervates pectoralis major?
Adducts and medially rotate the upper limb.
draws scapula anteroinferiorly
lateral and medial pectoral nerves
What is pectrolais minor?
What innervates it?
Triangular shaped muscle that lies underneath pec major to form the anterior wall of the axilla.
Median pectoral nerve
Where does pectoralis minor attatch?
What is the function of this muscle?
Originates from 3-5th ribs, inserts into the coracoid process of the scapula
Stabilises scapula by drawing it anteroinferiorly against the thoracic wall
What is serratus anterior?
What innervates it?
Lateral lying muscle that forms the medial border of the axilla
Long thoracic nerve
What are the attachments of serratus anterior
What are its functions?
The muscle is made up of several strips arising from ribs 1-8. They attach to the medial border of the scapula
Rotate the scapula, allow arm to be raised above 90 degrees. hold the scapula against rib cage
What is the subclavius muscle?
What innervates it?
Small muscle located underneath the clavicle, running horizontally. It affords some minor protection to the underlying neurovascular structures.
Subclavius nerve
Where does the subclavius attatch?
What is the function of the subclavious?
Originates from the 1st rub and inserts into the middle third of the clavicle
Anchors and depresses clavicle
What causes winging of the scapula
Damage to the long thoracic nerve, paralyses serratus anterior. commonly occurs in traction injuries where the upper limb is violently stretched
