What is the definition of a pectoralis major?
a : a larger one that arises from the clavicle, the sternum, the cartilages of most or all of the ribs, and the aponeurosis of the external oblique muscle and is inserted by a strong flat tendon into the posterior bicipital ridge of the humerus. — called also pectoralis major.
What is the action of the pectoralis major?
The function of the pectoralis major is different for its different heads. The clavicular head flexes the humerus, and the sternocostal head adducts the humerus. As a whole the action is to adduct and medially rotate the humerus. It also draws the scapula anteriorly and inferiorly.
Why is the pectoralis major important?
These large muscles help you move your shoulder. These muscles help pull your arm across the front of your body. Injury to the pectoralis major can cause shoulder pain and limit your ability to use your arm fully. The pectoralis major is superficial, making it easy to see and palpate (feel).
What does the pectoralis major muscle do quizlet?
What does the pectoralis major muscle do? It adducts the arm.
What kind of muscle is the pectoralis major?
Pectoralis major is a thick, fan-shaped muscle contributing to the thoracobrachial motion. It consists of a clavicular part and a sternal part, both converging to a flat tendon that inserts on the humerus. It’s innervated by both medial and lateral pectoral nerves.
Where is the pectoralis major muscle located quizlet?
The pectoralis major muscle is a large muscle in the upper chest, fanning across the chest from the shoulder to the breastbone. The two pectoralis major muscles are the muscles that create the bulk of the chest.
What action does the pectoralis minor perform?
Function. The primary actions of this muscle include the stabilization, depression, abduction or protraction, internal rotation and downward rotation of the scapula.
What is the pectoralis major origin?
Pectoralis major muscle
| Origin | Clavicular part: anterior surface of medial half of clavicle Sternocostal part: anterior surface of sternum, Costal cartilages of ribs 1-6 Abdominal part: Anterior layer of rectus sheath |
|---|---|
| Insertion | Crest of greater tubercle of humerus |
What is the origin of the pectoralis major quizlet?
Origin: Ribs 3-5 near costal cartilages, Inserts medial border and superior surface of coracoid process of scapula, innervation Medial Pectoral nerve, Fx, Stabilizes scapula by drawing it inferiorly and anteriorly against thoracic wall.
Where is pectoralis minor and major?
pectoralis muscle, any of the muscles that connect the front walls of the chest with the bones of the upper arm and shoulder. There are two such muscles on each side of the sternum (breastbone) in the human body: pectoralis major and pectoralis minor.
What are the parts of the pectoralis major?
The pectoralis major has a broad origin, based on which it is divided into three parts: clavicular part, sternocostal part and abdominal part. All three parts converge laterally and insert onto the greater tubercle of humerus.
What does the pectoralis major do quizlet?
Pectoralis Major Function: Adducts and medially rotates the humerus, and draws the scapular anteroinferiorly. On its own the clavicular head flexes the humerus , and the sternocostal head extends it.