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 action of the pectoralis major muscle quizlet?
Acting Alone, clavicular head flexes humerus and sternocostal head extends it from flexed position.
Where does pectoralis major insertion?
Insertion. The upper and lower fibers of pectoralis major insert to the crest of greater tubercle of the humerus. Upper fibers are more anterior and caudal on the crest, while posterior fibers twist on themselves and are more posterior and cranial than the upper fibers.
What is under the pectoralis major?
Beneath the pectoralis major is the pectoralis minor, a thin, triangular muscle. The pectoralis major’s primary functions are flexion, adduction, and internal rotation of the humerus.
What is the origin of the pectoralis major muscle quizlet?
The origin of the pectoralis major muscle includes the portion of the sternum adjacent to the costal cartilages of the first six ribs. The insertion of the pectoralis major muscle is the flat tendon 2-3 inches wide to the outer lip of the intertubercular groove of the humerus.
What is the origin of the pectoralis major muscle?
Attachments of Pectoralis Major Muscle: Origin & Insertion
Sternal head: sternum, upper costal cartilages (1-6), and the aponeurosis of the external oblique. a. Lateral lip of the intertubercular (bicipital) groove of the humerus.
What is the main action of the rectus abdominis muscle quizlet?
The rectus abdominis flexes the vertebral column in addition to compressing the abdominal wall. The other abdominal muscles compress the abdominal wall and laterally rotate the trunk.
Where is pectoralis major and minor?
The pectoralis minor lies underneath its larger counterpart muscle, pectoralis major. Both muscles form part of the anterior wall of the axilla region. Attachments: Originates from the 3rd-5th ribs and inserts into the coracoid process of the scapula.
Which of the following is an action of the latissimus dorsi muscle?
The latissimus dorsi is responsible for extension, adduction, transverse extension also known as horizontal abduction (or horizontal extension), flexion from an extended position, and (medial) internal rotation of the shoulder joint. It also has a synergistic role in extension and lateral flexion of the lumbar spine.
Which of the following are actions of the glenohumeral joint?
Acting in conjunction with the pectoral girdle, the shoulder joint allows for a wide range of motion at the upper limb; flexion, extension, abduction, adduction, external/lateral rotation, internal/medial rotation and circumduction. In fact, it is the most mobile joint of the human body.
