The muscular system (part c). In this chapter, you will learn: Muscles crossing the shoulder joint, rotator cuff anatomy and function, movement at the glenohumeral joint, muscles crossing the elbow joint, muscles of the forearm, muscles of the forearm: anterior compartment, muscles of the forearm: posterior compartment,.and other contents. | 10 The Muscular System: Part C Muscles Crossing the Shoulder Joint Nine muscles cross the shoulder joint to insert on and move the humerus Muscles Crossing the Shoulder Joint Some originate off the scapula; others originate off the axial skeleton Three are prime movers of the arm Pectoralis major Latissimus dorsi Deltoid Actions include flexion, extension, adduction, abduction, and rotation of humerus Muscles Crossing the Shoulder Joint PLAY A&P Flix™: Deltoid PLAY A&P Flix™: Latissimus dorsi PLAY A&P Flix™: Pectoralis major Muscles Crossing the Shoulder Joint Four muscles are rotator cuff muscles Supraspinatus Infraspinatus Teres minor Subscapularis Reinforce the capsule of the shoulder Act as synergists and fixators Two additional muscles are synergists: coracobrachialis and teres major Muscles Crossing the Shoulder Joint PLAY A&P Flix™: Movement from the rotator cuff muscles (a) PLAY A&P Flix™: Muscles that cross the glenohumeral joint PLAY A&P Flix™: Movement from the rotator cuff muscles (b) PLAY A&P Flix™: Teres Major Rotator Cuff Anatomy and Function PLAY A&P Flix™: Supraspinatus PLAY A&P Flix™: Subscapularis PLAY A&P Flix™: Infraspinatus PLAY A&P Flix™: Teres minor PLAY A&P Flix™: Rotator cuff muscles Figure Clavicle Deltoid Sternum Pectoralis major Lateral head Long head Medial head Coracobrachialis Triceps brachii: Biceps brachii Brachialis Brachioradialis (a) Anterior view Rotator Cuff Anatomy and Function PLAY A&P Flix™: Axial muscles of the glenohumeral joint (a) PLAY A&P Flix™: Scapular muscles of the glenohumeral joint (a) Figure Supraspinatus* Spine of scapula (b) Posterior view Deltoid (cut) Greater tubercle of humerus Infraspinatus* Teres minor* Teres major Triceps brachii: Latissimus dorsi Humerus Olecranon process of ulna Lateral head Long head Anconeus * Rotator cuff muscles Rotator Cuff Anatomy and Function PLAY A&P Flix™: Scapular muscles of the glenohumeral joint (b) PLAY A&P Flix™: Axial muscles of the glenohumeral joint (b) | 10 The Muscular System: Part C Muscles Crossing the Shoulder Joint Nine muscles cross the shoulder joint to insert on and move the humerus Muscles Crossing the Shoulder Joint Some originate off the scapula; others originate off the axial skeleton Three are prime movers of the arm Pectoralis major Latissimus dorsi Deltoid Actions include flexion, extension, adduction, abduction, and rotation of humerus Muscles Crossing the Shoulder Joint PLAY A&P Flix™: Deltoid PLAY A&P Flix™: Latissimus dorsi PLAY A&P Flix™: Pectoralis major Muscles Crossing the Shoulder Joint Four muscles are rotator cuff muscles Supraspinatus Infraspinatus Teres minor Subscapularis Reinforce the capsule of the shoulder Act as synergists and fixators Two additional muscles are synergists: coracobrachialis and teres major Muscles Crossing the Shoulder Joint PLAY A&P Flix™: Movement from the rotator cuff muscles (a) PLAY A&P Flix™: Muscles that cross the glenohumeral joint PLAY A&P Flix™: Movement from the rotator .
