supraspinatus
lateral rotation
The rotator cuff muscles are referred to occasionally as the SITS muscles. The Supraspinatus, Infraspinatus, Teres minor and the subscapularis. The Supras. originates on the scapula and inserts on the humerus. The Infras. originates on the scapula and inserts on the humerus(greater tubercle. The Teres minor originates on the scapula and inserts on the humerus. The Subscapularis originates on the scapula and inserts on the humerus(lesser tubercle). The function of this muscle group is to stabilize the shoulder joint. Hope this helps.
Biceps
You have the pectoralis major muscle in the chest wall. It arise from the sternum and the clavicle. It is inserted on the lateral part of the bicipital groove.
The subscapularis muscle originates on the anterior surface of the scapula and inserts on the proximal anterior humerus. Its function is to rotate the head of the humerus medially.
The biceps brachii muscle.
The triceps originates on the scapula and proximal humerus and inserts on the olecranon process. The muscles has three heads (hence its name) so it has multiple origins.
Latissimus dorsi
Latissimus dorsi
The greater tuberosity of the humerus forms the lateral contour of the shoulder. The supraspinatus muscle attaches at the greater tuberosity.
The brachialis muscle originates on the distal anterior humerus and insert at the coronoid process. The function of the brachialis is flexion at the elbow.
Because the latissimus dorsi origin is from the back and it inserts on the humerus. It doesn't cover the abdomen at all.