144 MUSCLE TISSUE 



Pectoralis Major. This arises from the inner half 

 of the anterior surface of the clavicle, the sternum, 

 from the upper six rib cartilages and from the anterior 

 sheath of the rectus and external oblique aponeurosis. 

 The fibers converge to be inserted by two tendons, 

 united along the lower margin, into the external 

 bicipital ridge of the humerus. 



Subclavius. This arises from the groove on the under 

 surface of the clavicle and recess between the conoid 

 and trapezoid ligaments: inserted into the junction 

 of the first rib with its cartilage between the fibers 

 of the costoclavicular ligament. 



Pectoralis Minor. This arises from three ribs near 

 their cartilages, usually the third, fourth, and fifth, 

 often the second, third, and fourth or fifth, and from 

 the intercostal aponeurosis; insertion, inner border and 

 upper surface of the coracoid process of the scapula; 

 a bursa is under its insertion. 



The linea alba is a narrow depression seen along the 

 middle line of the abdomen, extending from the tip of 

 the breast bone ensiform to the symphysis pubes. 

 It is formed by the union of the aponeuroses of the 

 oblique and transversalis muscles, which surround the 

 recti muscles and adhere to the fascia and skin. A 

 little below the midpoint of the linea alba is a scar 

 the result of the healed umbilical cord, called the 

 umbilicus (navel). 



The linea semilunaris is a depression seen on the outer 

 side of each rectus abdominis muscle, and corresponds 

 to the line of fusion of the aponeuroses of the oblique 

 and transversalis muscles, as they blend to pass in 

 front and behind the recti muscles to form the sheath 

 of the latter muscles. It extends from opposite the 

 ninth costal cartilage to the spine of the pubic bone. 



Lineae transversae are depressions seen along the recti 

 muscles, and correspond to the attachment of the 

 aponeuroses of the abdominal muscles to the rectus. 

 They are usually three one below the ensiform car- 



