ATTACHMENTS OF MUSCLES 123 



their points of attachment sternohyoid, sternomas- 

 toid. 



In describing a muscle we speak of its origin and 

 insertion, the former term meaning its more fixed 

 point or central attachment of the head, while the 

 latter means the movable point to which the force of 

 the muscle is directed and upon which it acts when 

 it contracts. However, the majority of muscles act 

 from either their point of origin or insertion. The 

 exceptions are the muscles of the face, which arise 

 from the bone and are inserted into the skin. 



It must be remembered that no single muscle can 

 perform a movement alone: It requires several mus- 

 cles, one set to fix the limb or part called fixation 

 muscles, and another to act upon the part to be 

 flexed, extended, abducted, etc. 



Tendons. Tendons when seen during life or in the 

 recent state are white, glistening, fibrous cords, of 

 different size and shape, some are long and short, 

 thick, rounded, and flattened; consist mostly of white, 

 fibrous tissue, very strong and non-elastic. Their 

 blood-supply is very scant. The smaller tendons not 

 showing a trace of blood. The nerve endings have 

 special terminations called neurotendinous spindles 

 or crgans of Golgi. The tendons are attached to the 

 belly of the muscle by one extremity; to the periosteum 

 of bone or perichondrium of cartilage by the other, 

 and are usually the part which is called the insertion. 

 However, some muscles have a tendon at either 

 extremity, as the biceps and triceps, and others present 

 two muscular bellies with a tendon between, as the 

 digastric muscle. 



Aponeuroses. These are similar in structure to 

 tendons; they are flat, white, fibrous membranes 

 attached by one extremity to the muscle and by the 

 other to the bone, cartilage, ligament, or skin as the 

 gluteus maximus muscle. They usually are associ- 

 ated with thin or thick flat muscles just beneath the 



