262 MYOLOGY. 



Metatarsal Region. 



In this region we have the lumbricales and interossei as in the 

 anterior extremity, and also the extensor pedis brevis. 



EXTENSOR PEDIS BREVIS. 



{Extensor Pedis Accessorius.) 



(Fig. 85. d.) 



Situated in front of, and below the tarsal joint, it is small and 

 triangular in form, filling up the space between the converging 

 tendons of the extensor pedis and peroneus. 



Origin. — From the infero-anterior part of the astragalus ; it is 

 also attached to the cuneiform bones. 



Insertion. — It joins the tendons of the extensor pedis and 

 peroneus. 



Relation. — Underneath this muscle passes the anterior tibial 

 artery, giving off the perforafeg pedal branch. 



Action. — It assists slightly the extensors of the foot. 



Arrangement of the Fascia. 



We have already seen that the muscular system is invested by 

 an areolo-fibrous covering, which has been named the superficial 

 fascia. This covering varies very much in density in different 

 regions, and in some becomes blended with the srponeurosis of the 

 panniculus ; and generally where the muscles are braced by the 

 fleshy portion of the latter, the investing f&rrcia is more or less 

 rudimentary, as in the head and neck ; it is with difficulty 

 demonstrable as a separate structure in the latter. The tunica 

 abdominalis has been considered as an elastic development of the 

 investing abdominal fascia. 



DEEP FASCIA. 



The following may convey a general idea of the arrangement 

 of the deep or aponeurotic fasciae. Each muscle is more or less 

 completely covered by a fold of fascia, which forms a sheath 

 round it and its tendon ; it then passes to and covers another 



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