THE FROG — A REPRESENTATIVE VERTEBRATE 



403 



Fle^coT 

 digitorura 

 brevis 



Pyrifo 

 Seraime-mtr a.Tio sus 



eltoideiAS 



Forearm 

 flexors 



and 

 xte,nsors 

 Triceps 

 Pectora.liS 

 orsalis scapulae 

 atissixnus d.orsa.p. 

 n6issimu.s dorsa.e 

 Oblic[u.us e-Dcternus 



tuS aixiominis 



ctu-S a.nticu.S 



stu.^ intcrriTx 

 Vastus e.xtcrnu.s 



Sartor 



lUofitu., 



Qracil 

 minor 



Gastrocnemius 

 Tibialis a.nt 

 Peroncus j^g^ais 



Abductor brevis 



^^Adductor 



ma^nuS 



Adductor lon^uS 



racilis major 



ibialis posticus 



Tarsalis 

 posticus 



Figure 21.7. Superficial skeletal muscles of the frog in a dorsal (left side of figure) 

 and a ventral (right side) view. 



pleuroperitoneal cavity containing the other visceral organs. The coelom 

 is hned with a thin layer ot epithelium. The internal organs have pushed 

 into the coelom (Fig. 21.8) and are covered by a layer of coelomic 

 epithelium called the visceral peritoneum. The visceral peritoneum is 

 continuous with the parietal peritoneum lining the body wall by way 

 of thin, double-layered mesenteries which support the internal organs. 

 Blood vessels and nerves pass through the mesenteries in gomg from 

 the body wall to the visceral organs. Relations in the pericarc^ial cavity 

 are much the same, but mesenteries are absent in the adult. 1 he 

 coelomic epithelium here is called the visceral and parietal pericardium. 



