CIRCULATORY APPARATUS. 8 1 



Insertion. Under surface of coccygeal vertebra. 

 Action. Depresses tail or carries it to one side. 

 Nerve . Coccygeal . 



SACRO-COCCYGEUS LATERALIS. 



Origin. Spinous processes of last lumbar vertebrae. 

 Insertion. Sides of coccygeal vertebrae. 

 Action. Carries tail to one side. 

 Nerve. Coccygeal. 



ISCHIO-COCCYGEUS . 



Origin. Internal face of sacro-sciatic ligament and sciatic 

 crest. 



Insertion. Last sacral and first two coccygeal vertebrae. 

 Action. Depresses whole tail. 

 Nerve. Coccygeal . 



CIRCULATORY APPARATUS. 

 PERICARDIUM. , 



A fibro-serous membrane enveloping the heart and favoring its 

 movement by its polished surfaces. Fibrous layer attached by its 

 apex to the sternum, from the fourth rib to the xiphoid appendix. 



By its base to the great vessels of the neck and continuous with 

 the fascia of the neck. 



Serous layer composed of a layer of flattened epithelium on a 

 basement membrane. It is composed of two divisions, a visceral 

 and parietal. The parietal layer is reflected on the fibrous sac, 

 and the visceral over the heart itself. Amount of fluid in sac, 

 very small. 



Blood supply from mediastinal arteries. 



Nerves from sympathetic. 



HEART. 



The heart is the propelling organ of the blood. It is a hollow 

 muscle placed in the thorax opposite the third, fourth, fifth and 

 sixth ribs, between and below the lungs. It is conoidal in shape, 

 10 inches long and 7^ inches wide. Weight, 6J Ibs. 



