THE NECTURUS 45 



External Jugular 



Turn the animal on its back and expose the base of the 

 gills where the skin is already removed. The large external 

 jugular sinus is exposed paralleling the external carotid. 

 Follow it posteriorly to where it is joined by the internal 

 jugular and the subclavian. It enters the ductus Cuvieri. 

 Anteriorly it branches and breaks up into several smaller 

 vessels that supply the nose, eye, oral cavity, and the 

 anterior part of the jaw. The enlarged base of the 

 external jugular forms the jugular sinus. 



Internal Jugular 



Examine the roof of the mouth and locate the roots of 

 the aorta. The internal jugulars are dorsal to these and 

 follow the roots anteriorly. They return the blood from 

 the roof of the mouth and brain to the anterior cardinal. 



Subclavian Vein 



Remove the skin from the back of the front limb and 

 locate the brachial branch of the subclavian. Trace it to 

 where it enters the subclavian. At the shoulder region, it 

 is joined by the cutaneous vein. The subclavian enters the 

 anterior cardinals along with the jugulars. 



ARTERIAL SYSTEM 

 The arterial system is made up of the following parts: 



Heart and truneus arteriosus 

 Afferent vessels: first afferent artery 



second afferent artery 



third afferent artery 

 Efferent vessels: first efferent artery 



second efferent artery 



third efferent artery 





