ANATOMY IN A NUTSHELL. 



479 



behind this abnormal extension of the tunica vaginalis, in this case there arc 

 three layers of peritoneum in front of the hernia, two of them arc from the 

 tunica vaginalis and the third from the sac around the hernia. In this form of 

 hernia the tunica vaginalis testis may pass up as high as the internal abdominal 

 ring. 



4. Encysted hernia. This is the rarest of all forms of congenital hernia 

 and is formed by the hernia pushing the closing septum of the internal abdom- 

 inal ring as a diverticulum into the unclosed tunica vaginalis. 



PLATE CCLVII. 



MUSCLES 

 A-EXT. PTERYGOID 

 B-INT. PTERYGOID 

 C-TEMPORAL. 

 D-BUCCINATOR 



GROOVES LIG'MTS.LTr. 



J-MANDIBULAR SPINE. 



K- MANDIBULAR FORAMEN 



L-SPHENO-MAND'R LIG'MT. 



M-STYLO-MAND'R LIG'WT 

 E-SUP. CONSTRICTOR. N-GROOVE FOR SUBMAY'Y GLAND. 

 F-MYLO-HYOID. O-GR00VE FOR SUBLING'L GLAND 



G-GENI0-HYO-GL0SSUS.P-MYLO-HYOID GROOVE 

 H-GENIO-HYOIDEUS. 3-MYLO-HYOID RIDGE. 



R-CAPSULE. 





Internal Surface of Inferior Maxillary Bone. 



LESSON CLV. 



Veins. 



Every vessel that Leaves the heart is called an artery, and every vessel thai 

 enters the heart is called a vein. Arteries, as a rule, carry pure blood, while 

 the veins carry impure blood bu1 there are exceptions to each of these cases. 

 The pulmonary arteries carry impure blood while the pulmonary veins carry 

 pure blood. As a general thing veins have valves and arteries do not have 

 valves, but there arc exceptions to tins rule, for the pulmonary artery has a 

 valve and the pulmonary veins do not have valves. Veins, like arteries, have 

 three coats, and the middle coai like that of the artery lias sympathetic fibers 

 around it but not so well developed as in the arteries. 



