ANATOMY IX A NUTSHELL. 



497 



lymphatic vessels to prevent the backward how of the lymph. They are formed 

 by folds of the lining membrane and their position is marked by a circular con- 

 striction. 



The thoracic duct has three coats, (1) an internal or endothelial, (2) a 

 middle of white connective tissue, (3) an external of areolar tissue. There 

 are numerous valves in the thoracic duct especially at its upper end, and there 

 is a pair at its termination to prevent blood from entering the duct. 



The kelations of the thoracic duct are: 



.Behind. — (1) The body of the second lumbar vertebra, (2) Bodies of the 

 seven lower thoracic vertebra 1 , (3) Anterior common ligament, (4) Lower 

 right intercostal arteries. (.1) Vena azygos minor, ((>) Vena azygos tertius, (7) 

 Upper thoracic vertebrae. 



Ox Right Side. — (1) Right cms of the Diaphragm, (2) Vena azygos major, 

 (3) Right pleura, (4) (Esophagus. 



In Front. — (1) Aorta and right cms of the Diaphragm, (2) Pericardium, 

 (3) (Esophagus, (4) Arch of the aorta, (5) First portion of subclavian artery. 



On Left Side. — (1) Aorta, (2) Left pleura, (3) Vena azygos minor. (4) 

 Vena azygos tertius. 



PLATE CCLXIII. 



ORBITAL PROCESS 

 ETHMOIDAL SURFACE 



SUPERIOR MEATUS 



SPHENO-PALATINE 



FORAMEN^ 



SPHENOIDAL PROCESS 'J<C<\ \ 



'fyli I > ; MEA 



/o\V < v 



ORBITAL SURFACE 



MAXILLARY SURFACE 



(MC -* TUS c, *|fc-MAXILURY PROCESS 



INF. TURBINATED ft, .' s /^ _j 



.x j\\ INFERIOR / = 

 MEATUS A 

 ARTICULATES WITH " / 



ffWm 



HORIZONTAL i PLATE 

 ARTICULATES WITH VOMER AND OPPOSITE HONE 



The Lateral View of the Palate Bone. 



The receptaculum chyll is the beginning of the thoracic duct. It isan irregu- 

 lar, sacculated and fusiform sac. It has no valves in it. and its dimensions are 

 one and a half by three-quarters of an inch. It is situated in fronl of tin" sec- 

 ond hunbai' vertebra. 



A lymphatic node consists of an outer pari called a capsule, which is made 

 of white fibrous tissue and a small amount of smooth muscular tissue. From 

 the inner surface of t his capsule trabecular pass towards the center of the node. 



