VEINS. 



the left side the second to fourth form a trunk (left superior 

 intercostal) , which runs forward on the left side of the aortic 

 arch to the left innominate. The fifth to eighth join the supe- 

 rior azygos minor, and the ninth to eleventh the inferior. [873] 



Innominate Veins. Both are formed by the union of the 

 subclavian and internal jugular behind the sternal end of the 

 clavicle ; descending to the lower border of the first right cos- 

 tal cartilage, both unite, forming the superior vena cava. The 

 right innominate receives the right lymphatic duct and the 

 vertebral, internal mammary, inferior thyroid, and first pos- 

 terior intercostal veins. The left innominate receives the 

 thoracic duct and the vertebral, internal mammary, inferior 

 thyroid, superior and first posterior intercostal, thymic, 

 bronchial, mediastinal and pericardial veins. [873] 



The internal mammary veins have the same course and 

 branches as the artery; they join the innominate. The ver- 

 tebral veins correspond to and accompany only the extra- 

 cranial parts of the arteries. They drain the intraspinal 

 plexuses and adjacent structures of the neck, and receive the 

 anterior and posterior vertebral (deep cervical) veins from 

 plexuses on the front and back of the spine. The inferior 

 thyroid drains the isthmus and corresponding lateral lobe of 

 the gland; descending in front of the trachea, the left vein 

 joins the left innominate, and the right vein the junction of 

 the innominates; both veins may unite in one trunk. [874] 



Subclavian Veins. Continuing the axillary at the outer 

 border of the first rib, each runs below and in front of its artery, 

 and in front of the Scalenus anticus; it joins the internal jug- 

 ular behind the sternal end of the clavicle, forming the in- 

 nominate. It receives the external jugular. [877] 



LYMPHATICS. 



Glands. The parietal glands consist of the following groups: 

 intercostal, lying in the posterior ends of the intercostal spaces ; 

 internal mammary (sternal) , lying at the anterior ends of the 



[135] 



