DISSECTION OF THE THORAX 



411 



Ascertain exactly the distribution of the pericardium at the 

 base of the heart and about the great vessels. 



Thymus. 



The appearances will vary according to the age of the individ- 

 ual. If the cadaver be that of a child, study the following : 



(a) Right and left lobes (lobi dexter et sinister}. 



(b) Central tract (tractus centralis). 



(c) Lobules of thymus (lobuli thy mi). 



Ductusf dexter- 

 Cuvieri 1 sinister .- 



V. cardinalis _ 

 dextra 



FIG. 205. 



V. jugularis extern 

 V. jugularis interna. 



V. subclavia 



sinistra V. subclav 

 dextra 



V. anonyma sinistra 



V. cava superior '" 

 Sinus coronarius cordis---'" 



V. cardinalis 

 sinistra 



V. azygosj 



V. hemiazygos 



Diagrams of A, the primitive anlage of the venous system of the body and B, the formation of the 

 system of the v. cava superior. (Rathke's schema with slight alterations by F. Hochstetter. ) (After 

 Toldt, Anat. Atlas, Wien, 1900, 2 Aufl., p. 563, Fig. 939.) 



Great Veins of Thorax and their Tributaries. (Vide Fig. 205.) 



Remove the thymus or the fat-body representing it; dissect 

 out the great veins of the thorax. Clean and study 



(a) Superior vena cava (V. cava superior). 



(aa) Right and left innominate veins (Vv. anonymae dextra et 

 sinistra). 



(aaa) Inferior thyreoid veins (Vv. thyreoideae inferiores). 



(aab) Lowest thyreoid vein (V. thyreoideae ima). 



(aac) Thymic veins (Vv. thymicae). 



(aad) Pericardiac veins (Vv. pericardiacae) . 



(aae) Superior phrenic veins (Vv. phrenicae superiores). 



(aaf) Anterior mediastinal veins (Vv. mediastinales ante- 



rior es}. 



(aag) Anterior bronchial veins (Vv. bronchioles ante- 



rior es). 

 (aah) Vertebral vein (V. vertebralis) . 



(1) Deep cervical vein (V. cervicalis profunda). 

 (aai) Internal mammary vein (V. mammaria interna). 



