428 LABORATORY MANUAL OF HUMAN ANATOMY 



Each ductulus alveolaris with all its branches makes up a 

 lobule of the lung (lobulus pulmonis). The term " lobule" as 

 used by the pathologists includes several of these anatomical 

 lobuli. Note the central position of the terminal branch of the 

 A. pulmonis and the peripheral distribution of the roots of the 

 pulmonary veins in each lobulus pulmonis. 



Thoracic Portion of Sympathetic Nervous System. 



Remove the pleura parietalis from the sides of the vertebral 

 column and from the inner surface of the ribs. Dissect out the 

 thoracic portion of the sympathetic nervous system (pars tho- 

 racalis 8. sympathici). Study 



(a) Thoracic ganglia (ganglia thoracalia). 



How many are there? How are they located? 



(b) Great splanchnic nerve (N. splanchnicus major). 



How is it formed? Where does it leave the thorax? 

 Find 

 (ba) Splanchnic ganglion (ganglion splanchnicum) . 



(c) Small splanchnic nerve (N. splanchnicus minor). 



How is it formed? How does it leave the thorax? In 

 the abdomen it gives off a renal ramus (ramus renalis). 



(d) Lowermost splanchnic nerve (N. splanchnicus imus). 



The plexus aorticus thoracalis, plexus cardiacus, plexus coro- 

 narii, rami pulmonales, and plexus pulmonalis have been studied 

 already. 



Wall of Thorax from within. 



Examine the Mm. intercostales interni and the ligamenta 

 intercostalia interna from within. Clean, isolate, and study 



(a) Subcostal muscles (Mm. subcostales) . 



(b) External intercostal muscles (Mm. intercostales externi). 



These can be exposed from within by removing the ligamenta 

 intercostalia interna in one or two intercostal spaces. 



(c) Intercostal arteries from the aorta (Aa. intercostales). 



The rami posteriores can now be examined at their origins. 



(d) Highest intercostal artery from the subclavian (A. intercostalis su- 



prema). 



(e) Intercostal nerves (Nn. intercostales) = anterior rami of thoracic 



nerves (rami anteriores Nn. thoracalium) . 



Examine their .proximal portions. 

 (/) Intercostal veins (Vv. intercostales). 



Study carefully the differences in termination on the two sides. 

 (g) Azygos vein (vena azygos) (0. T. vena azygos major). (Cf. Fig. 

 205.) 



