ABDOMEN AND PELVIS 511 



Excise a portion of the abdominal part of the ureter. Make 

 a dissection of its different coats, using a loop. 



(a) Adventitious coat (tunica adventitia). 



(b) Muscular coat (tunica muscularis) . 



(ba) External layer (stratum externum). 



(bb) Middle layer (stratum medium), 

 (be) Internal layer (stratum internum). 



(c) Mucous coat (tunica mucosa). 



(ca) Mucous glands of ureter (Gl. mucosae ureteris). 



MUSCLES, VESSELS, AND NERVES. 



Diaphragm (Diaphragma). 



Strip the peritoneum from the under surface of the dia- 

 phragm, preserving carefully the vessels and nerves which 

 ramify on its under surface. Review the development of the 

 diaphragm. How do you explain a partial innervation by a 

 cervical nerve ? Make a careful study of the architecture of this 

 muscle, noticing carefully the form, position, origin, insertion, 

 and action of its different parts. (Vide Spalteholz, Fig. 314.) 



(a) Lumbar part (pars lumbalis). 



(aa) Medial crus (crus mediale). 



(ab) Intermediate crus (crus intermedium). 



(ac) Lateral crus (crus laterale). 



(b) Costal part (pars costalis). 



(c) Sternal part (pars sternalis). 



(d) Aortic opening (hiatus aorticus). 



(e) Oesophageal opening (hiatus oesophageus). 



(f) Central tendon (centrum tendineum). 



(g) Opening for vena cava (foramen venae cavae). 



(h) Medial lumbocostal arch (arcus lumbocostalis medialis [Halleri]) 



(0. T. ligamentum arcuatum internum). 

 (i) Lateral lumbocostal arch (arcus lumbocostalis lateralis [Halleri]) 



(0. T. ligamentum arcuatum externum). 



Examine the structures passing through the hiatus oesopha- 

 geus, the hiatus aorticus, and the foramen venae cavae. What is 

 the weak spot of the diaphragm? Where is Larrey's space? 



Abdominal Aorta and Inferior Vena Cava. (Vide Spalteholz, Figs. 



463, 499.) 



Clean these two vessels, avoiding injury to the truncus sym- 

 pathicus. The branches of the aorta will not be given in detail 

 where they have already been met with in earlier dissections. 



