LABORATORY MAXUAL OF HUMAX AXATOMY 



minutes, then placed in cold water and dissected. Other fresh 

 hearts should he distended under pressure, fixed and hardened 

 in fiVe or ten per cent, formalin for several days : windows may 

 then he cut out in various ways in order to display internal 

 Bwudiires. 



Follow the course of the muscle Bundles (a) in the atria, (b) 

 in the ventricles. Study the mode of formation of the vortex of 

 the heart (vortex cordis). Look up the articles by Ludwig. J. B. 

 MaeCaDum. and Betzger on the distribution of the heart-mnscle 

 fibres. 



.fibrous I?HI|* of Heart (Annan fibrosi). 



Cut away the atria with scissors. Examine the relative posi- 

 tions of the orifices at the base of the ventricular portion of the 

 heart Stud 



fbrc&ws tfarter). around 



Separate the ramus dexter from the ramus sinister of the A. 

 puhnonalis and reflect each lateralward. Expose the trachea 

 and bronchi thoroughly by drawing the areas aortae aside and 

 ving the bronchial lymph-glands (lymphoglandulae bran- 



chides) in the angle of bifurcation of the trachea. Examine 

 carefully the relations of the trachea. Xote the level of the bifur- 

 cation (bifurcatio tracheae) into the right and left bronchus 

 (bronchus [dexter et sinister]). Look for the broncho-oesopha- 

 geal muscle (If. broneho-oesophageus). 



Posterior Mcdiastinal Cavity and its Contents. 



To open the posterior mediastinal cavity (cmum media- 

 stinale posterius) (O. T. posterior mediastinum), make a vertical 

 cat through the pericardium along the oesophagus and reflect the 

 pericardium lateralward. Look for the pleuro-oesophageal mus- 

 cle (M. pleuro-oesophageus), extending across the aorta de- 

 scendens from the oesophagus to the left pleura. In the cavmn 

 mediastinale posterius dissect out and study thoroughly the rela- 

 tions of the following: 



