THE THORAX AND THORACIC VISCERA. 83 



Vertebral portion : 

 Right side. 

 Left side. 

 Intercostal portion : 



Pleural branches, (572). 

 Diaphragmatic branches, 583. (573) 

 Aberrans artery, 583-4. (573) 

 Intercostal nerves, 843-5. (825-6) 

 Upper intercostal nerves. 

 Lower intercostal nerves. 



Intercostal or posterior intercostal lymphatic glands, 696. (68 1) 

 Infracostales, or subcostals, 4223. (419) 



Origin. Insertion. Structure. Xerve-supply. Action. Relations. Endotho- 

 racic fascia. 



Open the cavities of the heart in the order and by the methods indicated, exposing the structures with- 

 in. The student should at the same time dissect the heart of an ox or the heart of a sheep, and de- 

 monstrate the action of the valves in the manner indicated. 



The heart : 



Four cavities, 965-6. (9423) 

 Venous side. 

 Arterial side. 

 The right auricle, 966-78. (943-4-5) 



Make an incision through the auricular wall between the superior and inferior venae cavae, 

 and from the middle of this incision to the end of the appendix, exposing the interior of the 

 auricle. 



Endocardium. 



Sinus venosus, or atrium. Auricular appendix. 



Openings : 



Superior vena cava. 



Inferior vena cava. 



Auriculo-ventricular opening. 



Coronary sinus. 



Foramina Thebesii. 

 Superior caval opening. 

 Inferior caval opening. Eustachian valve. 

 Coronary sinus. Valve of Thebesius. 

 The foramina Thebesii, vena Galeni. 

 Cavity of the right auricle. 

 Fossa ovalis. Annulus ovalis. 

 Tubercle of Lower. 



Introduce the end of the blowpipe into the right ventricle by passing it through the pulmonary 

 artery and between the pulmonary semilunar valves. Place a ligature around the commence- 

 ment of the pulmonary artery, then inflate the ventricle. The action of the tricuspid valve 

 and the closing of the auriculo-ventricular opening can be readily demonstrated. 



Open the right ventricle by two incisions as follows : Make a vertical incision through the 

 ventricular wall, about a quarter of an inch to the right of the anterior interventricular groove 

 and parallel with it, beginning above at the conus arteriosus and passing downward and 

 around the end of the ventricle ; make a transverse incision through the upper part of the 

 ventricular wall, extending from the upper end of the first incision to the right border of the 

 ventricle, half an inch below and parallel with the auriculo-ventricular groove. Exercise 

 care to divide the ventricular wall only, and not to injure the structures within. 



Right ventricle, 968-9. (945-6-7) 

 Form. Conus arteriosus. 

 Inner surface, or body ; ridges, bands, columns : 



Columnae cerneae ; musculi papillares, moderator band. 

 Musculi papillares : 

 Anterior. 

 Right. 

 Posterior. 



