94 



THORAX 



ring to which the cusps of the right atrio-ventricular valve are 

 attached. These cusps will be examined when the right 

 ventricle is opened. 



The Septum Atriorum and the Fossa Ovalis. The inter- 



Right common carotid artery Sterno-thyreoid musc'e 

 Vagus nerve | | Sterno-hyoid muscle 



First ri 



Right lung 



Fifth rib and transverse pro 



cess of 5th thoracic vertebr; 



C 



Rignt bronchus. 



Right pulmonary artery. 



Superior vena cava. 



D 



Left atrium 



Fossa ovalis 



Valve of inferior 

 vena cava 



Head of tenth rib 



Inferior vena cava 



Eleventh thoracic vertebra 



Right crus of diaphragm 



Epiploic foramen 



Left renal vein 

 Right renal artery 



-B 



Vertebral artery 

 Right superior intercostal artery 

 - Right vertebral vein 

 ,-Sterno-clavicular interarticular disc 

 Right innominate vein 

 First costal cartilage 

 Left innominate vein 

 A 



Ascending aorta 

 Right lung 



Auricle of right atrium 

 C 



Fourth right costal cartilage 

 Right coronary artery 



- Fifth right costal cartilage 



Margin of atrio-ventricular 



orifice 



Opening of coronary sinus 



Right ventricle 



Right lung 



Eighth right costal cartilage 



Right hepatic vein 

 '-, Liver 



Right branch of portal vc 



- Bile duct 



Junction of superior and 



descending parts of 



duodenum 

 , Transverse colon 



Bile duct 



FIG. 46. Sagittal section and partial dissection of the upper part of the 

 trunk of a young Male Adult. The section is to the right of the median 

 plane along the line of the superior and inferior venae cavoe and it 

 passes through the right margin of the left atrium of the heart. The 

 atria were partially distended and the ventricles were contracted. 



A-A Plane of section of Fig. 47. 



B-B. 



C-C. 



D-D. 



atrial septum is a fibre-muscular partition which intervenes 

 between the right and left atria (Fig. 45). In the foetus it is 

 pierced by an obliquely directed foramen, the foramen ovale, 

 already referred to; and in the adult it is marked on the 

 lower and posterior part of its right side by a shallow depres- 



