VAN 121: Veterinary Gross Anatomy-II (2+2)

RIGHT ATRIUM 

Dissection

• Lay open the cavity of the right atrium by making an incision from the posterior venacava to the appendix and another through the anterior venacava to join the previous one.
• Note in the interior the intervenous crest projecting from the dorsal wall. Below the opening of the posterior venacava is the coronary sinus the opening of the great cardiac vein guarded by a small fold of endocardium, the coronary valve.
• The fossa ovalis is a depression in the interatrial septum at the point of entrance of the posterior venacava.
• In the appendix, note the musculi pectinati, which are muscular coloumns crossing in various directions and these muscular ridges terminate at the crista terminalis which corresponds to the sulcus terminalis externally.