<prompt> Which of the following does not directly drain into right atrium-Great cardiac veinAnterior cardiac veinThebasian veinVenaecordis minimi  <response>: Ans. is a i.e., Great cardiac vein o Great cardiac vein does not directly drains into right atrium. It drains into coronary sinus, which in turn drains into right atrium.Veinous drainage of heart1. Coronary sinus: Opens into right atrium and has following tributries : i Great cardiac vein, ii Middle cardiac vein, iii Posterior vein of left ventricule, iv Small cardiac vein, v Oblique vein of left atrium and vi Sometimes right marginal vein.2 Anterior cardiac vein : Opens into right atrium.3. Venae cardis minimi thebasian veins : Open into right atrium.4. Right marginal vein : More often opens into right atrium but sometimes into coronary sinus. 