Torus aorticus involves:

Ans. d (Right atrium). (Ref. Grey, Anatomy, 36th ed., 644)Torus aorticusAnterosuperior part of septal wall of right atrium bulges to some degree into the atrial cavity as torus aorticus. It is caused by proximity of right posterior aortic sinus and cusp.Torus auditoryThe postero-inferior wall of external meatus occasionally presents a smooth to roughened longitudinal elevation, known as auditory torus.Torus mandibularisAbove myelohyoid line, the bone medial to roots of molar teeth is sometimes developed into a rounded ridge called torus mandibularis.Torus palatineIntermaxillary sutures are sometimes raised forming a longitudinal midline ridge.Torus maxillarisIt is occasionally present on the alveolar process spanning the palatal aspect of subcervical roots of upper molar teeth.