Multiple choice Which of the following structures is present in the right ventricle of mammals? Orifice of the superior vena cava Orifice of the inferior vena cava Orifice for the coronary sinus Orifice of the pumonary trunk Reveal answer Fill a bubble to check yourself D Correct answer Explanation Orifice of the pumonary trunk is the opening between the pulmonary trunk and the right ventricle of the mammalian heart.