The opening of auricles and ventricles on the right side is guarded by

Blood to the heart is brought by the venous system by:

Where is the tricuspid valve located?

Choose the incorrect statement about the human heart $:-$

During human fetal development, the pulmonary artery is connected to the aorta by a narrow duct called the ductus arteriosus. What is this structure called after it closes and becomes a fibrous remnant in an adult?

Provide the definition/explanation for the following heart valves:
$(1)$ $AV$ valve (Tricuspid)
$(2)$ Mitral (Bicuspid) valve