Question

How is sinus venosus formed in Amphibia?

Answer 1

The sinus venosus is present in the heart of the lower organisms like the amphibians. It is the membrane which is formed in the cavity of the heart. This membrane presents in the atrium region between the two vena cavae. The structure develops to form a smooth membrane in the right ventricle to form sinus venarum. This structure, later on, develops to form SA node and coronary sinus.