Problem:
I am confused regarding the presence of valves in the superior vena cava.
The superior vena cava does not possess valves unlike inferior vena cava, which possesses Eustachian Valve.
Required:
Question: Where are Haversian valves present?
Question: Aren't they present at the opening of caval i.e., superior vena cava.
Question: Why is it said that there is absence of valves in superior vena cava?
Any ideas? Or better yet, pointers to places where this has already been answered?