- What is SA node???
- -------------------are the blood vessels that starts in capillaries and ends in capillaries.
- What is pacemeter?
- Only the veins and not the arteriesare provided with valves. Why?????
- Thearteries are deep seated in the body? why???
Your friends have answered all your questions correctly so please refer to them.
@Others:- We really appreciate your contribution to this forum, keep posting!!