which area of anatomy most helpful to nursing student.

Which area of anatomy is most helpful for nursing students as they go thru the actual RN program? Skin? Endocrine?
I want to get fluent with a certain area that will be most helpful in later studies, basically re-read the textbook chapter an extra book on that subject as well.

What about actually being a nurse? any area of anatomy that is more helpful to know about than others?

Thanks.