Photoshop :: CS6 - Measure Multiple Lines Of Image

I have Photoshop cs6 extended addition and was told Photoshop would work for the research application I need but so far I am finding it very difficult to do what I want.  Basically, I need to be able to measure multiple lines (the red ones in the screen shot) of an image precisely, and make sure that the lines I measure are documented so that they are actually visible (so not just with the ruler tool) on the screen and labeled. 

See image for example.  I need the lengths (converted with the 2 micrometer scale at the bottom of the image).  When I use the info, it gives me the lengths, but I can't save them, or look them up at a different time.  Also, when using the line tool, then doing the "record measurement" it does not give me the length of the line but insted acts like it is a thin rectangle and gives me a height (which does not seem to be the same as if I used the measurement tool and put it next to the line, which is an idea I have, but not as accurate) and a width.