Wow, that looks like you took a pretty good hit to the head! Good to hear you checked out fine. Taking a shot to the head like that, you never know how serious thing might be...
I keep some band-aids along with Neo Sporin in the tool box along with some tape bandage. I've cut myself working on the cars in the past, and just used some paper towels and duc tape to help stop the bleeding
Oh, and don't even remind me how hard that hood latch is and how sharp the corners of the hoods are
Steve