ripped my hand

Wow, looks awesome o.O

I see you've asked for critique and not recieved much so I hope you don't mind me critiquing ^-^

I think it needs to look a little deeper, the tendons a little more red.
The fake blood around the outside is too blocky, use red eyeshadow or blush, it makes it fainter around the edge so it doesn't stand out as much
Also maybe use some purple around the outer edge to make it look bruised and stuff.

For making fake wounds I'd suggest using images of the actual wounds for reference, but if that's too gross watch a few tutorials on YouTube, I say a few because different people have different techniques and tips so you can use the ones that suit you best.

Again though, you already have it looking awesome, if it's just for haloween or something it's fine as it is ^-^