Is his muscle also a protector of his insides? Does his super-strength add to his protection? How about the toughness of his skin, is his skin hard? I couldn't imagine Jessica Jones would enjoy that, so I'm going to cross that one out. I just feel like the full extent of his unbreakable skin isn't entirely defined anywhere.

Its stated that adamantium is able to pierce his skin but as far as his internal organs go they are that of a normal humans as he has taken some damage that has hurt his internal organs and had to have emergency surgery to repair the damage.