The word for head in Russian is голова. But the word for the major bone structure that makes up head, or the skull, is the череп. This word declines this way:

The skull, like all the other bones, is there to protect the organs behind it and in this case the brain. The skull is made up of minor bones connected by sutures and joints. The two major parts of the skull are the mandible (the jaw) which is part of the facial bones and the cranium. In English we have a lot of terms that incorporate the word skull. The word numbskull is an example which translates into Russian as тупица. We all know someone who has acted like a numbskull once in a while. Usually a numbskull is someone who did not quite think something through and did something or said something that was stupid or mean. I know when I have to work on a school project with a group there might be someone that isn’t quite competent and we have to talk to that person to help them pick up the slack.