This human head anatomy diagram depicts the various parts of the human head. In human anatomy, the head is the upper portion of the body that includes the skull, its coverings, contents, and the lower jaw. The atlas, the first cervical vertebra, connects it to the spinal column, and the muscles, blood vessels, and nerves that comprise the neck connect it to the trunk of the body. Other than humans, the term is also used to describe the anterior or forepart of animals. The human head is more than a nuisance that causes headaches. It is a complex anatomical structure that can weigh up to five kilograms and rests on the bony skull and, as a result, the neck.