Human head

In human anatomy, the head is at the top of the human body. It supports the face and is maintained by the skull, which itself encloses the brain. In human anatomy, the head is at the top of the human body. It supports the face and is maintained by the skull, which itself encloses the brain. The human head consists of a fleshy outer portion, which surrounds the bony skull. The brain is enclosed within the skull. The head rests on the neck, and the seven cervical vertebrae support it. The human head typically weighs between 5 and 11 pounds (2.3 and 5.0 kg) The face is the anterior part of the head, containing the eyes, nose, and mouth. On either side of the mouth, the cheeks provide a fleshy border to the oral cavity. The ears sit to either side of the head. The head receives blood supply through the internal and external carotid arteries. These supply the area outside of the skull (external carotid artery) and inside of the skull (internal carotid artery). The area inside the skull also receives blood supply from the vertebral arteries, which travel up through the cervical vertebrae. The twelve pairs of cranial nerves provide the majority of nervous control to the head. The sensation to the face is provided by the branches of the trigeminal nerve, the fifth cranial nerve. Sensation to other portions of the head is provided by the cervical nerves. Modern texts are in agreement about which areas of the skin are served by which nerves, but there are minor variations in some of the details. The borders designated by diagrams in the 1918 edition of Gray's Anatomy are similar but not identical to those generally accepted today.