Structure and Composition - The human head consists of a fleshy outer portion and a bony skull. - The brain is enclosed within the skull, which is supported by the seven cervical vertebrae. - There are 22 bones in the human head. - The head typically weighs between 2.3 and 5 kilograms. - The face contains the eyes, nose, mouth, cheeks, and ears.

Blood and Nerve Supply - The head receives blood supply from the internal and external carotid arteries. - The external carotid artery supplies the area outside the skull. - The internal carotid artery supplies the area inside the skull. - The vertebral arteries also provide blood supply to the area inside the skull. - The cervical vertebrae support the blood supply to the head. - The head is primarily controlled by the twelve pairs of cranial nerves. - The trigeminal nerve provides sensation to the face. - The cervical nerves provide sensation to other parts of the head. - The distribution of nerves on the skin of the head has some minor variations. - The head is innervated by the ophthalmic, maxillary, mandibular, cervical plexus, and dorsal rami of cervical nerves.

Function - The head contains sensory organs such as the eyes, ears, nose, and tongue. - These organs function as a processing center for the body by relaying sensory information to the brain. - The head houses the brain, which plays a crucial role in processing information. - The central nerve cluster in the head allows humans to process information faster. - The function of the head is essential for various cognitive processes and overall body coordination.

Society and Culture - The front of the head, particularly the face, is the main distinguishing feature between individuals. - Human brains are predisposed to recognize and differentiate between faces. - Depictions of bigger heads in cartoons symbolize greater intelligence. - The head is a source of metaphors and metonymies in human language. - Headhunting, the practice of preserving a person's head after killing them, has been practiced across different cultures and regions.

Measurements - Biocular breadth: Distance from outer corners of the eyes (right and left ectocanthi) - Bitragion breadth: Breadth of the head from right tragion to left tragion (tragion is the cartilaginous notch at the front of the ear) - Glabella to back of head: Horizontal distance from most anterior point of the forehead between the brow-ridges (glabella) to the back of the head - Menton to back of head: Horizontal distance from tip of the chin (menton) to the back of the head - Sellion to top of head: Vertical distance from nasal root depression between the eyes (sellion) to the level of the top of the head