A head is the part of an

organism An organism is any life, living thing that functions as an individual. Such a definition raises more problems than it solves, not least because the concept of an individual is also difficult. Many criteria, few of them widely accepted, have be ...

which usually includes the ears,

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

forehead In human anatomy, the forehead is an area of the head bounded by three features, two of the skull and one of the scalp. The top of the forehead is marked by the hairline, the edge of the area where hair on the scalp grows. The bottom of the fo ...

, cheeks,

chin The chin is the forward pointed part of the anterior mandible (List_of_human_anatomical_regions#Regions, mental region) below the lower lip. A fully developed human skull has a chin of between 0.7 cm and 1.1 cm. Evolution The presence of a we ...

, eyes, nose, and

mouth A mouth also referred to as the oral is the body orifice through which many animals ingest food and animal communication#Auditory, vocalize. The body cavity immediately behind the mouth opening, known as the oral cavity (or in Latin), is also t ...

, each of which aid in various sensory functions such as

sight Visual perception is the ability to detect light and use it to form an image of the surrounding Biophysical environment, environment. Photodetection without image formation is classified as ''light sensing''. In most vertebrates, visual percept ...

, hearing, smell, and

taste The gustatory system or sense of taste is the sensory system that is partially responsible for the perception of taste. Taste is the perception stimulated when a substance in the mouth biochemistry, reacts chemically with taste receptor cells l ...

. Some very simple animals may not have a head, but many bilaterally symmetric forms do, regardless of size. Heads develop in animals by an

evolution Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...

ary trend known as cephalization. In bilaterally symmetrical animals,

nervous tissue Nervous tissue, also called neural tissue, is the main tissue component of the nervous system. The nervous system regulates and controls body functions and activity. It consists of two parts: the central nervous system (CNS) comprising the brain ...

concentrate at the

anterior Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

region, forming structures responsible for information processing. Through biological evolution, sense organs and feeding structures also concentrate into the anterior region; these collectively form the head. Beethovendeathmask

Human head

The

human head In human anatomy, the head is at the top of the human body. It supports the face and is maintained by the human skull, skull, which itself encloses the human brain, brain. Structure The human head consists of a fleshy outer portion, which s ...

is an anatomical unit that consists of the skull, hyoid bone and

cervical vertebrae In tetrapods, cervical vertebrae (: vertebra) are the vertebrae of the neck, immediately below the skull. Truncal vertebrae (divided into thoracic and lumbar vertebrae in mammals) lie caudal (toward the tail) of cervical vertebrae. In saurop ...

. The skull consists of the brain case which encloses the

cranial cavity The cranial cavity, also known as intracranial space, is the space within the skull that accommodates the brain. The skull is also known as the cranium. The cranial cavity is formed by eight cranial bones known as the neurocranium that in human ...

, and the facial skeleton, which includes the

mandible In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone i ...

. There are eight bones in the brain case and fourteen in the facial skeleton. Sculptures of human heads are generally based on a skeletal structure that consists of a cranium, jawbone, and

cheekbone In the human skull, the zygomatic bone (from ), also called cheekbone or malar bone, is a paired irregular bone, situated at the upper and lateral part of the face and forming part of the lateral wall and floor of the orbit (anatomy), orbit, of t ...

. Though the number of muscles making up the face is generally consistent between sculptures, the shape of the muscles varies widely based on the function, development, and expressions reflected on the faces of the subjects. Proponents of identism believe that the mind is identical to the brain. Philosopher

John Searle John Rogers Searle (; born July 31, 1932) is an American philosopher widely noted for contributions to the philosophy of language, philosophy of mind, and social philosophy. He began teaching at UC Berkeley in 1959 and was Willis S. and Mario ...

asserts his identist beliefs, stating "the

is the only thing in the human head". Similarly, Dr. Henry Bennet-Clark has stated that the head encloses billions of "miniagents and microagents (with no single Boss)". File:View of a Skull III.jpg , Mid-sagittal section of a human skull, by

Leonardo da Vinci Leonardo di ser Piero da Vinci (15 April 1452 - 2 May 1519) was an Italian polymath of the High Renaissance who was active as a painter, draughtsman, engineer, scientist, theorist, sculptor, and architect. While his fame initially rested o ...

, File:Bartholin head transect.jpg , Transection of a human head, by Thomas Bartholin, 1673

Other animals

The evolution of a head is associated with the cephalization that occurred in

Bilateria Bilateria () is a large clade of animals characterised by bilateral symmetry during embryonic development. This means their body plans are laid around a longitudinal axis with a front (or "head") and a rear (or "tail") end, as well as a left� ...

some 555 million years ago.

Arthropods

In some

arthropod Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...

s, especially trilobites, the cephalon, or cephalic region, is the region of the head which is a collective of "fused segments".

Insects

A typical insect head is composed of eyes, antennae, and components of mouth. As these components differ substantially from insect to insect, they form important identification links. Eyes in the head found, in several types of insects, are in the form of a pair of compound eyes with multiple faces. In many other types of insects, the compound eyes are seen in a "single facet or group of single facets". In some cases, the eyes may be seen as marks on the

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...

or located near or toward the head, two or three ocelli (single faceted organs). Antennae on the insect's head is found in the form of segmented attachments, in pairs, that are usually located between the eyes. These are in varying shapes and sizes, in the form of filaments or in different enlarged or clubbed form. Insects have mouth parts in various shapes depending on their feeding habits. Labrum is the "upper lip" which is in the front area of the head and is the most exterior part. A pair of mandibles is found on the backside of the labrum flanking the side of the mouth, succeeded by a pair of maxillae each of which is known as maxilliary palp. At the back side of the mouth is the labium or lower lip. There is also an extra mouth part in some insects which is termed as hypopharynx which is usually located between the maxillac.

Vertebrates and the "new head hypothesis"

Though

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

chordates – such as the tunicate larvae or the lancelets – have heads, there has been a question of how the vertebrate head, characterized by a bony skull clearly separated from the main body, might have evolved from the head structures of these animals. According to Hyman (1979), the evolution of the head in the

vertebrates Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...

has occurred by the fusion of a fixed number of anterior segments, in the same manner as in other "heteronomously segmented animals". In some cases, segments or a portion of the segments disappear. The head segments also lose most of their systems, except for the nervous system. With the progressive development of cephalization, "the head incorporates more and more of the adjacent segments into its structure, so that in general it may be said that the higher the degree of cephalization the greater is the number of segments composing the head". In the 1980s, the "new head hypothesis" was proposed, suggesting that the vertebrate head is an evolutionary novelty resulting from the emergence of

neural crest The neural crest is a ridge-like structure that is formed transiently between the epidermal ectoderm and neural plate during vertebrate development. Neural crest cells originate from this structure through the epithelial-mesenchymal transition, ...

and cranial placodes. In 2014, a transient

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

tissue of the lancelet was found to be virtually indistinguishable from the neural crest-derived

cartilage Cartilage is a resilient and smooth type of connective tissue. Semi-transparent and non-porous, it is usually covered by a tough and fibrous membrane called perichondrium. In tetrapods, it covers and protects the ends of long bones at the joints ...

which forms the vertebrate skull, suggesting that persistence of this tissue and expansion into the entire headspace could be a viable evolutionary route to formation of the vertebrate head.

In society and culture

Heraldry

The heads of humans and other animals are commonly recurring charges in

heraldry Heraldry is a discipline relating to the design, display and study of armorial bearings (known as armory), as well as related disciplines, such as vexillology, together with the study of ceremony, Imperial, royal and noble ranks, rank and genealo ...

. Heads of humans are sometimes blazoned simply as a "man's head", but are far more frequently described in greater detail, either characteristic of a particular race or nationality (such as Moors' heads, Saxons' heads, Egyptians' heads or Turks' heads), or specifically identified (such as the head of Moses in the crest of Hilton, or the head of St. John the Baptist in the crest of the London Company of Tallowchandlers). Several varieties of women's heads also occur, including maidens' heads (often couped under the bust, with hair disheveled), ladies' heads, nuns' heads (often veiled), and occasionally queens' heads. The arms of Devaney of Norfolk include "three nun's heads veiled couped at the shoulders proper," and the bust of a queen occurs in the arms of Queenborough, Kent. Infants' or children's heads are often couped at the shoulders with a snake wrapped around the neck (e.g. "Argent, a boy's head proper, crined or, couped below the shoulders, vested gules, tarnished gold," in the arms of Boyman).

Art

One of the ways of drawing sketches of heads—as Jack Hamm advises—is to develop it in six well-defined steps, starting with the shape of the head in the shape of an egg. The female head, in particular, is sketched in a double circle design procedure with proportions considered as an ideal of a female head. In the first circle, the division is made of five sections on the

diameter In geometry, a diameter of a circle is any straight line segment that passes through the centre of the circle and whose endpoints lie on the circle. It can also be defined as the longest Chord (geometry), chord of the circle. Both definitions a ...

, each section of five eyes width. It is then developed over a series of ten defined steps, with the smaller circle imposed partially over the larger circle at the lower end at the fourth stage. Eyes and chins are fitted in various shapes to form the head.

, considered one of the world's greatest artists, drew sketches of human anatomy using grid structures. His image of the face drawn on the grid structure principle is in perfect proportion. In this genre, using the technique of pen and ink, Leonardo created a sketch which is a "Study on the proportions of head and eyes" (pictured).

Idiomatic expressions

idiom An idiom is a phrase or expression that largely or exclusively carries a Literal and figurative language, figurative or non-literal meaning (linguistic), meaning, rather than making any literal sense. Categorized as formulaic speech, formulaic ...

is a phrase or a fixed expression that has a figurative, or sometimes literal, meaning. * "To be big-headed" - to be overly full of oneself * "To come to a head" – to reach a critical stage and require immediate action * "To bite someone's head off" – to criticize someone strongly * " Can't make head or tail of something" – cannot understand something * "A head start" – an early start that provides an advantage over others * " Head and shoulders above someone or something" – better than someone or something in some way * "To want someone's head on a platter" – to want someone severely punished * "To bang your head against a brick wall" – to continually try to achieve something without success * "To have one's head in the clouds" – to not pay attention to what is happening around one because one is so absorbed by one's own thoughts

Engineering and scientific fields

The head's function and appearance play an analogous role in the etymology of many technical terms. Cylinder head, pothead, and weatherhead are three such examples.

Gallery

File:Head nerves.gif, Nerves of the human head, from '' Gray's Anatomy'', 1858 File:Andrea Vaccaro, Tête de Saint-Jean Baptiste.jpg, Head of St. John the Baptist by Andrea Vaccaro, oil on canvas, 17th century File:Statue de Saint Solange.JPG, Sculpture of the beheaded Saint Solange, patron saint of the French province of Berry File:Zürcher Stadtheilige.jpg, Patron saints of

Zürich Zurich (; ) is the list of cities in Switzerland, largest city in Switzerland and the capital of the canton of Zurich. It is in north-central Switzerland, at the northwestern tip of Lake Zurich. , the municipality had 448,664 inhabitants. The ...

, fresco, File:POL powiat kaliski COA (1999-2024).svg, Heraldic depiction of a

bison A bison (: bison) is a large bovine in the genus ''Bison'' (from Greek, meaning 'wild ox') within the tribe Bovini. Two extant taxon, extant and numerous extinction, extinct species are recognised. Of the two surviving species, the American ...

head cabossed