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,
cheeks,
chin,
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,
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 concentrate at the
anterior 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.
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. The skull consists of the brain case which encloses the
cranial cavity, and the
facial skeleton, which includes the
mandible. 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. 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 asserts his identist beliefs, stating "the
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 ...
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 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 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 and cranial
placodes. In 2014, a transient
larva tissue of the lancelet was found to be virtually indistinguishable from the neural crest-derived
cartilage 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.
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.
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 ...
, 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
An 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
See also
* Cephalic disorder
* Cephalic flexure
* Cephalic index
The cephalic index or cranial index is a number obtained by taking the maximum width (biparietal diameter or BPD, side to side) of the head of an organism, multiplying it by 100 and then dividing it by their maximum length (occipitofrontal diame ...
* Cephalic phase
* Cephalic presentation
* Cephalic vein
* '' Circle of Animals/Zodiac Heads'' – an artwork by Chinese contemporary artist and political commentator Ai Weiwei
* Cynocephaly – a characteristic of having the head of a dog or of a jackal. It is a widely attested mythical phenomenon existing in many forms and contexts.
* Khutang – a type of harp often surmounted by a carven animal head, often a swan
* Theriocephaly – in some religious beliefs, the condition or quality of having the head of an animal, commonly used to refer the depiction in art of humans (or deities
A deity or god is a supernatural being considered to be sacred and worthy of worship due to having authority over some aspect of the universe and/or life. The ''Oxford Dictionary of English'' defines ''deity'' as a God (male deity), god or god ...
) with animal heads
References
Further reading
*
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