Editing Head

{{short description|Cephalic part of an animal}}
{{About|heads in general|the heads of humans|Human head|other uses}}
{{pp-move}}
{{Use dmy dates|date=September 2015}}
{{Infobox anatomy
| Name            = Head
| Latin           = caput
| Image          = Portrait of a Meerkat.jpg
| Caption         = The head of a [[meerkat]]
}}

A '''head''' is the part of an [[organism]] which usually includes the [[ear]]s, [[brain]], [[forehead]], [[cheek]]s, [[chin]], [[eye]]s, [[nose]], and [[mouth]], each of which aid in various sensory functions such as [[visual perception|sight]], [[hearing]], [[olfaction|smell]], and [[taste]]. Some very simple animals may not have a head, but many [[bilateria|bilaterally symmetric forms]] do, regardless of size. 

Heads develop in animals by an [[evolution]]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.
[[File:Beethovendeathmask.jpg|thumb|The head of a [[death mask]]]]

== Human head ==

{{main|Human head|Head and neck anatomy}}

The [[human head]] is an anatomical unit that consists of the [[Human skull |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.<ref name="Halim2008">{{cite book |first=A. |last=Halim |title=Human Anatomy:Volume Iii: Head, Neck And Brain |url=https://books.google.com/books?id=nx0a1AIiBKQC | date=30 December 2008 |publisher=I. K. International |isbn=978-81-906566-4-1 |page=3}}</ref>

Sculptures of human heads are generally based on a [[Human skeleton |skeletal]] structure that consists of a cranium, [[jaw]]bone, 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.<ref name="Slobodkin1973">{{cite book |first=Louis |last=Slobodkin |title=Sculpture: Principles and Practice |url=https://books.google.com/books?id=ugsSRVCgkicC&pg=PA31 |year=1973 |publisher=Courier Corporation |isbn=978-0-486-22960-7 |page=31}}</ref>

Proponents of [[wikt:identism |identism]] believe that the mind is identical to the brain. Philosopher [[John Searle]] asserts his identist beliefs, stating "the [[Human brain |brain]] 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)".<ref name="Cobb2008">{{cite book |first=John B. |last=Cobb |title=Back To Darwin: A Richer Account of Evolution |url=https://books.google.com/books?id=cuhxgMlqjbwC&pg=PA375 |date=4 February 2008 |publisher=Wm. B. Eerdmans Publishing |isbn=978-0-8028-4837-6 |pages=371–375}}</ref>

<gallery>
File:View of a Skull III.jpg |[[Sagittal plane |Mid-sagittal]] section of a [[human skull]], by [[Leonardo da Vinci]], {{Circa |1489}}
File:Bartholin head transect.jpg |Transection of a human head, by [[Thomas Bartholin]], 1673
</gallery>

== Other animals ==
The evolution of a head is associated with the [[cephalization]] that occurred in [[Bilateria]] some 555 million years ago.

=== Arthropods ===
{{Main article|Cephalon (arthropod head)}}
In some [[arthropod]]s, especially [[trilobite]]s, the [[Cephalon (arthropod head)|cephalon]], or cephalic region, is the region of the head which is a collective of "fused segments".<ref name="Stevenson2010">{{cite book|first=Angus|last=Stevenson|title=Oxford Dictionary of English|url=https://books.google.com/books?id=anecAQAAQBAJ&pg=PA283|date=19 August 2010|publisher=OUP Oxford|isbn=978-0-19-957112-3|pages=283–}}</ref>

==== Insects ====
[[File:Nomada krugii, F, face, Dominican Republic, La Ve jarabacoa 2012-12-05-14.31.04 ZS PMax (8258588812).jpg|thumbnail|Head of a [[Nomada]]-species [[bee]]]]

A typical insect head is composed of eyes, [[antenna (biology)|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 eye|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 [[dorsum (anatomy)|dorsal]] or located near or toward the head, two or three [[ocelli]] (single faceted organs).<ref name="McCafferty1983">{{cite book|first=W. Patrick|last=McCafferty|title=Aquatic Entomology: The Fishermen's and Ecologists' Illustrated Guide to Insects and Their Relatives|url=https://books.google.com/books?id=wiTq7x-fI_0C&pg=PA20|date=1 January 1983|publisher=Jones & Bartlett Learning|isbn=978-0-86720-017-1|pages=20–}}</ref>

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.<ref name="McCafferty1983"/>

Insects have mouth parts in various shapes depending on their feeding habits. [[Labrum (arthropod mouthpart)|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 [[Maxilla (arthropod mouthpart)|maxillae]] each of which is known as [[maxilliary palp]]. At the back side of the mouth is the [[labium (arthropod mouthpart)|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]].<ref name="McCafferty1983"/>

{{anchor|Vertebrate}}
{{anchor|New head hypothesis}}

=== Vertebrates and the "new head hypothesis" ===
Though [[invertebrate]] [[chordate]]s – such as the [[tunicate]] larvae or the [[lancelet]]s – 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.<ref name="jandzik2014" />

According to Hyman (1979), the evolution of the head in the [[vertebrates]] 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".<ref name="Hyman1992">{{cite book|first=Libbie Henrietta|last=Hyman|title=Hyman's Comparative Vertebrate Anatomy|url=https://books.google.com/books?id=VKlWjdOkiMwC&pg=PA4|date=1979|publisher=University of Chicago Press|isbn=978-0-226-87013-7 |edition=3rd |pages=4. [1st ed., 1922; 2nd ed., 1942.; 3rd ed., 1979, reprinted in 1992.]}}</ref>

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 [[placode]]s.<ref>{{Cite journal |last1=Gans |first1=Carl |last2=Northcutt |first2=R. Glenn |date=1983-04-15 |title=Neural Crest and the Origin of Vertebrates: A New Head |url=https://www.science.org/doi/10.1126/science.220.4594.268 |journal=Science |language=en |volume=220 |issue=4594 |pages=268–273 |doi=10.1126/science.220.4594.268 |pmid=17732898 |bibcode=1983Sci...220..268G |s2cid=39290007 |issn=0036-8075|url-access=subscription }}</ref><ref>{{Cite journal |last1=Diogo |first1=Rui |last2=Kelly |first2=Robert G. |last3=Christiaen |first3=Lionel |last4=Levine |first4=Michael |last5=Ziermann |first5=Janine M. |last6=Molnar |first6=Julia L. |last7=Noden |first7=Drew M. |last8=Tzahor |first8=Eldad |date=2015-04-23 |title=A new heart for a new head in vertebrate cardiopharyngeal evolution |journal=Nature |language=en |volume=520 |issue=7548 |pages=466–473 |doi=10.1038/nature14435 |issn=0028-0836 |pmc=4851342 |pmid=25903628|bibcode=2015Natur.520..466D }}</ref> 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.<ref name="jandzik2014" />

== In society and culture ==

=== Heraldry ===
[[File:Flag of Corsica.svg|thumb|The [[flag]] of [[Corsica]] displays a head in profile view]]
{{Main article|Heads in heraldry}}

The heads of humans and other animals are commonly recurring [[charge (heraldry)|charges]] in [[heraldry]].<ref name=Herald>{{Cite web|url=http://www.heraldsnet.org/saitou/parker/Jpglossh.htm|title=H|work=Head|publisher= heraldsnet.org}}</ref> 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).<ref name=Herald/><ref name="Fox-Davies2007">{{cite book|first=Arthur Charles|last=Fox-Davies|title=A Complete Guide to Heraldry|url=https://books.google.com/books?id=xSeEWjQCTIAC|year=2007|publisher=Skyhorse Publishing Inc.|isbn=978-1-60239-001-0}}</ref> 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|Queenborough, Kent]].<ref name=Herald/> 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).<ref name=Herald/>
<!--<gallery class="center" caption="" widths="160px" heights="210px">
File:Flag of Corsica.svg|The [[flag]] of [[Corsica]] displays a head in profile view
</gallery> -->
=== Art ===
{{multiple image
| align = right
| image1 = Leonardo da vinci, Study on the proportions of head and eyes.jpg
| caption1 = Study on the proportions of head and eyes by [[Leonardo da Vinci]]
| width1 = 200
| image2 = Domenico Beccafumi - Tête de jeune homme.jpg
| caption2 = "''Head of a young man''"&nbsp;– [[Domenico Beccafumi]]
| width2 = 192
|}}
One of the ways of drawing [[Sketch (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]], 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.<ref>{{cite book|title=Drawing the Head and Figure|url=https://books.google.com/books?id=qI91-vhOm8wC|date=January 1983|publisher=Penguin|isbn=978-0-399-50791-5}}</ref>

[[Leonardo da Vinci]], 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.<ref>{{Cite web|url=http://www.royalcollection.org.uk/sites/default/files/Learning_davinci.swf|title=Leonardo da Vinci Face facts|publisher=royalcollection.org|access-date=17 September 2015|archive-date=4 March 2016|archive-url=https://web.archive.org/web/20160304061724/http://www.royalcollection.org.uk/sites/default/files/Learning_davinci.swf|url-status=dead}}</ref> 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]] is a phrase or a fixed expression that has a figurative, or sometimes literal, meaning.
* "To be [[wiktionary:big-headed|big-headed]]"&nbsp;- to be overly full of oneself
* "To [[wiktionary:come_to_a_head|come to a head]]"&nbsp;– to reach a critical stage and require immediate action<ref name="Dolgopolov 2004 p. 104"/>
* "To [[wiktionary:bite_someone's_head_off|bite someone's head off]]"&nbsp;– to criticize someone strongly<ref name="Palmatier 2000 p. 24"/>
* "[[wiktionary:make_head_or_tail_of|Can't make head or tail of something]]"&nbsp;– cannot understand something<ref name="Curtis 2015 p. 84"/>
* "A [[wiktionary:head_start|head start]]"&nbsp;– an early start that provides an advantage over others<ref name="Ammer 2013 p. 206"/>
* "[[wiktionary:head_and_shoulders|Head and shoulders]] above someone or something"&nbsp;–  better than someone or something in some way<ref name="Brenner 2011 p. 234"/>
* "To want someone's [[wiktionary:hand_someone_his_head_on_a_platter|head on a platter]]"&nbsp;– to want someone severely punished<ref>{{cite dictionary|title=head on a platter|url=http://idioms.thefreedictionary.com/head+on+a+platter|via=[[TheFreeDictionary.com]]|dictionary=Cambridge Idioms Dictionary|edition=2nd|access-date=17 September 2015|year=2006}}</ref>
* "To [[wiktionary:bang_one's_head_against_a_brick_wall|bang your head against a brick wall]]"&nbsp;– to continually try to achieve something without success<ref name="Ayto 2010 p. 45"/>
* "To have one's [[wiktionary:head_in_the_clouds|head in the clouds]]"&nbsp;– to not pay attention to what is happening around one because one is so absorbed by one's own thoughts<ref name="Kirkpatrick Schwarz 1993"/><ref>{{cite web |url=http://www.learn-english-today.com/idioms/idiom-categories/body/head.html |title= English Idioms & Idiomatic Expressions – Body idioms/Head|author=<!--Staff writer(s); no by-line.--> |year=2015 |website= Learn English Today |access-date= 14 September 2015}}</ref>

===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 ==
<gallery mode="packed">
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 [[John the Baptist|St. John the Baptist]] by [[Andrea Vaccaro]], oil on canvas, 17th century
File:Statue de Saint Solange.JPG|Sculpture of the beheaded [[Solange (saint)|Saint Solange]], patron saint of the French [[Berry (province)|province of Berry]]
File:Zürcher Stadtheilige.jpg|Patron saints of [[Zürich]], fresco, {{Circa|1400–1425}}
File:POL powiat kaliski COA (1999-2024).svg|Heraldic depiction of a [[bison]] head [[cabossed]]
</gallery>

== See also ==
* [[Cephalic disorder]]
* [[Cephalic flexure]]
* [[Cephalic index]]
* [[Cephalic phase]]
* [[Cephalic presentation]]
* [[Cephalic vein]]
* ''[[Circle of Animals/Zodiac Heads]]''&nbsp;– an artwork by Chinese contemporary artist and political commentator Ai Weiwei
* [[Cynocephaly]]&nbsp;– a characteristic of having the head of a dog or of a jackal. It is a widely attested [[Mythology|mythical]] phenomenon existing in many forms and contexts.
* [[Khutang]]&nbsp;– a type of [[harp]] often surmounted by a carven animal head, often a swan
* [[Theriocephaly]]&nbsp;– in some [[religious belief]]s, the condition or quality of having the head of an animal, commonly used to refer the depiction in art of humans (or [[Deity|deities]]) with animal heads

== References ==
{{reflist|30em|refs=
<ref name="jandzik2014">{{cite journal | doi = 10.1038/nature14000| title = Evolution of the new vertebrate head by co-option of an ancient chordate skeletal tissue| journal = Nature| year = 2014| last1 = Jandzik | first1 = D. | last2 = Garnett | first2 = A. T. | last3 = Square | first3 = T. A. | last4 = Cattell | first4 = M. V. | last5 = Yu | first5 = J. K. | last6 = Medeiros | first6 = D. M. | volume=518 | issue = 7540| pages=534–537 | pmid=25487155| s2cid = 4449267}}  ''For lay summary see:'' {{cite journal | journal=[[Nature (journal)|Nature]] | department=Research | page=171 | type=paper | date=11 December 2014 | title=Evolution: How vertebrates got a head | volume=516 | issue=7530 }}</ref>
<ref name="Dolgopolov 2004 p. 104">{{cite book | last=Dolgopolov | first=Y. | title=A Collection of Confusible Phrases | publisher=Llumina Press | year=2004 | isbn=978-1-59526-334-6 | url=https://books.google.com/books?id=wuLrTJ0wtlMC&pg=PA104 | page=104}}</ref>
<ref name="Palmatier 2000 p. 24">{{cite book | last=Palmatier | first=R.A. | title=Food: A Dictionary of Literal and Nonliteral Terms | publisher=Greenwood Press | series=ABC-Clio ebook | year=2000 | isbn=978-0-313-31436-0 | url=https://archive.org/details/fooddictionaryof00palm | url-access=registration | page=[https://archive.org/details/fooddictionaryof00palm/page/24 24]}}</ref>
<ref name="Curtis 2015 p. 84">{{cite book | last=Curtis | first=S. | title=Connect: Stories Behind Idioms 1: Making sense of their origins and meanings | publisher=Acel Learning (S) Pte Limited | series=Connect | year=2015 | isbn=978-981-09-5822-0 | url=https://books.google.com/books?id=LU0WCgAAQBAJ&pg=PA84 | page=84}}</ref>
<ref name="Ammer 2013 p. 206">{{cite book | last=Ammer | first=C. | title=The American Heritage Dictionary of Idioms, Second Edition | publisher=Houghton Mifflin Harcourt | year=2013 | isbn=978-0-547-67753-8 | url=https://books.google.com/books?id=9QuEiIMaBt0C&pg=PA206 | page=206}}</ref>
<ref name="Brenner 2011 p. 234">{{cite book | last=Brenner | first=G. | title=Webster's New World American Idioms Handbook | publisher=Houghton Mifflin Harcourt | year=2011 | isbn=978-0-544-18890-7 | url=https://books.google.com/books?id=m7le7O8KAEwC&pg=PT234 | page=PT 234}}</ref>
<ref name="Ayto 2010 p. 45">{{cite book | last=Ayto | first=J. | title=Oxford Dictionary of English Idioms | publisher=OUP Oxford | series=Oxford Paperback Reference | year=2010 | isbn=978-0-19-954378-6 | url=https://books.google.com/books?id=g9ynBrageYIC&pg=PA45 | page=45}}</ref>
<ref name="Kirkpatrick Schwarz 1993">{{cite book | last1=Kirkpatrick | first1=E.M.L. | last2=Schwarz | first2=C.M. | title=The Wordsworth Dictionary of Idioms | publisher=Wordsworth | series=Reference Library | year=1993 | isbn=978-1-85326-309-5 | url=https://books.google.com/books?id=8C7k7ZW3dIEC&pg=PA156 |page=156}}</ref>
}}

== Further reading ==
{{Commons category|Heads}}
{{Wiktionary|head|cephalic}}
{{Wikiquote}}
*{{cite book|last=Lieberman|first=Daniel E. |title=Evolution of the Human Head|url=https://books.google.com/books?id=KvIDVlSExS8C&pg=PA207|date=3 May 2011|publisher=Harvard University Press|isbn=978-0-674-05944-3}}

{{Authority control}}

[[Category:Head| ]]