document_title: The Silence of the Lambs (film)

question_text: who plays hannibal in silence of the lambs

root

text: The Silence of the Lambs (film)

text: Plot

text: FBI trainee and UVA graduate, Clarice Starling, is pulled from her training at the FBI Academy at Quantico, Virginia by Jack Crawford of the Bureau's Behavioral Science Unit. He assigns her to interview Hannibal Lecter, a former psychiatrist and incarcerated cannibalistic serial killer, whose insight might prove useful in the pursuit of a serial killer nicknamed "Buffalo Bill", who skins his female victims' corpses.

tag: p

text: Starling travels to the Baltimore State Hospital for the Criminally Insane, where she is led by Dr. Frederick Chilton to Lecter's solitary quarters. Although initially pleasant and courteous, Lecter grows impatient with Starling's attempts at "dissecting" him and rebuffs her. As she is leaving, one of the prisoners flicks semen at her. Lecter, who considers this act "unspeakably ugly", calls Starling back and tells her to seek out an old patient of his. This leads her to a storage shed, where she discovers a man's severed head with a sphinx moth lodged in its throat. She returns to Lecter, who tells her that the man is linked to Buffalo Bill. He offers to profile Buffalo Bill on the condition that he may be transferred away from Chilton, whom he detests.

text: Buffalo Bill abducts a Senator's daughter, Catherine Martin. Crawford authorizes Starling to offer Lecter a fake deal, promising a prison transfer if he provides information that helps them find Buffalo Bill and rescue Catherine. Instead, Lecter demands a quid pro quo from Starling, offering clues about Buffalo Bill in exchange for personal information. Starling tells Lecter about the murder of her father when she was ten years old. Chilton secretly records the conversation and reveals Starling's deceit before offering Lecter a deal of Chilton's own making. Lecter agrees and is flown to Memphis, Tennessee, where he verbally torments Senator Ruth Martin, and gives her misleading information on Buffalo Bill, including the name "Louis Friend".

text: Starling notices that "Louis Friend" is an anagram of "iron sulfide" — fool's gold. She visits Lecter, who is now being held in a cage-like cell in a Tennessee courthouse, and asks for the truth. Lecter tells her that all the information she needs is contained in the case file. Rather than give her the real name, he insists that they continue their quid pro quo and she recounts a traumatic childhood incident where she was awakened by the sound of spring lambs being slaughtered on a relative's farm in Montana. Starling admits that she still sometimes wakes thinking she can hear lambs screaming, and Lecter speculates that she is motivated to save Catherine in the hope that it will end the nightmares. Lecter gives her back the case files on Buffalo Bill after their conversation is interrupted by Chilton and the police, who escort her from the building. Later that evening, Lecter kills his guards, escapes from his cell, and disappears.

text: Starling analyzes Lecter's annotations to the case files and realizes that Buffalo Bill knew his first victim personally. Starling travels to the victim's hometown and discovers that Buffalo Bill was a tailor, with dresses and dress patterns identical to the patches of skin removed from each of his victims. She telephones Crawford to inform him that Buffalo Bill is trying to form a "woman suit" out of real skin, but Crawford is already en route to make an arrest, having cross-referenced Lecter's notes with hospital archives and finding a transsexual man named Jame Gumb, who once applied unsuccessfully for a sex-change operation. Starling continues interviewing friends of Buffalo Bill's first victim in Ohio, while Crawford leads an FBI HRT team to Gumb's address in Illinois. The house in Illinois is empty, and Starling is led to the house of "Jack Gordon", whom she realizes is actually Jame Gumb, again by finding a sphinx moth. She pursues him into his multi-room basement, where she discovers that Catherine is still alive, but trapped in a dry well. After turning off the basement lights, Gumb stalks Starling in the dark with night-vision goggles, but gives his position away when he cocks his revolver. Starling reacts just in time and fires all of her rounds at Gumb, killing him.

text: Sometime later, at the FBI Academy graduation party, Starling receives a phone call from Lecter, who is at an airport in Bimini. He assures her that he does not plan to pursue her and asks her to return the favor, which she says she cannot do. Lecter then hangs up the phone, saying that he is "having an old friend for dinner", and starts following a newly arrived Chilton before disappearing into the crowd.

text: Cast

text:
Jodie Foster as Clarice Starling

Masha Skorobogatov as young Clarice

Anthony Hopkins as Dr. Hannibal Lecter
Scott Glenn as Jack Crawford
Ted Levine as Jame "Buffalo Bill" Gumb
Anthony Heald as Dr. Frederick Chilton
Brooke Smith as Catherine Martin
Diane Baker as U.S. Senator Ruth Martin
Kasi Lemmons as Ardelia Mapp
Frankie Faison as Barney Matthews
Tracey Walter as Lamar
Charles Napier as Lt. Boyle
Danny Darst as Sgt. Tate
Alex Coleman as Sgt. Jim Pembry
Dan Butler as Roden
Paul Lazar as Pilcher
Ron Vawter as Paul Krendler
Roger Corman as FBI Director Hayden Burke
Chris Isaak as SWAT Commander
Harry Northup as Mr. Bimmel

tag: ul

text: Production

text: Development

text: The Silence of the Lambs is based on Thomas Harris' 1988 novel of the same name and is the second film to feature the character Hannibal Lecter following the 1986 film Manhunter. Prior to the novel's release, Orion Pictures partnered with Gene Hackman to bring the novel to the big screen. With Hackman set to direct and possibly star in the role of Crawford, negotiations were made to split the $500,000 cost of rights between Hackman and the studio.[6] In addition to securing the rights to the novel, producers also had to acquire the rights to the name "Hannibal Lecter", which were owned by Manhunter producer Dino De Laurentiis. Owing to the financial failure of the earlier film, De Laurentiis lent the character rights to Orion Pictures for free.[7]

text: In November 1987, Ted Tally was brought on to write the adaptation;[8] Tally had previously crossed paths with Harris many times, with his interest in adapting The Silence of the Lambs originating from receiving an advance copy of the book from Harris himself.[9] When Tally was about halfway through with the first draft, Hackman withdrew from the project and financing fell through. However, Orion Pictures co-founder Mike Medavoy assured Tally to keep writing as the studio itself took care of financing and searched for a replacement director.[10] As a result, Orion Pictures sought director Jonathan Demme to helm the project. With the screenplay not yet completed, Demme signed on after reading the novel.[11] From there, the project quickly took off, as Tally explained, "[Demme] read my first draft not long after it was finished, and we met, then I was just startled by the speed of things. We met in May 1989 and were shooting in November. I don't remember any big revisions."[12]

text: Casting

text: Jodie Foster was interested in playing the role of Clarice Starling immediately after reading the novel. However, despite Foster's having just won an Academy Award for her performance in the 1988 film The Accused, Demme was not convinced that she was right for the part.[13][14] Having previously collaborated on Married to the Mob, Demme's first choice for the role of Starling was Michelle Pfeiffer, who turned it down, later saying, "It was a difficult decision, but I got nervous about the subject matter".[15] As a result, Foster was awarded the role due to her passion towards the character.[16]

text: For the role of Dr. Hannibal Lecter, Demme originally approached Sean Connery. After the actor turned it down, Anthony Hopkins was then offered the part based on his performance in The Elephant Man.[17] Other actors considered for the role included Al Pacino,[18] Robert De Niro,[18] Dustin Hoffman,[18] Derek Jacobi[19] and Daniel Day-Lewis.[19]

text: Gene Hackman was originally going to play Jack Crawford, the Agent-in-Charge of the Behavioral Science Unit of the FBI in Quantico, Virginia but he found the script "too violent."[18] Scott Glenn was then cast in the role. To prepare for the role, Glenn met with John E. Douglas, after whom the character is modeled. Douglas gave Glenn a tour of the Quantico facility and also played for him an audio tape containing various recordings that serial killers Lawrence Bittaker and Roy Norris had made of themselves raping and torturing a 16-year-old girl.[20][21] According to Douglas, Glenn wept as he experienced the recordings and even changed his liberal stance on the death penalty.[22]

text: Filming

text: Principal photography for The Silence of the Lambs began on November 15, 1989 and concluded on March 1, 1990.[23] Filming primarily took place in and around Pittsburgh, Pennsylvania, with some scenes shot in nearby northern West Virginia.[24] The home of Buffalo Bill used for exterior scenes was in Layton, Pennsylvania.[25][26] The exterior of the Western Center near Canonsburg, Pennsylvania served as the setting for Baltimore State Hospital for the Criminally Insane.[27] In what was a rare act of cooperation at the time, the FBI allowed scenes to be filmed at the FBI Academy in Quantico; some FBI staff members even acted in bit parts.[28][29]

text: Music

text:
The Silence of the Lambs: The Original Motion Picture Score

Film score by Howard Shore

Released
February 5, 1991

Recorded
August, 1990 in Munich

Length
57:09

Label
MCA Records

Producer
Howard Shore

Howard Shore chronology

Big
(1988)Big1988
The Silence of the Lambs
(1991)
Naked Lunch
(1991)Naked Lunch1991

Hannibal Lecter chronology

Manhunter
(1986) Manhunter1986
The Silence of the Lambs
(1991) The Silence of the Lambs1991
Hannibal
(2001) Hannibal2001

tag: table

text:
Professional ratings

Review scores

Source
Rating

Allmusic

Filmtracks.com

text: The musical score for The Silence of the Lambs was composed by Howard Shore, who would also go on to collaborate with Demme on Philadelphia. Recorded in Munich during the latter half of the summer of 1990, the score was performed by the Munich Symphony Orchestra.[30] "I tried to write in a way that goes right into the fabric of the movie," explained Shore on his approach. "I tried to make the music just fit in. When you watch the movie you are not aware of the music. You get your feelings from all elements simultaneously, lighting, cinematography, costumes, acting, music. Jonathan Demme was very specific about the music."[31] A soundtrack album was released by MCA Records on February 5, 1991.[32] Music from the film was later used in the trailers for its sequel, Hannibal.[33]

text:
The Silence of the Lambs: The Original Motion Picture Score

No.
Title
Length

1.
"Main Title"
5:04

2.
"The Asylum"
3:53

3.
"Clarice"
3:03

4.
"Return to the Asylum"
2:35

5.
"The Abduction"
3:01

6.
"Quid Pro Quo"
4:41

7.
"Lecter in Memphis"
5:41

8.
"Lambs Screaming"
5:34

9.
"Lecter Escapes"
5:06

10.
"Belvedere, Ohio"
3:32

11.
"The Moth"
2:20

12.
"The Cellar"
7:02

13.
"Finale"
4:50

Total length:
57:09

text: Release

text: The Silence of the Lambs was released on February 14, 1991, grossing $14 million during its opening weekend. At the time it closed on October 10, 1991, the film had grossed $131 million domestically with a total worldwide gross of $273 million.[34] It was the fourth highest-grossing film of 1991.[35]

text: Critical reception

text: The Silence of the Lambs was a sleeper hit that gradually gained widespread success and critical acclaim.[36] Hopkins, Foster, and Levine garnered much acclaim for their performances. Review aggregator Rotten Tomatoes reports that 95% of 84 film critics have given the film a positive review, with an average rating of 8.7 out of 10. The website's critical consensus reads: "Director Jonathan Demme's smart, taut thriller teeters on the edge between psychological study and all-out horror, and benefits greatly from stellar performances by Anthony Hopkins and Jodie Foster."[37] Metacritic, another review aggregator, assigned the film a weighted average score of 85 out of 100, based on 19 reviews from mainstream critics, indicating "universal acclaim".[38] Audiences polled by CinemaScore gave the film an average grade of "A-" on an A+ to F scale.[39]

text: Roger Ebert, of Chicago Sun-Times, specifically mentioned the "terrifying qualities" of Hannibal Lecter.[40] Ebert later added the film to his list of The Great Movies, recognizing the film as a "horror masterpiece" alongside such classics as Nosferatu, Psycho, and Halloween.[41] However, the film is also notable for being one of two multi-Academy Award winners (the other being Unforgiven) disapproved of by Ebert's colleague, Gene Siskel. Writing for Chicago Tribune, Siskel said, "Foster's character, who is appealing, is dwarfed by the monsters she is after. I'd rather see her work on another case."[42]

text: Accolades

text:
Academy Awards record

Best Picture, Edward Saxon, Kenneth Utt, Ronald M. Bozman

Best Director, Jonathan Demme

Best Actor, Anthony Hopkins

Best Actress, Jodie Foster

Best Adapted Screenplay, Ted Tally

Golden Globe Awards record

Best Actress, Jodie Foster

British Academy Film Awards record

Best Actor, Anthony Hopkins

Best Actress, Jodie Foster

text: The film won the Big Five Academy Awards: Best Picture, Best Director (Demme), Best Actor (Hopkins), Best Actress (Foster), and Best Adapted Screenplay (Ted Tally), making it only the third film in history to accomplish that feat.[43] It was also nominated for Best Sound Mixing (Tom Fleischman and Christopher Newman) and Best Film Editing, but lost to Terminator 2: Judgment Day and JFK, respectively.[44]

text: Other awards include being named Best Film by the National Board of Review of Motion Pictures, CHI Awards and PEO Awards. Demme won the Silver Bear for Best Director at the 41st Berlin International Film Festival[45] and was nominated for the Golden Globe Award for Best Director. The film was nominated for the Grand Prix of the Belgian Film Critics Association. It was also nominated for the British Academy Film Award for Best Film. Screenwriter Ted Tally received an Edgar Award for Best Motion Picture Screenplay. The film was awarded Best Horror Film of the Year during the 2nd Horror Hall of Fame telecast, with Vincent Price presenting the award to the film's executive producer Gary Goetzman.[46]

text: In 1998, the film was listed as one of the 100 greatest films in the past 100 years by the American Film Institute.[47] In 2006, at the Key Art Awards, the original poster for The Silence of the Lambs was named best film poster "of the past 35 years".[48] The Silence of the Lambs placed seventh on Bravo's The 100 Scariest Movie Moments for Lecter's escape scene. The American Film Institute named Hannibal Lecter (as portrayed by Hopkins) the number one film villain of all time[49] and Clarice Starling (as portrayed by Foster) the sixth-greatest film hero of all time.[49] In 2011, ABC aired a prime-time special, Best in Film: The Greatest Movies of Our Time, that counted down the best films chosen by fans based on results of a poll conducted by ABC and People magazine. The Silence of the Lambs was selected as the No. 1 Best Suspense/Thriller and Dr. Hannibal Lecter was selected as the No. 4 Greatest Film Character.

text: The film and its characters have appeared in the following AFI "100 Years" lists:

text:
AFI's 100 Years...100 Movies—#65
AFI's 100 Years...100 Thrills—#5
AFI's 100 Years...100 Heroes and Villains:

Hannibal Lecter—#1 Villain
Clarice Starling—#6 Hero
"Buffalo Bill" (Jame Gumb)—Nominated Villain

AFI's 100 Years...100 Movie Quotes:

"A census taker once tried to test me. I ate his liver with some fava beans and a nice Chianti."—#21
"I do wish we could chat longer, but I'm having an old friend for dinner."—Nominated

AFI's 100 Years of Film Scores—Nominated
AFI's 100 Years...100 Movies (10th Anniversary Edition)—#74

text: In 2015, Entertainment Weekly's 25th anniversary year, it included The Silence of the Lambs in its list of the 25 best movies made since the magazine's beginning.[50]

text:
Organization/Association
Award
Actor/Crew
Outcome
Remarks

64th Academy Awards
Best Actor
Anthony Hopkins
Won

Best Actress
Jodie Foster
Won

Best Adapted Screenplay
Ted Tally
Won
Adapted from The Silence of the Lambs by Thomas Harris

Best Director
Jonathan Demme
Won

Best Picture
Edward Saxon, Kenneth Utt, Ron Bozman
Won

Best Film Editing
Craig McKay
Nominated

Best Sound Mixing
Tom Fleischman, Christopher Newman
Nominated

49th Golden Globe Awards
Best Actress in a Motion Picture – Drama
Jodie Foster
Won

Best Actor – Motion Picture Drama
Anthony Hopkins
Nominated

Best Director
Jonathan Demme
Nominated

Best Motion Picture – Drama
Kenneth Utt
Nominated

Best Screenplay
Ted Tally
Nominated

45th British Academy Film Awards
Best Actor in a Leading Role
Anthony Hopkins
Won

Best Actress in a Leading Role
Jodie Foster
Won

Best Adapted Screenplay
Ted Tally
Nominated

Best Cinematography
Tak Fujimoto
Nominated

Best Direction
Jonathan Demme
Nominated

Best Editing
Craig McKay
Nominated

Best Film
Ron Bozman, Edward Saxon, Kenneth Utt
Nominated

Best Film Music
Howard Shore
Nominated

Best Sound
Skip Lievsay, Christopher Newman, Tom Fleischman
Nominated

text: Accusations of homophobia, transphobia and sexism

text: Upon its release, The Silence of the Lambs was criticized by members of the LGBT community for its portrayal of Buffalo Bill as bisexual and transsexual. In response to the critiques, Demme replied that Buffalo Bill "wasn't a gay character. He was a tormented man who hated himself and wished he was a woman because that would have made him as far away from himself as he possibly could be." Demme added that he "came to realize that there is a tremendous absence of positive gay characters in movies".[51]

text: In a 1992 interview with Playboy magazine, notable feminist and women's rights advocate Betty Friedan stated, "I thought it was absolutely outrageous that The Silence of the Lambs won four  [sic] Oscars. […] I'm not saying that the movie shouldn't have been shown. I'm not denying the movie was an artistic triumph, but it was about the evisceration, the skinning alive of women. That is what I find offensive. Not the Playboy centerfold."[52]


document_title: Cradle of civilization

question_text: where is the oldest civilization known to man

text: Cradle of civilization

text: History of the idea[edit]

text: The concept "cradle of civilization" is the subject of much debate. The figurative use of cradle to mean "the place or region in which anything is nurtured or sheltered in its earlier stage" is traced by the Oxford English Dictionary to Spenser (1590). Charles Rollin's Ancient History (1734) has "Egypt that served at first as the cradle of the holy nation".

text: The phrase "cradle of civilization" plays a certain role in national mysticism. It has been used in Eastern as well as Western cultures, for instance, in Hindu nationalism (In Search of the Cradle of Civilization 1995) and Taiwanese nationalism (Taiwan — The Cradle of Civilization[9] 2002). The terms also appear in esoteric pseudohistory, such as the Urantia Book, claiming the title for "the second Eden", or the pseudoarchaeology related to Megalithic Britain (Civilization One 2004, Ancient Britain: The Cradle of Civilization 1921).

text: Rise of civilization[edit]

text:
Ancient history

Preceded by Prehistory

Ancient Near East

Sumer
Egypt
Assyria
Elam
Akkad
Babylonia
Canaan
Israel and Judah
Hittite Empire
Arzawa
Mitanni
Minoan Crete
Mycenaean Greece
Syro-Hittite states
Hayasa-Azzi
Georgia
Anatolia
Armenia
Neo-Assyrian Empire
Urartu
Neo-Babylonian Empire
Medes

Classical antiquity

Greece
Persia (Achaemenid)

Hellenism
Rome
Africa

Late Antiquity

East Asia

China
Korea
Japan

South Asia

Indus Valley
Vedic period
Maha Janapadas
Maurya Empire
Tamilakam
Satavahana
Gupta Empire

Pre-Columbian Americas

Mesoamerica

Olmec
Maya civilization
Teotihuacan
Aztec

Andean civilizations

Chavín culture
Moche
Inca empire

See also

History of the world

Ancient maritime history
Protohistory
Axial Age
Iron Age
Historiography
Ancient literature
Ancient warfare
Cradle of civilization

Followed by the Postclassical Era

v
t
e

text: The earliest signs of a process leading to sedentary culture can be seen in the Levant to as early as 12,000 BC, when the Natufian culture became sedentary; it evolved into an agricultural society by 10,000 BC.[10] The importance of water to safeguard an abundant and stable food supply, due to favourable conditions for hunting, fishing and gathering resources including cereals, provided an initial wide spectrum economy that triggered the creation of permanent villages.[11]

text: The earliest proto-urban settlements with several thousand inhabitants emerged in the Neolithic. The first cities to house several tens of thousands were Memphis and Uruk, by the 31st century BC (see Historical urban community sizes).

text: Historic times are marked apart from prehistoric times when "records of the past begin to be kept for the benefit of future generations";[12] which may be in written or oral form. If the rise of civilization is taken to coincide with the development of writing out of proto-writing, the Near Eastern Chalcolithic, the transitional period between the Neolithic and the Bronze Age during the 4th millennium BC, and the development of proto-writing in Harappa in the Indus Valley of South Asia around 3300 BC are the earliest incidences, followed by Chinese proto-writing evolving into the oracle bone script, and again by the emergence of Mesoamerican writing systems from about 2000 BC.

text: In the absence of written documents, most aspects of the rise of early civilizations are contained in archaeological assessments that document the development of formal institutions and the material culture. A "civilized" way of life is ultimately linked to conditions coming almost exclusively from intensive agriculture. Gordon Childe defined the development of civilization as the result of two successive revolutions: the Neolithic Revolution, triggering the development of settled communities, and the Urban Revolution, which enhanced tendencies towards dense settlements, specialized occupational groups, social classes, exploitation of surpluses, monumental public buildings and writing. Few of those conditions, however, are unchallenged by the records: dense settlements were not attested in Egypt's Old Kingdom and were absent in the Maya area;[citation needed] the Incas lacked writing altogether; and often monumental architecture preceded any indication of village settlement. For instance, in present-day Louisiana, researchers have determined that cultures that were primarily nomadic organized over generations to build earthwork mounds at seasonal settlements as early as 3400 BC. Rather than a succession of events and preconditions, the rise of civilization could equally be hypothesized as an accelerated process that started with incipient agriculture and culminated in the Oriental Bronze Age.[13]

text: Single or multiple cradles[edit]

text: A traditional theory of the spread of civilization is that it began in the Fertile Crescent and spread out from there by influence.[14] Scholars more generally now believe that civilizations arose independently at several locations in both hemispheres. They have observed that sociocultural developments occurred along different timeframes. "Sedentary" and "nomadic" communities continued to interact considerably; they were not strictly divided among widely different cultural groups. The concept of a cradle of civilization has a focus where the inhabitants came to build cities, to create writing systems, to experiment in techniques for making pottery and using metals, to domesticate animals, and to develop complex social structures involving class systems.[5]

text: Current scholarship generally identifies six sites where civilization emerged independently: Mesopotamia, the Nile River, the Indus River, the Yellow River, the Central Andes, and Mesoamerica.[7][15][16][17][18][19][20][21][22]

text: Old World[edit]

text: Mesopotamia[edit]

text: Around 10,200 BC the first fully developed Neolithic cultures belonging to the phases Pre-Pottery Neolithic A (PPNA) and Pre-Pottery Neolithic B (7600 to 6000 BC) appeared in the fertile crescent and from there spread eastwards and westwards.[23] One of the most notable PPNA settlements is Jericho in the Levant region, thought to be the world's first town (settled around 8500 BC and fortified around 6800 BC).[24][25] In Mesopotamia, the convergence of the Tigris and Euphrates rivers produced rich fertile soil and a supply of water for irrigation. The civilizations that emerged around these rivers are among the earliest known non-nomadic agrarian societies. It is because of this that the fertile crescent region, and Mesopotamia in particular, are often referred to as the cradle of civilization.[26] The period known as the Ubaid period (c. 6500 to 3800 BC) is the earliest known period on the alluvial plain, although it is likely earlier periods exist obscured under the alluvium.[27][28] It was during the Ubaid period that the movement towards urbanization began. Agriculture and animal husbandry were widely practiced in sedentary communities, particularly in Northern Mesopotamia, and intensive irrigated hydraulic agriculture began to be practiced in the south.[29] Eridu is the oldest Sumerian site settled during this period, around 5300 BC, and the city of Ur also first dates to the end of this period.[30] In the south, the Ubaid period had a very long duration from around 6500 to 3800 BC; when it is replaced by the Uruk period.[31]

text: Sumerian civilization coalesces in the subsequent Uruk period (4000 to 3100 BC).[32] Named after the Sumerian city of Uruk, this period saw the emergence of urban life in Mesopotamia and, during its later phase, the gradual emergence of the cuneiform script. Proto-writing in the region dates to around 3500 BC, with the earliest texts dating to 3300 BC; early cuneiform writing emerged in 3000 BC.[33] It was also during this period that pottery painting declined as copper started to become popular, along with cylinder seals.[34] Uruk trade networks started to expand to other parts of Mesopotamia and as far as North Caucasus, and strong signs of governmental organization and social stratification began to emerge leading to the Early Dynastic Period (c. 2900 BC).[35][36][37] The earliest ziggurats began near the end of the Early Dynastic Period, although architectural precursors in the form of raised platforms date back to the Ubaid period,[38] and the second phase of the Early Dynastic Period (c. 2700 BC) is also when the legendary king Gilgamesh is believed to have reigned.[39]

text: Eannatum, the Sumerian king of Lagash, established one of the first verifiable empires in history in 2500 BC.[40] The neighboring Elam, in modern Iran, was also part of the early urbanization during the Chalcolithic period.[41] Elamite states were among the leading political forces of the Ancient Near East.[42] The emergence of Elamite written records from around 3000 BC also parallels Sumerian history, where slightly earlier records have been found.[43][44] During the 3rd millennium BC, there developed a very intimate cultural symbiosis between the Sumerians and the Akkadians.[45] Akkadian gradually replaced Sumerian as a spoken language somewhere between the 3rd and the 2nd millennia BC.[46] The Semitic-speaking Akkadian empire emerged around 2350 BC under Sargon the Great.[35] The Akkadian Empire reached its political peak between the 24th and 22nd centuries BC. Under Sargon and his successors, the Akkadian language was briefly imposed on neighboring conquered states such as Elam and Gutium. After the fall of the Akkadian Empire, the Akkadian people of Mesopotamia eventually coalesced into two major Akkadian-speaking nations: Assyria in the north, and, a few centuries later, Babylonia in the south.[47][47][48]

text: Egypt[edit]

text: The developed Neolithic cultures belonging to the phases Pre-Pottery Neolithic A (10,200 BC) and Pre-Pottery Neolithic B (7600 to 6000 BC) appeared in the fertile crescent and from there spread eastwards and westwards.[23] Contemporaneously, a grain-grinding culture using the earliest type of sickle blades had replaced the culture of hunters, fishers, and gathering people using stone tools along the Nile. Geological evidence and computer climate modeling studies also suggest that natural climate changes around 8000 BC began to desiccate the extensive pastoral lands of northern Africa, eventually forming the Sahara. Continued desiccation forced the early ancestors of the Egyptians to settle around the Nile more permanently and to adopt a more sedentary lifestyle.[49] By about 5500 BC, small tribes living in the Nile valley had developed into a series of inter-related cultures as far south as Sudan, demonstrating firm control of agriculture and animal husbandry, and identifiable by their pottery and personal items, such as combs, bracelets, and beads. The largest of these early cultures in upper (Southern) Egypt was the Badari, which probably originated in the Western Desert; it was known for its high quality ceramics, stone tools, and use of copper.[50] The oldest known domesticated bovine in Africa are from Fayum dating to around 4400 BC.[51] The Badari cultures was followed by the Naqada culture, which brought a number of technological improvements.[52] As early as the first Naqada Period, Amratia, Egyptians imported obsidian from Ethiopia, used to shape blades and other objects from flakes.[53] By 3300 BC, just before the first Egyptian dynasty, Egypt was divided into two kingdoms, known as Upper Egypt to the south, and Lower Egypt to the north.[54]

text: Egyptian civilization begins during the second phase of the Naqda culture, known as the Gerzeh period, around 3500 BC and coalesces with the unification of Upper and Lower Egypt around 3150 BC.[55] Farming produced the vast majority of food; with increased food supplies, the populace adopted a much more sedentary lifestyle, and the larger settlements grew to cities of about 5,000 residents. It was in this time that the city dwellers started using mud brick to build their cities, and the use of the arch and recessed walls for decorative effect became popular.[56] Copper instead of stone was increasingly used to make tools[56] and weaponry.[57] Symbols on Gerzean pottery also resemble nascent Egyptian hieroglyphs.[58] Early evidence also exists of contact with the Near East, particularly Canaan and the Byblos coast, during this time.[59] Concurrent with these cultural advances, a process of unification of the societies and towns of the upper Nile River, or Upper Egypt, occurred. At the same time the societies of the Nile Delta, or Lower Egypt, also underwent a unification process. During his reign in Upper Egypt, King Narmer defeated his enemies on the Delta and merged both the Kingdom of Upper and Lower Egypt under his single rule.[60]

text: The Early Dynastic Period of Egypt immediately followed the unification of Upper and Lower Egypt. It is generally taken to include the First and Second Dynasties, lasting from the Naqada III archaeological period until about the beginning of the Old Kingdom, c. 2686 BC.[61] With the First Dynasty, the capital moved from Thinis to Memphis with a unified Egypt ruled by a god-king. The hallmarks of ancient Egyptian civilization, such as art, architecture and many aspects of religion, took shape during the Early Dynastic period. The strong institution of kingship developed by the pharaohs served to legitimize state control over the land, labour, and resources that were essential to the survival and growth of ancient Egyptian civilization.[62] Major advances in architecture, art, and technology were made during the subsequent Old Kingdom, fueled by the increased agricultural productivity and resulting population, made possible by a well-developed central administration.[63] Some of ancient Egypt's crowning achievements, the Giza pyramids and Great Sphinx, were constructed during the Old Kingdom. Under the direction of the vizier, state officials collected taxes, coordinated irrigation projects to improve crop yield, drafted peasants to work on construction projects, and established a justice system to maintain peace and order. Along with the rising importance of a central administration there arose a new class of educated scribes and officials who were granted estates by the pharaoh in payment for their services. Pharaohs also made land grants to their mortuary cults and local temples, to ensure that these institutions had the resources to worship the pharaoh after his death. Scholars believe that five centuries of these practices slowly eroded the economic power of the pharaoh, and that the economy could no longer afford to support a large centralized administration.[61] As the power of the pharaoh diminished, regional governors called nomarchs began to challenge the supremacy of the pharaoh. This, coupled with severe droughts between 2200 and 2150 BC,[64] is assumed to have caused the country to enter the 140-year period of famine and strife known as the First Intermediate Period.[65]

text: India[edit]

text: One of the earliest Neolithic sites in South Asia is Bhirrana along the ancient Saraswati riverine system in the present day state of Haryana in India, dating to around 7600 BC.[66] Other early sites include Lahuradewa in the Middle Ganges region and Jhusi near the confluence of Ganges and Yamuna rivers, both dating to around the 7000 BC.[67][68] The aceramic Neolithic at Mehrgarh lasts from 7000 to 5500 BC, with the ceramic Neolithic at Mehrgarh lasting up to 3300 BC; blending into the Early Bronze Age. Mehrgarh is one of the earliest sites with evidence of farming and herding in South Asia.[69][70] It is likely that the culture centered around Mehrgarh migrated into the Indus Valley and became the Indus Valley Civilisation.[71]

text: The Indus Valley Civilisation starts around 3300 BC with what is referred to as the Early Harappan Phase (3300 to 2600 BC). The earliest examples of the Indus Script date to this period,[72][73] as well as the emergence of citadels representing centralised authority and an increasingly urban quality of life.[74] Trade networks linked this culture with related regional cultures and distant sources of raw materials, including lapis lazuli and other materials for bead-making. By this time, villagers had domesticated numerous crops, including peas, sesame seeds, dates, and cotton, as well as animals, including the water buffalo.[75][76]

text: 2600 BC marks the Mature Harappan Phase during which Early Harappan communities turned into large urban centres including Harappa, Dholavira, Mohenjo-Daro, Lothal, and Rakhigarhi, and more than 1,000 towns and villages, often of relatively small size.[77] Mature Harappans evolved new techniques in metallurgy and produced copper, bronze, lead, and tin and displayed advanced levels of engineering.[78] The ancient Indus systems of sewerage and drainage that were developed and used in cities throughout the Indus region were far more advanced than any found in contemporary urban sites in the Middle East and even more efficient than those in many areas of Pakistan and India today. The advanced architecture of the Harappans is shown by their impressive dockyards, granaries, warehouses, brick platforms, and protective walls. The massive walls of Indus cities most likely protected the Harappans from floods and may have dissuaded military conflicts.[79]

text: Around 1800 BC, signs of a gradual decline began to emerge, and by around 1700 BC most of the cities had been abandoned. Many scholars believe that drought and a decline in trade with Egypt and Mesopotamia caused the collapse of the Indus Civilisation.[80] The migration of Aryan peoples into the region at this time is also notable; however, the idea of a violent invasion is no longer widely accepted.[81] The Indus Valley Civilisation did not disappear suddenly and many elements of the civilisation continue in later South Asian and Vedic cultures.[82]

text: China[edit]

text: Early evidence for Chinese millet agriculture is dated to around 7000 BC,[83] with the earliest evidence of cultivated rice found at Chengtoushan near the Yangtze River, dated to 6500 BC. Chengtoushan may also be the site of the first walled city in China.[84] This Neolithic Revolution gave rise to the Jiahu culture (7000 to 5800 BC).[85] Some scholars have suggested that the Jiahu symbols (6600 BC) are the earliest form of proto-writing in China.[86] However, it is likely that they should not be understood as writing itself, but as features of a lengthy period of sign-use which led eventually to a fully-fledged system of writing.[87] Excavation of a Peiligang culture site in Xinzheng county, Henan, found a community that flourished in 5500 to 4900 BC, with evidence of agriculture, constructed buildings, pottery, and burial of the dead.[88] With agriculture came increased population, the ability to store and redistribute crops, and the potential to support specialist craftsmen and administrators.[85] In late Neolithic times, the Yellow River valley began to establish itself as a center of Yangshao culture (5000 to 3000 BC), and the first villages were founded. Later, Yangshao culture was superseded by the Longshan culture, which was also centered on the Yellow River from about 3000 to 2000 BC.[89] The earliest bronze artifacts have been found in the Majiayao culture site (3100 to 2700 BC).[90][91]

text: Chinese civilization begins during the second phase of the Erlitou period (1900 to 1500 BC), with Erlitou considered the first state level society of East Asia.[92] There is considerable debate whether Erlitou sites correlate to the semi-legendary Xia dynasty. The Xia dynasty (2070 to 1600 BC) is the first dynasty to be described in ancient Chinese historical records such as the Bamboo Annals, first published more than a millennium later during the Western Zhou period. Although Xia is an important element in Chinese historiography, there is to date no archeological evidence to corroborate the dynasty. Erlitou saw an increase in bronze metallurgy and urbanization and was a rapidly growing regional center with palatial complexes that provide evidence for social stratification.[93] The earliest traditional Chinese dynasty for which there is both archeological and written evidence is the Shang dynasty (1600 to 1046 BC). Shang sites have yielded the earliest known body of Chinese writing, the oracle bone script, mostly divinations inscribed on bones. These inscriptions provide critical insight into many topics from the politics, economy, and religious practices to the art and medicine of this early stage of Chinese civilization.[94] Some historians argue that Erlitou should be considered an early phase of the Shang dynasty. The U.S. National Gallery of Art defines the Chinese Bronze Age as the period between about 2000 and 771 BC; a period that begins with the Erlitou culture and ends abruptly with the disintegration of Western Zhou rule.[95] The Sanxingdui culture is another Chinese Bronze Age society, contemporaneous to the Shang dynasty, however they developed a different method of bronze-making from the Shang.[96]

text: The Shang dynasty was succeeded by the Zhou dynasty (1046 to 256 BC). The succession of dynasties, known as the dynastic cycle, is an important political theory in Chinese history. This theory sees a continuity in Chinese history from early times to the present by looking at the succession of empires or dynasties. Emperors would legitimize their rule by invoking the Mandate of Heaven.[97][98] During the Zhou dynasty, Chinese script evolved into its almost-modern form with the use of a clerical script that emerged during the late Warring States period.[99] In 221 BC, China became culturally and politically unified under a large centralized empire, the Qin Dynasty, founded by Emperor Qin Shi Huang Di. Successive dynasties in Chinese history developed bureaucratic systems that enabled the Emperor of China to control the large territory from the center.[100][101]

text: New World[edit]

text: Central Andes[edit]

text: The earliest evidence of agriculture in the Andean region dates to around 4700 BC at Huaca Prieta and Paredones.[102][103][104] The oldest evidence of canal irrigation in South America dates to 4700 to 2500 BC in the Zaña Valley of northern Peru.[105] The earliest urban settlements of the Andes, as well as North and South America, are dated to 3500 BC at Huaricanga, in the Fortaleza area,[5] and Sechin Bajo near the Sechin River.[106][107]

text: The Norte Chico civilization proper is understood to have emerged around 3200 BC, as it is at that point that large-scale human settlement and communal construction across multiple sites becomes clearly apparent.[108] Since the early 21st century, it has been established as the oldest known civilization in the Americas. The civilization flourished at the confluence of three rivers, the Fortaleza, the Pativilca, and the Supe. These river valleys each have large clusters of sites. Further south, there are several associated sites along the Huaura River.[109] Notable settlements include the cities of Caral, the largest and most complex Preceramic site, and Aspero.[110]

text: Norte Chico is unusual in that it completely lacked ceramics and apparently had almost no visual art. Nevertheless, the civilization exhibited impressive architectural feats, including large earthwork platform mounds and sunken circular plazas, and an advanced textile industry.[5][111] The platform mounds, as well as large stone warehouses, provide evidence for a stratified society and a centralized authority necessary to distribute resources such as cotton.[5] However, there is no evidence of warfare or defensive structures during this period.[112] Originally, it was theorized that, unlike other early civilizations, Norte Chico developed by relying on maritime food sources in place of a staple cereal. This hypothesis, the Maritime Foundation of Andean Civilization, is still hotly debated; however, most researches now agree that agriculture played a central role in the civilization's development while still acknowledging a strong supplemental reliance on maritime proteins.[113][114][115]

text: The discovery of quipu, string-based recording devices, at Caral can be understood as a form of "proto-writing" at Norte Chico.[116] However, the exact use of quipu in this and later Andean cultures has been widely debated.[5] Additionally, the image of the Staff God has been found on a gourd dated to 2250 BC. The Staff God is a major deity of later Andean cultures. The presence of quipu and the commonality of religious symbols suggests a cultural link between Norte Chico and later Andean cultures.[117][118]

text: Circa 1800 BC, the Norte Chico civilization began to decline, with more powerful centers appearing to the south and north along the coast and to the east inside the belt of the Andes.[119] Pottery eventually developed in the Amazon Basin and spread to the Andean culture region around 2000 BC. The next major civilization to arise in the Andes would be the Chavín culture at Chavín de Huantar, located in the Andean highlands of the present-day Ancash Region. It is believed to have been built around 900 BC and was the religious and political center of the Chavín people.[120]

text: Mesoamerica[edit]

text: The Coxcatlan caves in the Valley of Tehuacán provide evidence for agriculture in components dated between 5000 and 3400 BC.[121] Similarly, sites such as Sipacate in Guatemala provide maize pollen samples dating to 3500 BC.[122] It is estimated that fully domesticated maize developed in Mesoamerica around 2700 BC.[123] Mesoamericans during this period likely divided their time between small hunting encampments and large temporary villages.[124] What would become the Olmec civilization had its roots in early farming cultures of Tabasco, which began around 5100 to 4600 BC.[125]

text: The emergence of the Olmec civilization has traditionally been dated to around 1600 to 1500 BC. Olmec features first emerged in the city of San Lorenzo Tenochtitlán, fully coalescing around 1400 BC. The rise of civilization was assisted by the local ecology of well-watered alluvial soil, as well as by the transportation network provided by the Coatzacoalcos River basin.[125] This environment encouraged a densely concentrated population, which in turn triggered the rise of an elite class and an associated demand for the production of the symbolic and sophisticated luxury artifacts that define Olmec culture.[126] Many of these luxury artifacts were made from materials such as jade, obsidian, and magnetite, which came from distant locations and suggest that early Olmec elites had access to an extensive trading network in Mesoamerica. The aspect of Olmec culture perhaps most familiar today is their artwork, particularly the Olmec colossal heads.[127]

text: San Lorenzo was all but abandoned around 900 BC at about the same time that La Venta rose to prominence. A wholesale destruction of many San Lorenzo monuments occurred around 950 BC. La Venta continued as the center of Olmec culture until its abandonment around 400 BC; constructing monumental architectural achievements such as the Great Pyramid of La Venta.[127][125] The exact cause of the decline of the Olmec culture is uncertain. Between 400 and 350 BC, the population in the eastern half of the Olmec heartland dropped precipitously.[128] This depopulation was probably the result of serious environmental changes that rendered the region unsuited for large groups of farmers, in particular changes to the riverine environment that the Olmec depended upon for agriculture, hunting and gathering, and transportation. These changes may have been triggered by tectonic upheavals or subsidence, or the silting up of rivers due to agricultural practices.[127][125] Within a few hundred years of the abandonment of the last Olmec cities, successor cultures became firmly established. The Tres Zapotes site, on the western edge of the Olmec heartland, continued to be occupied well past 400 BC, but without the hallmarks of the Olmec culture. This post-Olmec culture, often labeled Epi-Olmec, has features similar to those found at Izapa, some 550 km (330 miles) to the southeast.[129]

text: The Olmecs are sometimes referred to as the mother culture of Mesoamerica, as they were the first Mesoamerican civilization and laid many of the foundations for the civilizations that followed.[130] However, the causes and degree of Olmec influences on Mesoamerican cultures has been a subject of debate over many decades.[131] Practices introduced by the Olmec include ritual bloodletting and the Mesoamerican ballgame; hallmarks of subsequent Mesoamerican societies such as the Maya and Aztec.[130] Although the Mesoamerican writing system would fully develop later, early Olmec ceramics show representations that may be interpreted as codices.[125]

text: Timeline[edit]

text: The following timeline shows the approximate dates of the emergence of civilization (as discussed in the article) in the featured areas and the primary cultures associated with these early civilizations. It is important to note that the timeline is not indicative of the beginning of human habitation, the start of a specific ethnic group, or the development of Neolithic cultures in the area; which often occurred significantly earlier than the emergence of civilization proper.

text: Cradle of Western civilization[edit]

text: There is academic consensus that Classical Greece is the seminal culture which provided the foundation of modern Western culture, democracy, art, theatre, philosophy and science. For this reason it is known as the cradle of Western Civilization.[a] Along with Greece, Rome has sometimes been described as a birthplace or as the cradle of Western Civilization because of the role the city had in politics, republicanism, law, architecture, warfare and Western Christianity.[b]


document_title: Epithelium

question_text: where do we find epithelial cells in humans

text: Epithelium

text: Classification[edit]

text: In general, epithelial tissues are classified by the number of their layers and by the shape and function of the cells.[1][3][4]

text: The three principal shapes associated with epithelial cells are—squamous, cuboidal and columnar.

text:
Squamous epithelium has cells that are wider than their height (flat and scale-like).
Cuboidal epithelium has cells whose height and width are approximately the same (cube shaped).
Columnar epithelium has cells taller than they are wide (column-shaped).

text: By layer, epithelium is classed as either simple epithelium, only one cell thick (unilayered) or stratified epithelium as stratified squamous epithelium, stratified cuboidal epithelium, and stratified columnar epithelium that are two or more cells thick (multi-layered),[5][6] and both types of layering can be made up of any of the cell shapes.[3] However, when taller simple columnar epithelial cells are viewed in cross section showing several nuclei appearing at different heights, they can be confused with stratified epithelia. This kind of epithelium is therefore described as pseudostratified columnar epithelium.[7]

text: Transitional epithelium has cells that can change from squamous to cuboidal, depending on the amount of tension on the epithelium.[8]

text: Simple epithelium[edit]

text: Simple epithelium is a single layer of cells with every cell in direct contact with the basement membrane that separates it from the underlying connective tissue. In general, it is found where absorption and filtration occur. The thinness of the epithelial barrier facilitates these processes.[3]

text: In general, simple epithelial tissues are classified by the shape of their cells. The four major classes of simple epithelium are: (1) simple squamous; (2) simple cuboidal; (3) simple columnar; (4) pseudostratified.[3]

text: Stratified epithelium[edit]

text: Stratified epithelium differs from simple epithelium in that it is multilayered. It is therefore found where body linings have to withstand mechanical or chemical insult such that layers can be abraded and lost without exposing subepithelial layers. Cells flatten as the layers become more apical, though in their most basal layers the cells can be squamous, cuboidal or columnar.[9]

text: Stratified epithelia (of columnar, cuboidal or squamous type) can have the following specializations:[9]

text:
Specialization
Description

Keratinized
In this particular case, the most apical layers (exterior) of cells are dead and lose their nucleus and cytoplasm, instead contain a tough, resistant protein called keratin. This specialization makes the epithelium waterproof, so is found in the mammalian skin. The lining of the esophagus is an example of a non-keratinized or "moist" stratified epithelium.[9]

Parakeratinized
In this case, the most apical layers of cells are filled with keratin, but they still retain their nuclei. These nuclei are pyknotic, meaning that they are highly condensed. Parakeratinized epithelium is sometimes found in the oral mucosa and in the upper regions of the esophagus.[10]

Transitional
Transitional epithelia are found in tissues that stretch and it can appear to be stratified cuboidal when the tissue is not stretched or stratified squamous when the organ is distended and the tissue stretches. It is sometimes called urothelium since it is almost exclusively found in the bladder, ureters and urethra.[9]

text: Cell types[edit]

text: The basic cell types are squamous, cuboidal, and columnar classed by their shape.

text:
Type
Description

Squamous
Squamous cells have the appearance of thin, flat plates that can look polygonal when viewed from above.[11] Their name comes from squāma, Latin for scale – as on fish or snake skin. The cells fit closely together in tissues; providing a smooth, low-friction surface over which fluids can move easily. The shape of the nucleus usually corresponds to the cell form and helps to identify the type of epithelium. Squamous cells tend to have horizontally flattened, nearly oval shaped nuclei because of the thin flattened form of the cell. Squamous epitheliium is found lining surfaces such as the skin, and alveoli in the lung, enabling simple passive diffusion as also found in the alveolar epithelium in the lungs. Specialized squamous epithelium also forms the lining of cavities such as in blood vessels, as endothelium and in the pericardium, as mesothelium and in other body cavities.

Cuboidal
Cuboidal epithelial cells have a cube-like shape and appear square in cross-section. The cell nucleus is large, spherical and is in the centre of the cell. Cuboidal epithelium is commonly found in secretive tissue such as the exocrine glands, or in absorptive tissue such as the pancreas, the lining of the kidney tubules as well as in the ducts of the glands. The germinal epithelium that covers the female ovary, and the germinal epithelium that lines the walls of the seminferous tubules in the testes are also of the cuboidal type. Cuboidal cells provide protection and may be active in pumping material in or out of the lumen, or passive depending on their location and specialisation. Simple cuboidal epithelium commonly differentiates to form the secretory and duct portions of glands.[12] Stratified cuboidal epithelium protects areas such as the ducts of sweat glands,[13] mammary glands, and salivary glands.

Columnar
Columnar epithelial cells are elongated and column-shaped and have a height of at least four times their width. Their nuclei are elongated and are usually located near the base of the cells. Columnar epithelium forms the lining of the stomach and intestines. The cells here may possess microvilli for maximising the surface area for absorption and these microvilli may form a brush border. Other cells may be ciliated to move mucus in the function of mucociliary clearance. Other ciliated cells are found in the fallopian tubes, the uterus and central canal of the spinal cord. Some columnar cells are specialized for sensory reception such as in the nose, ears and the taste buds. Hair cells in the inner ears have stereocilia which are similar to microvilli. Goblet cells are modified columnar cells and are found between the columnar epithelial cells of the duodenum. They secrete mucus, which acts as a lubricant. Single-layered non-ciliated columnar epithelium tends to indicate an absorptive function. Stratified columnar epithelium is rare but is found in lobar ducts in the salivary glands, the eye, pharynx and sex organs. This consists of a layer of cells resting on at least one other layer of epithelial cells which can be squamous, cuboidal, or columnar.

Pseudostratified
These are simple columnar epithelial cells whose nuclei appear at different heights, giving the misleading (hence "pseudo") impression that the epithelium is stratified when the cells are viewed in cross section. Ciliated pseudostratified epithelial cells have cilia. Cilia are capable of energy dependent pulsatile beating in a certain direction through interaction of cytoskeletal microtubules and connecting structural proteins and enzymes. In the respiratory tract the wafting effect produced causes mucus secreted locally by the goblet cells (to lubricate and to trap pathogens and particles) to flow in that direction (typically out of the body). Ciliated epithelium is found in the airways (nose, bronchi), but is also found in the uterus and Fallopian tubes, where the cilia propel the ovum to the uterus.

text: Structure[edit]

text: Cells of epithelial tissue are tightly packed and form a continuous sheet. They have almost no intercellular spaces. All epithelia is usually separated from underlying tissues by an extracellular fibrous basement membrane. The lining of the mouth, lung alveoli and kidney tubules all are made of epithelial tissue. The lining of the blood and lymphatic vessels are of a specialised form of epithelium called endothelium.

text: Location[edit]

text: Epithelium lines both the outside (skin) and the inside cavities and lumina of bodies. The outermost layer of human skin is composed of dead stratified squamous, keratinized epithelial cells.[14]

text: Tissues that line the inside of the mouth, the oesophagus, the vagina, and part of the rectum are composed of nonkeratinized stratified squamous epithelium. Other surfaces that separate body cavities from the outside environment are lined by simple squamous, columnar, or pseudostratified epithelial cells. Other epithelial cells line the insides of the lungs, the gastrointestinal tract, the reproductive and urinary tracts, and make up the exocrine and endocrine glands. The outer surface of the cornea is covered with fast-growing, easily regenerated epithelial cells. A specialised form of epithelium – endothelium forms the inner lining of blood vessels and the heart, and is known as vascular endothelium, and lining lymphatic vessels as lymphatic endothelium. Another type, mesothelium, forms the walls of the pericardium, pleurae, and peritoneum.[citation needed]

text: In arthropods, the integument, or external "skin", consists of a single layer of epithelial ectoderm from which arises the cuticle,[15] an outer covering of chitin the rigidity of which varies as per its chemical composition.

text: Basement membrane[edit]

text: Epithelial tissue rests on a basement membrane, which acts as a scaffolding on which epithelium can grow and regenerate after injuries.[16] Epithelial tissue has a nerve supply, but no blood supply and must be nourished by substances diffusing from the blood vessels in the underlying tissue. The basement membrane acts as a selectively permeable membrane that determines which substances will be able to enter the epithelium.[2]

text: Cell junctions[edit]

text: Cell junctions are especially abundant in epithelial tissues. They consist of protein complexes and provide contact between neighbouring cells, between a cell and the extracellular matrix, or they build up the paracellular barrier of epithelia and control the paracellular transport.[17]

text: Cell junctions are the contact points between plasma membrane and tissue cells. There are mainly 5 different types of cell junctions: tight junctions, adherens junctions, desmosomes, hemidesmosomes, and gap junctions. Tight junctions are a pair of trans-membrane protein fused on outer plasma membrane. Adherens junctions are a plaque (protein layer on the inside plasma membrane) which attaches both cells' microfilaments. Desmosomes attach to the microfilaments of cytoskeleton made up of keratin protein. Hemidesmosomes resemble desmosomes on a section. They are made up of the integrin (a transmembrane protein) instead of cadherin. They attach the epithelial cell to the basement membrane. Gap junctions connect the cytoplasm of two cells and are made up of proteins called connexins (six of which come together to make a connexion).[citation needed]

text: Development[edit]

text: Epithelial tissues are derived from all of the embryological germ layers:[citation needed]

text:
from ectoderm (e.g., the epidermis);
from endoderm (e.g., the lining of the gastrointestinal tract);
from mesoderm (e.g., the inner linings of body cavities).

text: However, it is important to note that pathologists do not consider endothelium and mesothelium (both derived from mesoderm) to be true epithelium. This is because such tissues present very different pathology. For that reason, pathologists label cancers in endothelium and mesothelium sarcomas, whereas true epithelial cancers are called carcinomas. Also, the filaments that support these mesoderm-derived tissues are very distinct. Outside of the field of pathology, it is, in general, accepted that the epithelium arises from all three germ layers.[citation needed]

text: Functions[edit]

text: Epithelial tissues have as their primary functions:

text:
to protect the tissues that lie beneath from radiation, desiccation, toxins, invasion by pathogens, and physical trauma
the regulation and exchange of chemicals between the underlying tissues and a body cavity
the secretion of hormones into the circulatory system, as well as the secretion of sweat, mucus, enzymes, and other products that are delivered by ducts[18]
to provide sensation[19]

tag: ol

text: Glandular tissue[edit]

text: Glandular tissue is the type of epithelium that forms the glands from the infolding of epithelium and subsequent growth in the underlying connective tissue. There are two major classifications of glands: endocrine glands and exocrine glands:

text:
Endocrine glands secrete their product into the extracellular space where it is rapidly taken up by the circulatory system.
Exocrine glands secrete their products into a duct that then delivers the product to the lumen of an organ or onto the free surface of the epithelium.

text: Sensing the extracellular environment[edit]

text: "Some epithelial cells are ciliated, especially in respiratory epithelium, and they commonly exist as a sheet of polarised cells forming a tube or tubule with cilia projecting into the lumen." Primary cilia on epithelial cells provide chemosensation, thermoception, and mechanosensation of the extracellular environment by playing "a sensory role mediating specific signalling cues, including soluble factors in the external cell environment, a secretory role in which a soluble protein is released to have an effect downstream of the fluid flow, and mediation of fluid flow if the cilia are motile."[20]

text: Clinical significance[edit]

text: The slide shows at (1) an epithelial cell infected by Chlamydia pneumonia; their inclusion bodies shown at (3); an uninfected cell shown at (2) and (4) showing the difference between an infected cell nucleus and an uninfected cell nucleus.

text: Epithelium grown in culture can be identified by examining its morphological characteristics. Epithelial cells tend to cluster together, and have a "characteristic tight pavement-like appearance". But this is not always the case, such as when the cells are derived from a tumor. In these cases, it is often necessary to use certain biochemical markers to make a positive identification. The intermediate filament proteins in the cytokeratin group are almost exclusively found in epithelial cells, and so are often used for this purpose.[21]

text: Carcinomas develop in epithelial tissues. Sarcomas develop in connective tissue.[22]

text: When epithelial cells or tissues are damaged from cystic fibrosis, sweat glands are also damaged, causing a frosty coating of the skin.

text: Etymology and pronunciation[edit]

text: The word epithelium (/ˌɛpɪˈθiːliəm/) uses the Greek roots ἐπί (epi), "on" or "upon", and θηλή (thēlē), "nipple". Epithelium is so called because the name was originally used to describe the translucent covering of small "nipples" of tissue on the lip.[23] The word has both mass and count senses; the plural form is epithelia.

text: Additional images[edit]

text:
Squamous Epithelium 100x

Human cheek cells (Nonkeratinized stratified squamous epithelium) 500x

Histology of female urethra showing transitional epithelium

Histology of sweat gland showing stratified cuboidal epithelium