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== Heading text ==
{{Short description|Entire structure of a human being}}
{{short description|German animation studio and YouTube channel}}
{{Redirect|Anatomy of the human body|the textbook|Gray's Anatomy}}
{{Use mdy dates|date=May 2019|cs1-dates=l}}
{{Pp-move-indef|small=yes}}
{{Infobox organization
{{Use dmy dates|date=April 2020}}
| name = Kurzgesagt
[[File:Human Body 02.png|thumb|Female (left) and male (right) adult human bodies photographed in ventral (above) and dorsal (below) perspectives. Naturally-occurring [[pubic hair|pubic]], [[body hair|body]], and [[facial hair]] has been [[Hair removal|deliberately removed]] to show anatomy.]]
| logo = Kurzgesagt.png
| logo_alt = a blue circle with white and green lines on it, surrounded by lighter blue halos
| logo_size = 200
| logo_caption = Kurzgesagt's logo, a minimalist representation of Earth
| motto = In a Nutshell
| formation = {{start date and age|2013|07|09}}
| full_name = Kurzgesagt - In a Nutshell
| pronounce = /ˌkʊərtsɡəˈzɑːkt/
| founder = Philipp Dettmer
| type = [[Privately held company|Private]] [[Gesellschaft mit beschränkter Haftung|GmbH]]
| purpose = [[Edutainment]]
| location = [[Munich]], Germany<ref>{{cite web |url=https://www.cnet.com/news/the-ultimate-guide-to-black-holes-will-spaghettify-your-brain/ |title=The 'ultimate guide to black holes' will spaghettify your brain |last=Jackson |first=Ryan |date=April 28, 2021 |work=[[CNET]] |archive-url=https://web.archive.org/web/20210429143806/https://www.cnet.com/news/the-ultimate-guide-to-black-holes-will-spaghettify-your-brain/ |archive-date=April 29, 2021 |url-status=live}}</ref>
| owner = Philipp Dettmer
| staff = 64<ref name="About">{{Cite web|url=https://kurzgesagt.org/about/|title=About|work=Kurzgesagt|language=en|access-date=March 28, 2023}}</ref>
| staff_year = 2023
| website = {{URL|kurzgesagt.org/|kurzgesagt.org}}
| footnotes = {{Infobox YouTube personality|embed=yes
| channel_name = Kurzgesagt
| channel_display_name = Kurzgesagt – In a Nutshell
| years_active = 2013–present
| genre = {{Hlist|Animation|Education|Science|Philosophy}}
| subscribers = 20.5 million
| views = 2.30 billion
| silver_button = yes
| silver_year = 2014
| gold_button = yes
| gold_year = 2015
| diamond_button = yes
| diamond_year = 2019
| stats_update = May 16 2023
}}
}}T
== TROLL BY THE KCA ==
'''Kurzgesagt''' ({{IPAc-en|ˌ|k|ʊər|t|s|g|ə|ˈ|z|ɑː|k|t}}; [[German language|German]] for "In a nutshell", "Long story short" or "in short" (with "in a few words" also being a possible but less common translation in [[English language|English]]) is a German-made [[animation studio|animation]] and [[design studio]] founded by Philipp Dettmer. The studio's [[YouTube|YouTube channel]] focuses on [[Minimalism|minimalistic]] animated educational content,<ref>{{Cite journal |last1=Lucas |first1=Terry |last2=Abd Rahim |first2=Ruslan |date=March 15, 2017 |title=The Similarities and Nuances of Explicit Design Characteristics of Well-Received Online Instructional Animations |url=http://journals.sagepub.com/doi/10.1177/1746847717690671 |journal=[[Animation (journal)|Animation]] |language=en |publisher=[[SAGE Publishing]] |volume=12 |issue=1 |pages=80–99 |doi=10.1177/1746847717690671 |s2cid=64818185 |issn=1746-8477}}</ref> using a [[Flat design|flat]] and [[3D computer graphics|3D design style]]. It discusses [[Science|scientific]], [[Technology|technological]], [[Politics|political]], [[Philosophy|philosophical]], and [[Psychology|psychological]] subjects.<ref>{{Cite journal |last1=Dubovi |first1=Ilana |last2=Tabak |first2=Iris |date=2020-10-01 |title=An empirical analysis of knowledge co-construction in YouTube comments |url=https://www.sciencedirect.com/science/article/pii/S0360131520301378 |journal=Computers & Education |language=en |publisher=[[Elsevier]] |volume=156 |pages=7 |doi=10.1016/j.compedu.2020.103939 |s2cid=219914081 |issn=0360-1315}}</ref>


Narrated by Steve Taylor, videos on the channel are normally four to sixteen minutes. Many videos are also available through other language-specific channels, such as in German through the channel ''Dinge Erklärt – Kurzgesagt,'' and in [[Spanish language|Spanish]] through ''En Pocas Palabras - Kurzgesagt.'' Some of their videos are also available in [[French language|French]], [[Hindi]], [[Arabic]], [[Brazilian Portuguese]], [[Japanese language|Japanese]] and [[Korean language|Korean]].<ref>{{Cite web |title=Dinge Erklärt – Kurzgesagt |url=https://www.youtube.com/user/KurzgesagtDE |access-date=2022-03-19 |website=[[YouTube]]}}</ref><ref>{{Cite web |title=Kurzgesagt – In a Nutshell |url=https://www.youtube.com/c/inanutshell/channels |access-date=2022-07-30 |website=[[YouTube]]}}</ref>
The '''human body''' is the structure of a [[Human|human being]]. It is composed of many different types of [[Cell (biology)|cells]] that together create [[Tissue (biology)|tissues]] and subsequently [[organ systems]]. They ensure [[homeostasis]] and the [[life|viability]] of the human body.


As of 25 May 2023, with over 20 million subscribers and over 180 videos, the studio's original English language channel was the world's 207th most subscribed channel.<ref>{{Cite web |title=Kurzgesagt – In a Nutshell |url=https://socialblade.com/youtube/user/kurzgesagt |access-date=1 May 2023 |website=[[Social Blade]]}}</ref>
It comprises a [[human head|head]], [[hair]], [[neck]], [[Trunk (anatomy)|trunk]] (which includes the [[thorax]] and [[abdomen]]), [[arm]]s and [[hands]], [[human leg|legs]] and [[feet]].


== History ==
The study of the human body involves [[anatomy]], [[physiology]], [[histology]] and [[embryology]]. The body [[anatomical variability|varies anatomically]] in known ways. Physiology focuses on the systems and organs of the human body and their functions. Many systems and mechanisms interact in order to maintain [[homeostasis]], with safe levels of substances such as sugar and [[oxygen]] in the blood.
[[File:Patrizia Mosca COO & Executive Producer, Kurzgesagt 2018.jpg|thumb|Patrizia Mosca, Chief operating officer at Kurzgesagt, speaks at [[The Internet Foundation in Sweden|the Internet Days]] in Stockholm, 2018.]]
The Kurzgesagt YouTube channel was created on 9 July 2013, shortly after the founder, Philipp Dettmer, graduated from [[Munich University of Applied Sciences]].<ref>{{Cite web |last=Brien |first=Jörn |date=2019-11-06 |title=Youtube: Kurzgesagt – In a Nutshell knackt als erster deutscher Kanal die 10-Millionen-Marke |trans-title=Youtube: In a nutshell – In a Nutshell is the first German channel to break the 10 million mark |url=https://t3n.de/news/youtube-kurzgesagt-in-nutshell-1215899/ |access-date=November 3, 2019 |website=t3n Magazin |language=de}}</ref> The first video, which explained [[evolution]], was published two days later with the voice of Steve Taylor, who still serves as commentator as of 2023.<ref>{{Cite web |title=English Voice - Voice Pool English Voice-Over |url=http://voice-pool.com/en/english/ |access-date=2022-10-17 |website=Voice Pool |language=en-GB}}</ref> The videos were much more popular than expected, and in six years the channel went from a project worked on during Dettmer's free time to a design studio with over forty employees. The studio has even received commissions and grants from a number of established, independent institutions.{{Citation needed|date=July 2022}}
In 2015, Kurzgesagt was commissioned to create a video on the end of disease by the [[Bill and Melinda Gates Foundation]].<ref name=":3">{{Cite web |date=November 2015 |title=Kurzgesagt |url=https://www.gatesfoundation.org/about/committed-grants/2015/11/opp1139276 |access-date=2021-03-14 |website=Bill & Melinda Gates Foundation |language=en}}</ref>


This video about the [[COVID-19 pandemic]], called ''The Coronavirus Explained & What You Should Do'' and released in March 2020, was posted on all three of their channels and shared how the human body responds to [[COVID-19]] and how effective the measures in evading [[SARS-CoV-2]].<ref>{{Cite web |last=Hart |first=Matthew |date=2020-05-19 |title=A Look at How the Virus that Causes COVID-19 Infects People |url=https://nerdist.com/article/how-coronavirus-covid-19-infects-people/ |website=[[Nerdist]]}}</ref> The English version has over 88 million views, making it the most viewed video on the channel.<ref>{{Cite web |date=2020-03-26 |title=Video explainer on the coronavirus has more than 17.5 million views |url=https://www.cochranetoday.ca/local-news/video-explainer-on-the-coronavirus-has-more-than-175-million-views-2203874 |website=Cochrane Today}}</ref> A study published in ''[[Visual Resources]]'', said that the video "is an example of an aesthetically compelling explanation of the biological processes of a Covid infection" and it "includes fantastical depictions that convey the message in a more comprehensible straightforward manner."<ref>{{Cite journal |last=Ehrlich |first=Nea |date=2020-07-02 |title=Viral Imagery: The Animated Face of Covid-19 |url=https://doi.org/10.1080/01973762.2021.1960777 |journal=[[Visual Resources]] |publisher=[[Routledge]] |volume=36 |issue=3 |pages=247–261 |doi=10.1080/01973762.2021.1960777 |s2cid=241823806 |issn=0197-3762}}</ref>
The body is studied by [[health professional]]s, physiologists, anatomists, and artists to assist them in their work.


Outside of the grants from patrons, Kurzgesagt, at least the German branch, was primarily financially supported by the network [[Funk (service)|Funk]] of [[ARD (broadcaster)|ARD]] and [[ZDF]] since September 2017. Kurzgesagt's German Branch announced their departure from Funk in January 2023.<ref>{{Cite web |last= |first= |date=2020-11-18 |title=funk-Format 'Kurzgesagt' fragt: 'Brauchen wir Atomkraft, um den Klimawandel zu stoppen?' |trans-title=funk-format 'In a nutshell' asks: 'Do we need nuclear power to stop climate change?' |url=https://www.braunschweiger-zeitung.de/wirtschaft/presseportal/article230944944/funk-Format-Kurzgesagt-fragt-Brauchen-wir-Atomkraft-um-den-Klimawandel-zu-stoppen.html |url-status=dead |archive-url=https://web.archive.org/web/20210122025902/https://www.braunschweiger-zeitung.de/wirtschaft/presseportal/article230944944/funk-Format-Kurzgesagt-fragt-Brauchen-wir-Atomkraft-um-den-Klimawandel-zu-stoppen.html |archive-date=January 22, 2021 |access-date=2020-11-21 |website=[[Braunschweiger Zeitung]] |language=de-DE}}</ref><ref>{{Cite web |last1=Fehrensen |first1=Täubner |last2=Täubner |first2=Mischa |year=2019 |title=Acht Minuten Welterklärung - brand eins online |trans-title=Eight minutes of explanation of the world |url=https://www.brandeins.de/magazine/brand-eins-wirtschaftsmagazin/2019/qualitaet/acht-minuten-welterklaerung |url-status=live |archive-url=https://web.archive.org/web/20210301190117/https://www.brandeins.de/magazine/brand-eins-wirtschaftsmagazin/2019/qualitaet/acht-minuten-welterklaerung |archive-date=March 1, 2021 |access-date=August 4, 2021 |website=brand eins |language=German}}</ref><ref>{{Cite web |last=Lux |first=Torben |date=2020-06-17 |title=So hat Kurzgesagt-Gründer Philipp Dettmer mit Erklärvideos eine Milliarde Views gemacht |trans-title=Kurzgesagt founder Philipp Dettmer has made a billion views with explanatory videos |url=https://omr.com/de/podcast-kurzgesagt-in-a-nutshell-philipp-dettmer/ |access-date=2020-11-21 |website=ORM |language=de-DE}}</ref><ref>{{Cite web |last=Dinge Erklärt - Kurzgesagt |date=2023-01-19 |title=Warum wir funk verlassen haben! |trans-title=Why we left funk! |url=https://m.youtube.com/watch?v=xK-FEU4VowY |access-date=2023-01-19 |website=YouTube |language=de}}</ref>
{{TOC level|3}}


Kurzgesagt has been the recipient of several awards. In 2019, Kurzgesagt became the first German channel to surpass 10 million subscribers on YouTube.<ref>{{Cite web|last1=Weil|first1=Andrew|date=December 5, 2019|title=YouTube's 2019 Rewind focuses on the basics after 2018 video fiasco|url=https://www.wusa9.com/article/news/nation-world/youtubes-2019-rewind-focuses-on-the-basics-after-2018-video-blowback/507-c8026f03-717f-49ee-9914-03bd55657d7d|access-date=February 27, 2020|website=Wusa9}}</ref> In December 2020, fellow YouTuber [[Marques Brownlee]] honored Kurzgesagt, with his "Streamys Creator Honor" award in the [[10th Streamy Awards]].<ref>{{cite web |url=https://www.tubefilter.com/2020/12/12/here-are-your-2020-streamy-award-winners/ |title=Here Are Your 2020 Streamy Award Winners |first=James |last=Hale |date=December 12, 2020 |work=Tubefilter}}</ref>
==Composition==
{{Main|Composition of the human body}}
{| class="wikitable floatright" style="font-size: 86%"
|+ align="bottom" style="text-align:left; caption-side: bottom" | Elements of the human body by mass. [[Trace elements]] are less than 1% combined (and each less than 0.1%).
| rowspan="13"|[[File:201 Elements of the Human Body.02.svg|300px]]
| style="width: 50pt;"| '''Element'''
| style="width: 10pt; text-align:center;"|'''Symbol'''
| style="width: 20pt; text-align:center;"| '''Percent mass'''
| style="width: 20pt; text-align:center;"| '''Percent atoms'''
|-
| Oxygen
| style="text-align:center;"|O
| style="text-align:right;"|65.0
| style="text-align:right;"|24.0
|-
| Carbon
| style="text-align:center;"|C
| style="text-align:right;"|18.5
| style="text-align:right;"|12.0
|-
| Hydrogen
| style="text-align:center;"|H
| style="text-align:right;"|9.5
| style="text-align:right;"|62.0
|-
| Nitrogen
| style="text-align:center;"|N
| style="text-align:right;"|3.2
| style="text-align:right;"|1.1
|-
| Calcium
| style="text-align:center;"|Ca
| style="text-align:right;"|1.5
| style="text-align:right;"|0.22
|-
| Phosphorus
| style="text-align:center;"|P
| style="text-align:right;"|1.0
| style="text-align:right;"|0.22
|-
| Potassium
| style="text-align:center;"|K
| style="text-align:right;"|0.4
| style="text-align:right;"|0.03
|-
| Sulfur
| style="text-align:center;"|S
| style="text-align:right;"|0.3
| style="text-align:right;"|0.038
|-
| Sodium
| style="text-align:center;"|Na
| style="text-align:right;"|0.2
| style="text-align:right;"|0.037
|-
| Chlorine
| style="text-align:center;"|Cl
| style="text-align:right;"|0.2
| style="text-align:right;"|0.024
|-
| Magnesium
| style="text-align:center;"|Mg
| style="text-align:right;"|0.1
| style="text-align:right;"|0.015
|-
| Trace elements
|
| style="text-align:right;"|< 0.1
| style="text-align:right;"|< 0.3
|}


=== ''Immune: A journey into the mysterious system that keeps you alive'' ===
The [[composition of the human body|human body is composed of]] [[chemical element|elements]] including [[hydrogen]], [[oxygen]], [[carbon]], [[calcium]] and [[phosphorus]].<ref name="AboutChemical">{{Cite web |url=http://chemistry.about.com/od/chemicalcomposition/a/Chemical-Composition-Of-The-Human-Body.htm |title=Chemical Composition of the Human Body |publisher=[[About education]] |access-date=2 September 2016 |archive-date=11 February 2017 |archive-url=https://web.archive.org/web/20170211225934/http://chemistry.about.com/od/chemicalcomposition/a/Chemical-Composition-Of-The-Human-Body.htm |url-status=dead }}</ref> These elements reside in trillions of cells and non-cellular components of the body.
In November 2021, Kurzgesagt announced the release of their first book, ''Immune: A journey into the mysterious system that keeps you alive'', written by Phillip Dettmer, the channel's founder.<ref>{{Cite web |last=Kurzgesagt – In a Nutshell |date=2021-08-10 |title=How The Immune System ACTUALLY Works – IMMUNE |url=https://www.youtube.com/watch?v=lXfEK8G8CUI |access-date=2022-09-18 |website=YouTube}}</ref>


A publication by the [[Foundation for the Rights of Future Generations]], a German think tank, recommended the book among others for books on the [[COVID-19 pandemic]], describing it as "full of stories of invasion, strategy, defeat, and noble self-sacrifice," in introducing the complex world of the [[immune system]].<ref>{{Cite journal |last=Tremmel |first=Jörg |date=2021 |title=Recommendations of new books on the pandemic |url=https://www.igjr.org/ojs/index.php/igjr/article/view/912 |journal=Intergenerational Justice Review |language=en |volume=7 |issue=1 |doi=10.24357/igjr.7.1.912 |issn=2190-6335}}</ref> [[Daniel M. Davis]], the Head of Life Sciences and Professor of Immunology at [[Imperial College London]], described it as "the feast we have been waiting for" due to the public interest in the mechanisms of the immune system, such as [[Antibody|Antibodies]], [[T cell]]s, and [[B cell]]s, during the COVID-19 pandemic, which were "rarely discussed outside of research labs and scientific talks."<ref>{{Cite journal |last=Davis |first=Daniel M. |date=2021-11-05 |title=Immunology meets the masses Immune: A Journey into the Mysterious System That Keeps You Alive Philipp Dettmer Random House, 2021. 368 pp. |url=https://www.science.org/doi/10.1126/science.abm0134 |journal=Science |language=en |volume=374 |issue=6568 |pages=697 |doi=10.1126/science.abm0134 |pmid=34735237 |s2cid=243761609 |issn=0036-8075}}</ref> In the book, the author acknowledges the feedback and help of a Dr. James Gurney, Professor Thomas Brocker, the director of the Munich Institute for Immunology, and Professor Maristela Martins de Camargo of the [[University of São Paulo]].<ref>{{Cite book |last=Dettmer |first=Philipp |title=Immune : a journey into the mysterious system that keeps you alive |date=November 2, 2021 |isbn=978-0593241332}}</ref>
The adult male body is about 60% [[body water|water]] for a total water content of some {{convert|42|litre}}. This is made up of about {{convert|19|litres}} of [[extracellular fluid]] including about {{convert|3.2|litre}} of blood plasma and about {{convert|8.4|litre}} of [[interstitial fluid]], and about {{convert|23|litre}} of fluid inside cells.<ref>{{Cite web|title=Fluid Physiology|url=http://www.anaesthesiamcq.com/FluidBook/fl2_1.php|website=Anaesthesiamcq|url-status=dead|archive-url=https://web.archive.org/web/20050503083706/http://www.anaesthesiamcq.com/FluidBook/fl2_1.php|archive-date=3 May 2005|access-date=2 September 2016}}</ref> The content, acidity and composition of the water inside and outside cells is carefully maintained. The main electrolytes in body water outside cells are [[sodium]] and [[chloride]], whereas within cells it is [[potassium]] and other [[phosphate]]s.{{sfn|Ganong's|2016|p=5}}


===Cells===
===Sources of funding===
In 2015, the channel received a 570,000 US dollar grant from the [[Bill and Melinda Gates Foundation]]<ref name=":3" /> who later became one of their key sponsors. Kurzgesagt have made videos calling for investment in novel technologies the foundation also supports, such as [[Carbon sequestration|carbon capture]] and [[Meat analogue|artificial meat]], as well as arguing for an optimistic view on the future of [[climate change]] and [[economic inequality]], a view shared by [[Bill Gates]].<ref>{{cite news |last=Rathi |first=Akshat |date=2 February 2022 |title=Bill Gates Invests in Carbon Capture Startup After Tech Breakthrough |language=en |work=[[Bloomberg.com]] |url=https://www.bloomberg.com/news/articles/2022-02-02/new-tech-could-cut-carbon-capture-energy-use-by-70 |access-date=29 January 2023}}</ref><ref>{{cite news |last1=Morgan |first1=Rick |date=23 March 2018 |title=Bill Gates and Richard Branson are betting lab-grown meat might be the food of the future |language=en |work=[[CNBC]] |url=https://www.cnbc.com/2018/03/23/bill-gates-and-richard-branson-bet-on-lab-grown-meat-startup.html |access-date=29 January 2023}}</ref>
{{See also|List of distinct cell types in the adult human body}}
The body contains trillions of [[Cell (biology)|cells]], the fundamental unit of life.<ref>{{Cite web |url=http://sciencenetlinks.com/student-teacher-sheets/cells-your-body/ |title=The Cells in Your Body |publisher=Science Netlinks |access-date=2 September 2016}}</ref> At maturity, there are roughly 30<ref name="sender-et-al">{{Cite journal |last1=Sender |first1=Ron |last2=Fuchs |first2=Shai |last3=Milo |first3=Ron |year=2016 |title=Revised estimates for the number of human and bacteria cells in the body |journal=PLOS Biology |volume=14 |issue=8 |pages=e1002533 |biorxiv=10.1101/036103 |doi=10.1371/journal.pbio.1002533 |pmc=4991899 |pmid=27541692}}</ref>{{ndash}}37<ref>{{Cite journal |last1=Bianconi |first1=Eva |last2=Piovesan |first2=Allison |last3=Facchin |first3=Federica |last4=Beraudi |first4=Alina |last5=Casadei |first5=Raffaella |last6=Frabetti |first6=Flavia |last7=Vitale |first7=Lorenza |last8=Pelleri |first8=Maria Chiara |last9=Tassani |first9=Simone |last10=Piva |first10=Francesco |last11=Perez-Amodio |first11=Soledad |last12=Strippoli |first12=Pierluigi |last13=Canaider |first13=Silvia|date=5 July 2013 |title=An estimation of the number of cells in the human body. |url=https://semanticscholar.org/paper/41c3dfda0d261070d84a2070c8b70b1f86cab52d |journal=[[Annals of Human Biology]] |volume=40 |issue=6 |pages=463–471 |doi=10.3109/03014460.2013.807878 |pmid=23829164 |hdl=11585/152451 |s2cid=16247166 }}</ref>{{nbsp}}trillion cells in the body, an estimate arrived at by totaling the cell numbers of all the [[organ (biology)|organs]] of the body and [[List of distinct cell types in the adult human body|cell types]]. The body is also host to about the same number of non-human cells<ref name="sender-et-al" /> as well as [[Multicellular|multicellular organisms]] which reside in the [[gastrointestinal tract]] and on the [[skin]].<ref name="Fredericks">{{Cite journal |first=David N. |last=Fredricks |year=2001 |title=Microbial Ecology of Human Skin in Health and Disease |journal=Journal of Investigative Dermatology Symposium Proceedings |volume=6 |issue=3 |pages=167–169 |doi=10.1046/j.0022-202x.2001.00039.x |pmid=11924822|s2cid=34741925 |doi-access=free }}</ref> Not all parts of the body are made from cells. Cells sit in an [[extracellular matrix]] that consists of [[protein]]s such as [[collagen]], surrounded by extracellular fluids. Of the {{cvt|70|kg|lb}} weight of an average human body, nearly {{cvt|25|kg|lb}} is non-human cells or non-cellular material such as [[bone]] and [[connective tissue]].


In March 2022, Kurzgesagt received 2.97 million [[euros]] in a grant via [[Open Philanthropy (organization)|Open Philanthropy]],<ref>{{cite web |date= |title=Grants |url=https://www.openphilanthropy.org/grants/?organization-name=kurzgesagt |access-date=29 January 2023 |website=[[Open Philanthropy]] |language=en-us}}</ref> which the channel said was being used for translating their videos to various languages, and for funding the creation of content for [[TikTok]].<ref name="reddit.com">{{cite web |date=23 January 2023 |title=Kurzgesagt Statement to the Conflict of Interest Allegations |url=https://reddit.com/r/kurzgesagt/comments/10jlyyk/kurzgesagt_statement_to_the_conflict_of_interest/ |access-date=29 January 2023 |website=[[reddit]] |language=en}}</ref> Open Philanthropy supports positions that Kurzgesagt has defended, such as [[effective altruism]] and [[Longtermism]].<ref>{{cite web |date=18 July 2022 |title=Kurzgesagt — Short-form Video Content |url=https://www.openphilanthropy.org/grants/kurzgesagt-short-form-video-content/ |access-date=29 January 2023 |website=[[Open Philanthropy]] |language=en-us}}</ref> The channel has received a smaller grant from the [[John Templeton Foundation]].<ref>{{cite web |title=An Analysis of the Distribution of Degrees of Intelligence across Animal Groups |url=https://www.templetonworldcharity.org/projects-database/0266 |access-date=29 January 2023 |website=Templeton World Charity |publisher= |language=en}}</ref>
====Genome====
{{Main|Genome}}
{{See also|Genetics}}


In a January 2023 statement,<ref name="reddit.com2">{{cite web |title=Kurzgesagt Statement to the Conflict of Interest Allegations |url=https://reddit.com/r/kurzgesagt/comments/10jlyyk/kurzgesagt_statement_to_the_conflict_of_interest/ |access-date=29 January 2023 |website=reddit |language=en}}</ref> Kurzgesagt stated that 65% of their income from 2020 to 2022 came from viewers via the sale of merchandise from their shop, such as [[mugs]], [[posters]] and [[toys]], [[crowdfunding]] via [[Patreon]], and [[Google AdSense]] revenue, with commercial or institutional [[sponsorships]], and [[Grant (money)|grants]] accounting for only 24% of income. The statement said that the channel treats all data skeptically, that their sources for statements are always given, and that all research work is done in-house, with no editorial influence from sponsors or donors—a condition they say is included in every deal they have signed.<ref name="reddit.com2"/>
Cells in the body function because of [[DNA]]. DNA sits within the [[Cell nucleus|nucleus of a cell]]. Here, parts of DNA are [[transcription (genetics)|copied]] and sent to the body of the cell via [[RNA]].{{sfn|Ganong's|2016|p=16}} The RNA is then used to [[translation (biology)|create]] [[protein]]s which form the basis for cells, their activity, and their products. Proteins dictate cell function and gene expression, a cell is able to self-regulate by the amount of proteins produced.<ref>{{Cite web|title=Gene Expression {{!}} Learn Science at Scitable|url=http://www.nature.com/scitable/topicpage/gene-expression-14121669|website=www.nature.com|language=en|url-status=dead|archive-url=https://web.archive.org/web/20101031053632/http://www.nature.com/scitable/topicpage/gene-expression-14121669|archive-date=31 October 2010|access-date=29 July 2017}}</ref> However, not all cells have DNA; some cells such as mature [[red blood cells]] lose their nucleus as they mature.


===Tissues===
=== Reliability of videos ===
While some commentators have praised Kurzgesagt's videos for their reliability and fact-checking,<ref>{{Cite web |last=Humprhies |first=Suzanne |date=January 9, 2021 |title=What We're Watching: Kurzgesagt Explores Big Questions with Bite-Size Videos|url=https://www.reviewgeek.com/66657/what-were-watching-kurzgesagt-explores-big-questions-with-bite-size-videos/ |work=Review Geek |language=en-US |archive-url=https://web.archive.org/web/20210418080815/https://www.reviewgeek.com/66657/what-were-watching-kurzgesagt-explores-big-questions-with-bite-size-videos/ |archive-date=April 18, 2021 |url-status=live}}</ref> some of their earlier work received criticism. In 2016, the [[Art Libraries Society of North America]] criticized the studio's occasional lack of credible sources and professional consultation, and use of emotive language.<ref name=":2">{{Cite web |last=Gumb |first=Lindsey |date=April 2016 |title=Multimedia Technology Review — Kurzgesagt |url=https://arlisna.org/publications/multimedia-technology-reviews/897-kurzgesagt |url-status=live |archive-url=https://web.archive.org/web/20210415152829/https://arlisna.org/publications/multimedia-technology-reviews/897-kurzgesagt |archive-date=April 15, 2021 |website=[[Art Libraries Society of North America]]}}</ref>
{{external media | width = 210px | float = right | headerimage=[[File:2120 Major Systemic Artery.jpg|210px]] | video1 = [https://www.youtube.com/watch?v=Ae4MadKPJC0 Human Body 101], ''[[National Geographic]]'', 5:10 | accessdate =3 December 2017 }}


In 2019, Kurzgesagt released a video saying that while they now had all their arguments fact-checked by experts, they had not always done so in the past. They added they were deleting two of their videos from 2015 that failed their current standards, including their video titled "Addiction".<ref name=":0">{{Citation|title=Can You Trust Kurzgesagt Videos?|url=https://www.youtube.com/watch?v=JtUAAXe_0VI|work=Kurzgesagt channel on [[YouTube]] |language=en|access-date=June 26, 2021}}</ref> A collaboration between Kurzgesagt and journalist [[Johann Hari]], "Addiction" came to be one of the most popular on their channel at the time, despite also being one of their most criticized.<ref name=":1">{{Cite web |last=Stenn |first=Lili |date=March 14, 2019 |title=YouTuber Coffee Break Accuses Kurzgesagt of Being Untrustworthy, Founder Responds |url=https://roguerocket.com/2019/03/13/youtuber-coffee-break-accuses-kurzgesagt-of-being-untrustworthy-founder-responds/ |archive-url= https://web.archive.org/web/20210423085525/https://roguerocket.com/2019/03/13/youtuber-coffee-break-accuses-kurzgesagt-of-being-untrustworthy-founder-responds/ |archive-date=April 23, 2021 |website=Rogue Rocket |language=en-US |url-status=live}}</ref> The video was accused of misleadingly summarizing the conclusions of the contentious [[Rat Park|Rat Park experiments]].<ref name=":1"/> Kurzgesagt acknowledged they had presented one argument as fact, and had not considered other theories on the matter.<ref name=":0"/>
The body consists of many different types of [[Tissue (biology)|tissue]], defined as cells that act with a specialised function.<ref>{{Cite web |url=https://en.oxforddictionaries.com/definition/tissue |archive-url=https://web.archive.org/web/20161005004435/https://en.oxforddictionaries.com/definition/tissue |url-status=dead |archive-date=5 October 2016 |title=tissue – definition of tissue in English |work=[[Oxford Dictionaries (website)|Oxford Dictionaries]]{{!}} English |access-date=17 September 2016}}</ref> The study of tissues is called [[histology]] and often occurs with a [[microscope]]. The body consists of four main types of tissues. These are lining cells ([[epithelia]]), [[connective tissue]], [[nerve tissue]] and [[muscle tissue]].{{sfn|Gray's Anatomy|2008|p=27}}


== See also ==
Cells that lie on surfaces exposed to the outside world or gastrointestinal tract ([[epithelia]]) or internal cavities ([[endothelium]]) come in numerous shapes and forms – from [[squamous epithelium|single layers of flat cells]], to cells with small beating hair-like [[cilia]] in the lungs, to column-like cells that line the [[stomach]]. Endothelial cells are cells that line internal cavities including blood vessels and glands. Lining cells regulate what can and can't pass through them, protect internal structures, and function as sensory surfaces.{{sfn|Gray's Anatomy|2008|p=27}}
* [[CGP Grey]]
* [[Vsauce]]
* [[Tom Scott (presenter)|Tom Scott]]
* [[Veritasium]]


===Organs===
== References ==
{{reflist}}
{{See also|List of organs of the human body}}
[[organ (biology)|Organs]], structured collections of [[Cell (biology)|cells]] with a specific function,<ref>{{Cite web |url=http://www.collinsdictionary.com/dictionary/english/organ |title=organ {{!}} Definition, meaning & more |publisher=[[Collins Dictionary]] |website=www.collinsdictionary.com |access-date=17 September 2016}}</ref> mostly sit within the body, with the exception of [[Human skin|skin]]. Examples include the [[heart]], [[lung]]s and [[liver]]. Many organs reside within [[human body cavities|cavities]] within the body. These cavities include the [[abdominopelvic cavity|abdomen]] (which contains the stomach, for example) and [[pleural cavity|pleura]], which contains the lungs.


==== Heart ====
== External links ==
* {{Official website}}
{{Main|Heart}}
* {{cite web |url= https://presse.funk.net/format/dinge-erklaert-kurzgesagt/ |title= Dinge Erklaert Kurzgesagt |language= de |trans-title= Brief Explanations of Things |date= Jan 22, 2018 |publisher= [[Funk (streaming service)|Funk]] }}
The heart is an organ located in the [[thoracic cavity]] between the [[lung]]s and slightly to the left. It is surrounded by the [[pericardium]] which holds it in place in the [[mediastinum]] and serves to protect it from blunt trauma, [[infection]] and help lubricate the movement of the heart via [[pericardial fluid]].<ref>{{Cite journal|last1=Jaworska-Wilczynska|first1=Maria|last2=Trzaskoma|first2=Pawel|last3=Szczepankiewicz|first3=Andrzej A.|last4=Hryniewiecki|first4=Tomasz|date=2016|title=Pericardium: structure and function in health and disease|journal=Folia Histochemica et Cytobiologica|volume=54|issue=3|pages=121–125|doi=10.5603/FHC.a2016.0014|issn=1897-5631|pmid=27654013|doi-access=free}}</ref> The heart works by [[Circulatory system|pumping blood around the body]] allowing [[oxygen]], [[nutrient]]s, [[Metabolic waste|waste]], [[hormone]]s and [[white blood cell]]s to be transported.
[[File:Diagram of the human heart (cropped).svg|left|thumb|207x207px|Diagram of the human heart]]
The heart is composed of [[Atrium (heart)|two atria]] and [[Ventricle (heart)|two ventricles]]. The primary purpose of the atria is to allow uninterrupted venous blood flow to the heart during [[Systole|ventricular systole]]. This allows enough blood to get into the ventricles during [[Systole|atrial systole]]. Consequently, the atria allow a [[cardiac output]] roughly 75% greater than would be possible without them.<ref>{{Cite book|url=https://books.google.com/books?id=A3OmTSgtOgwC|title=The Gross Physiology of the Cardiovascular System|date=1999|first=Robert M. |last=Anderson|edition=2nd |chapter=Chapter 1: Normal Physiology |page=11}}</ref> The purpose of the ventricles is to [[Pulmonary circulation|pump blood to the lungs]] through the right ventricle and to [[Circulatory system|the rest of the body]] through the left ventricle.<ref>{{Cite web|title=Ventricle {{!}} heart|url=https://www.britannica.com/science/ventricle-heart|access-date=2021-08-07|website=Encyclopedia Britannica|language=en}}</ref>


{{DEFAULTSORT:Kurzgesagt - In a Nutshell}}
The heart has an [[Electrical conduction system of the heart|electrical conduction system]] to control the contractions and relaxation of the muscle. It starts in the [[sinoatrial node]] traveling through the atria causing them to [[Atrial systole|pump blood into the ventricles]]. It then travels to the [[atrioventricular node]] which makes the signal slow down slightly allowing the ventricles to fill with blood before pumping it out and starting the cycle over again.<ref>{{Cite web|title=How the Heart Works {{!}} NHLBI, NIH|url=https://www.nhlbi.nih.gov/health-topics/how-heart-works|access-date=2021-08-07|website=www.nhlbi.nih.gov|at=Your Heart's Electrical System}}</ref>
[[Category:Education-related YouTube channels]]

[[Category:YouTube channels launched in 2013]]
[[Coronary artery disease]] is the [[List of causes of death by rate|leading cause of death worldwide]], making up 16% of all deaths.<ref>{{Cite web|title=The top 10 causes of death|url=https://www.who.int/news-room/fact-sheets/detail/the-top-10-causes-of-death|access-date=2021-08-07|website=www.who.int|language=en}}</ref> It is caused by the buildup of [[Atherosclerosis|plaque]] in the [[coronary arteries]] supplying the heart, eventually the arteries may become so narrow that [[Ischemia|not enough blood]] is able to reach the [[Cardiac muscle|myocardium]],<ref>{{Cite web|last=CDC|date=2021-07-19|title=Coronary Artery Disease {{!}} cdc.gov|url=https://www.cdc.gov/heartdisease/coronary_ad.htm|access-date=2021-08-07|website=Centers for Disease Control and Prevention|language=en-us}}</ref> a condition known as [[Myocardial infarction|myocardial infarction or heart attack]], this can cause [[heart failure]] or [[cardiac arrest]] and eventually death.<ref>{{Cite web|last=CDC|date=2021-01-11|title=Heart Attack Symptoms, Risk Factors, and Recovery {{!}} cdc.gov|url=https://www.cdc.gov/heartdisease/heart_attack.htm|access-date=2021-08-07|website=Centers for Disease Control and Prevention|language=en-us}}</ref> Risk factors for coronary artery disease include [[Obesity-associated morbidity|obesity]], [[Health effects of tobacco|smoking]], [[Hypercholesterolemia|high cholesterol]], [[Hypertension|high blood pressure]], [[Sedentary lifestyle|lack of exercise]] and [[diabetes]].<ref>{{Cite web|last=CDC|date=2019-12-09|title=Know Your Risk for Heart Disease {{!}} cdc.gov|url=https://www.cdc.gov/heartdisease/risk_factors.htm|access-date=2021-08-07|website=Centers for Disease Control and Prevention|language=en-us}}</ref> [[Heart cancer|Cancer can affect the heart]], though it is exceedingly rare and has usually [[Metastasis|metastasized]] from another part of the body such as the [[Lung cancer|lungs]] or [[Breast cancer|breasts]]. This is because the [[Cardiac muscle|heart cells]] quickly stop dividing and all growth occurs through [[Hypertrophy|size increase]] rather than [[Mitosis|cell division]].<ref>{{Cite web|date=2009-02-10|title=Matters of the Heart: Why Are Cardiac Tumors So Rare? |url=https://www.cancer.gov/types/metastatic-cancer/research/cardiac-tumors|access-date=2021-08-07|website=www.cancer.gov – National Cancer Institute|language=en}}</ref>
[[Category:German YouTubers]]

[[Category:Science-related YouTube channels]]
==== Gallbladder ====
[[Category:Patreon creators]]
{{Main|Gallbladder}}
[[Category:English-language YouTube channels]]
The gallbladder is a hollow pear shaped organ located [[Posterior (anatomy)|posterior]] to the [[Inferior (anatomy)|inferior]] middle part of the [[Lobes of liver|right lobe of the liver]]. It is variable in shape and size. It stores [[bile]] before it is released into the small intestine via the [[common bile duct]] to help with [[Lipid metabolism|digestion of fats]]. It receives bile from the [[liver]] via the [[cystic duct]] which connects to the [[common hepatic duct]] to form the [[common bile duct]].<ref name="Nagral2005">{{cite journal|last1=Nagral|first1=Sanjay|title=Anatomy relevant to cholecystectomy|journal=Journal of Minimal Access Surgery|date=2005|volume=1|issue=2|pages=53–8|doi=10.4103/0972-9941.16527|pmid=21206646|pmc=3004105}}</ref>
[[Category:Educational and science YouTubers]]

The gallbladder gets its blood supply from the [[cystic artery]] which in most people emerges from the [[Hepatic artery proper|right hepatic artery]].<ref name="Nagral2005" />

[[Gallstone]]s is a common disease in which one or more stones form in the gallbladder or [[biliary tract]]. Most people are asymptomatic but if a stone blocks the biliary tract it causes a [[Biliary colic|gallbladder attack]], symptoms may include sudden pain in the upper right abdomen and or center of the abdomen. Nausea and vomiting may also occur. Typical treatment is removal of the gallbladder through a procedure called a [[cholecystectomy]].<ref>{{Cite web|title=Gallstones – Symptoms and causes|url=https://www.mayoclinic.org/diseases-conditions/gallstones/symptoms-causes/syc-20354214|access-date=2021-08-07|website=Mayo Clinic|language=en}}</ref><ref>{{Cite web|title=Gallstones – Diagnosis and treatment |url=https://www.mayoclinic.org/diseases-conditions/gallstones/diagnosis-treatment/drc-20354220|access-date=2021-08-07|website=www.mayoclinic.org}}</ref> Having gallstones is a risk factor for [[gallbladder cancer]] which although quite uncommon is rapidly fatal if not diagnosed early.<ref>{{Cite web|title=Gallbladder cancer – Symptoms and causes|url=https://www.mayoclinic.org/diseases-conditions/gallbladder-cancer/symptoms-causes/syc-20353370|access-date=2021-08-07|website=Mayo Clinic|language=en}}</ref>

===Systems===
{{See also|List of systems of the human body}}
<!--
<gallery mode=packed heights=350px>
File:Organ Systems I.jpg
File:Organ Systems II.jpg
</gallery>-->

====Circulatory system====
{{Main|Circulatory system}}

The [[circulatory system]] consists of the [[heart]] and [[blood vessel]]s ([[artery|arteries]], [[vein]]s and [[capillary|capillaries]]). The heart propels the circulation of the blood, which serves as a "transportation system" to transfer [[oxygen]], fuel, nutrients, waste products, immune cells and signalling molecules (i.e. [[hormones]]) from one part of the body to another. Paths of blood circulation within the human body can be divided into two circuits: the [[Pulmonary circulation|pulmonary circuit]], which pumps blood to the lungs to receive [[oxygen]] and leave [[carbon dioxide]], and the systemic circuit, which carries blood from the heart off to the rest of the body. The blood consists of fluid that carries [[Cell (biology)|cells]] in the circulation, including some that move from tissue to blood vessels and back, as well as the [[spleen]] and [[bone marrow]].<ref>{{Cite news|title=Cardiovascular System|publisher=[[U.S. National Cancer Institute]]|url=http://training.seer.cancer.gov/module_anatomy/unit7_1_cardvasc_intro.html|url-status=dead|access-date=16 September 2008|archive-url=https://web.archive.org/web/20070202040248/http://www.training.seer.cancer.gov/module_anatomy/unit7_1_cardvasc_intro.html|archive-date=2 February 2007}}</ref><ref>{{Cite book |url=https://archive.org/details/humanbiologyheal00scho |title=Human Biology and Health |publisher=[[Pearson Prentice Hall]] |year=1993 |isbn=0-13-981176-1 |location=Upper Saddle River, NJ}}</ref><ref>{{Cite web |url=http://ect.downstate.edu/courseware/histomanual/cardiovascular.html |title=The Cardiovascular System |date=8 March 2008 |publisher=[[State University of New York]] Downstate Medical Center}}</ref><ref>{{cite journal |url=https://www.khanacademy.org/science/high-school-biology/hs-human-body-systems/hs-the-circulatory-and-respiratory-systems/a/hs-the-circulatory-system-review |title=The Circulatory and Respiratory Systems |journal=[[The Circulatory System Review"]] |publisher=Khan Academy |access-date=29 June 2019}}</ref>

====Digestive system====
{{Main|Digestive system}}
[[File:Digestive system diagram en.svg|left|thumb|Digestive system]]
The [[digestive system]] consists of the mouth including the [[tongue]] and [[teeth (human)|teeth]], [[esophagus]], [[stomach]], ([[human gastrointestinal tract|gastrointestinal tract]], [[small intestine|small]] and [[large intestine]]s, and [[rectum]]), as well as the [[liver]], [[pancreas]], [[gallbladder]], and [[salivary gland]]s. It converts food into small, nutritional, non-toxic [[molecule]]s for distribution and absorption into the body. These molecules take the form of [[protein]]s (which are broken down into [[amino acid]]s), [[fat]]s, [[vitamin]]s and [[mineral]]s (the last of which are mainly ionic rather than molecular). After being [[Swallowing|swallowed]], food moves through the [[gastrointestinal tract]] by means of [[peristalsis]]: the systematic expansion and contraction of muscles to push food from one area to the next.<ref>{{Cite web |url=https://www.niddk.nih.gov/health-information/health-topics/Anatomy/your-digestive-system/Pages/anatomy.aspx |title=Your Digestive System and How It Works |publisher=[[National Institute of Health]] |access-date=4 September 2016}}</ref><ref name="niddk.nih.gov">{{cite web |url=https://www.niddk.nih.gov/health-information/digestive-diseases/digestive-system-how-it-works |title=Your Digestive System & How it Works |publisher=[[National Institute of Diabetes and Digestive and Kidney Diseases]] |access-date=29 June 2019}}</ref>

Digestion begins in the [[mouth]], which [[Chewing|chews]] food into smaller pieces for easier digestion. Then it is [[Swallowing|swallowed]], and moves through the [[esophagus]] to the [[stomach]]. In the stomach, food is mixed with [[gastric acid]]s to allow the extraction of [[nutrient]]s. What is left is called [[chyme]]; this then moves into the [[small intestine]], which absorbs the nutrients and water from the chyme. What remains passes on to the [[large intestine]], where it is dried to form [[feces]]; these are then stored in the [[rectum]] until they are expelled through the [[anus]].<ref name="niddk.nih.gov" />

====Endocrine system====
{{Main|Endocrine system}}

The [[endocrine system]] consists of the principal [[endocrine gland]]s: the [[pituitary]], [[thyroid]], [[adrenal]]s, [[pancreas]], [[parathyroid]]s, and [[gonad]]s, but nearly all organs and tissues produce specific endocrine [[hormone]]s as well. The endocrine hormones serve as signals from one body system to another regarding an enormous array of conditions, and resulting in variety of changes of function.<ref>{{cite web|title=Hormonal (endocrine) system|url=https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/hormonal-endocrine-system |publisher=[[Victoria State Government]]|access-date=4 September 2016}}</ref>

====Immune system====
{{Main|Immune system}}

The [[immune system]] consists of the [[white blood cell]]s, the [[thymus]], [[lymph node]]s and [[lymph]] channels, which are also part of the [[lymphatic system]]. The immune system provides a mechanism for the body to distinguish its own cells and tissues from outside cells and substances and to neutralize or destroy the latter by using specialized proteins such as [[antibodies]], [[cytokines]], and [[toll-like receptors]], among many others.<ref>{{cite web|last1=Zimmermann|first1=Kim Ann|title=Immune System: Diseases, Disorders & Function|url=http://www.livescience.com/26579-immune-system.html|publisher=[[LiveScience]]|access-date=4 September 2016}}</ref>
[[File:Skin layers.svg|thumb|236x236px|Skin]]

====Integumentary system====
{{Main|Integumentary system}}

The [[integumentary system]] consists of the covering of the body (the skin), including hair and [[nail (anatomy)|nails]] as well as other functionally important structures such as the [[sweat gland]]s and [[sebaceous gland]]s. The skin provides containment, structure, and protection for other organs, and serves as a major sensory interface with the outside world.<ref>{{MeSH name|Integumentary+System}}</ref><ref>{{cite book | last1=Marieb | first1=Elaine |author-link=Elaine Nicpon Marieb |last2=Hoehn |first2=Katja | title=Human Anatomy & Physiology | url=https://archive.org/details/humananatomyphys00mari_4 | url-access=registration | publisher=[[Pearson Benjamin Cummings]] | year=2007 | edition=7th | page=[https://archive.org/details/humananatomyphys00mari_4/page/142 142]| isbn=978-0805359107 }}</ref>

====Lymphatic system====
{{Main|Lymphatic system}}

The [[lymphatic system]] extracts, transports and metabolizes lymph, the fluid found in between cells. The lymphatic system is similar to the circulatory system in terms of both its structure and its most basic function, to carry a body fluid.<ref>{{cite web|last1=Zimmermann|first1=Kim Anne|title=Lymphatic System: Facts, Functions & Diseases|url=http://www.livescience.com/26983-lymphatic-system.html|publisher=LiveScience|access-date=4 September 2016}}</ref>

====Musculoskeletal system====
{{Main|Musculoskeletal system}}

The [[musculoskeletal system]] consists of the [[human skeleton]] (which includes [[bone]]s, [[ligament]]s, [[tendon]]s, [[joints]] and [[cartilage]]) and attached [[muscle]]s. It gives the body basic structure and the ability for movement. In addition to their structural role, the larger bones in the body contain [[bone marrow]], the site of production of blood cells. Also, all bones are major storage sites for [[Calcium in biology|calcium]] and [[phosphate]]. This system can be split up into the [[muscular system]] and the [[skeletal system]].<ref>{{cite book | title=Moore's Clinically Oriented Anatomy | publisher=[[Lippincott Williams & Wilkins]] | last1=Moore |first1=Keith L. |last2=Dalley |first2=Arthur F. |last3=Agur |first3=Anne M. R. | year=2010 | location=Phildadelphia | pages=2–3 | isbn=978-1-60547-652-0}}</ref>

====Nervous system====
{{Main|Nervous system}}
[[File:Nervous system diagram.png|thumb|303x303px|Nervous system]]

The [[nervous system]] consists of the body's [[neuron]]s and [[glia]]l cells, which together form the [[nerves]], [[ganglia]] and [[gray matter]] which in turn form the [[brain]] and related structures. The brain is the organ of [[thought]], emotion, [[memory]], and [[sensory processing]]; it serves many aspects of communication and controls various systems and functions. The [[special senses]] consist of [[Visual perception|vision]], [[Hearing (sense)|hearing]], [[taste]], and [[olfaction|smell]]. The [[human eye|eyes]], [[ear]]s, [[tongue]], and nose gather information about the body's environment.<ref>{{cite encyclopedia |last1=Lagassé |first1=Paul |location=New York Detroit | title=Nervous System | encyclopedia=Columbia Encyclopedia | publisher=[[Columbia University Press]] Sold and distributed by [[Gale Group]] | edition=6th | date=2001 | isbn=978-0-7876-5015-5 | url=https://archive.org/details/columbiaencyclop00laga }}</ref>

From a structural perspective, the [[nervous system]] is typically subdivided into two component parts: the [[central nervous system]] (CNS), composed of the brain and the [[spinal cord]]; and the [[peripheral nervous system]] (PNS), composed of the nerves and [[ganglion|ganglia]] outside the brain and spinal cord. The CNS is mostly responsible for organizing [[motion]], processing [[Sense|sensory information]], thought, memory, [[cognition]] and other such functions.<ref name="livescience.com">{{Cite web|first1=James |last1=Horton |first2=Alina |last2=Bradford |first3=Kim Ann |last3=Zimmermann|date=2022-03-25|title=Nervous System: Facts, Function & Diseases|url=https://www.livescience.com/22665-nervous-system.html|access-date=2023-02-08|website=livescience.com|language=en}}</ref> It remains a matter of some debate whether the [[central nervous system|CNS]] directly gives rise to [[consciousness]].{{cn|date=May 2023}} The [[peripheral nervous system]] (PNS) is mostly responsible for gathering information with [[sensory neuron]]s and directing body movements with [[motor neuron]]s.<ref name="livescience.com"/>

From a functional perspective, the nervous system is again typically divided into two component parts: the [[somatic nervous system]] (SNS) and the [[autonomic nervous system]] (ANS). The SNS is involved in voluntary functions like [[speech|speaking]] and [[sense|sensory processes]]. The ANS is involved in involuntary processes, such as [[digestion]] and regulating [[blood pressure]].<ref>{{Cite web|title=Visual Guide to Your Nervous System|url=https://www.webmd.com/brain/ss/slideshow-nervous-system-overview|access-date=2023-02-08|website=WebMD|language=en}}</ref>

The nervous system is subject to many different diseases. In [[epilepsy]], abnormal electrical activity in the brain can cause [[epileptic seizure|seizures]]. In [[multiple sclerosis]], the [[immune system]] attacks the [[myelin|nerve linings]], damaging the nerves' ability to transmit signals. [[Amyotrophic lateral sclerosis]] (ALS), also known as [[Lou Gehrig]]'s disease, is a [[motor neuron]] disease which gradually reduces movement in patients. There are also many other diseases of the nervous system.<ref name="livescience.com"/><!--and Female?-->

====Reproductive system====
{{Main|Human reproductive system}}

The primary purpose of the reproductive system is to produce new humans in the form of [[child]]ren and ensure their [[Puberty|sexual development]] so that they can produce new humans too. It is composed of the [[gonad]]s ([[Testicle|testes]] and [[Ovary|ovaries]]) which produce [[Egg cell|eggs]] and [[Spermatozoon|sperm cells]] ([[gamete]]s) and produce [[Sex hormone|hormones]] necessary for proper [[Puberty|sexual development]]. The rest of the [[gland]]s and ducts of the reproductive system are responsible for the transportation and sustaining of the [[gamete]]s and to [[Pregnancy|nurture the offspring]].<ref>{{cite web|title=Introduction to the Reproductive System|url=http://training.seer.cancer.gov/module_anatomy/unit12_1_repdt_intro.html|publisher=Epidemiology and End Results (SEER) Program|url-status=dead|archive-url=https://web.archive.org/web/20070102181148/http://training.seer.cancer.gov/module_anatomy/unit12_1_repdt_intro.html|archive-date=2 January 2007}}</ref>

The reproductive system is first stimulated by the [[hypothalamus]] during [[puberty]] which causes the [[Ovary|ovaries]] and [[Testicle|testes]] to produce [[testosterone]] (male) and [[estrogen]] and [[progesterone]] (female). Male puberty generally occurs between the ages of 13-15 and is characterized by beginning of [[Spermatogenesis|sperm production]] and the development of [[secondary sex characteristic]]s such as increased height and weight, broadened shoulders, [[Pubic hair|pubic]] and [[facial hair]], voice deepening and muscle development. Female puberty generally occurs between the ages of 9-13 and is characterized by [[ovulation]] and [[menstruation]]. The growth of secondary sex characteristics such as growth of [[Pubic hair|pubic]] and [[underarm hair]], [[breast]], [[Uterus|uterine]] and [[vagina]]l growth, widening hips and increased height and weight also occur during the female puberty process.<ref name=":0">{{Cite web|title=Technical Issues In Reproductive Health|url=http://www.columbia.edu/itc/hs/pubhealth/modules/reproductiveHealth/anatomy.html|access-date=2021-08-07|website=www.columbia.edu}}</ref>
[[File:Human male reproductive system en.svg|left|thumb|360x360px|Internal [[gross anatomy]] of the [[male reproductive system]]]]
The external [[male reproductive system]] is made up of the [[penis]] and the [[scrotum]] which is a bag that protects the [[testis]]. The penis consists of the [[Glans penis|glans]] which is the head of the penis and contains the [[urethra]] and [[urinary meatus]] the point where urine exits the penis, the rest of the penis is called the [[Corpus cavernosum penis|shaft or corpus cavernosum]] and contains most of the [[urethra]]. The glans is covered by a fold of skin called the [[foreskin]] though this can be removed through [[circumcision]].<ref name=":0" />
[[File:Mons-pubis-anatomical-location-in-female-reproductive-system.png|thumb|External female reproductive system with mons pubis highlighted]]
Internally the male reproductive system starts in the testes where hundreds of [[seminiferous tubule]]s produce [[sperm]] which is then stored and matured into [[spermatozoon]] in the [[epididymis]]. They are then brought through the [[vas deferens]] which leads away from the testes to the [[seminal vesicles]] where the sperm cells are mixed with a [[fructose]]-rich fluid from the seminal vesicles allowing the sperm to stay alive and remain healthy. It is then brought by the [[ejaculatory duct]] through the [[prostate]] and [[bulbourethral gland]], and mixed with fluids from said glands. The [[Prostatic fluid|fluid from the prostate]] helps to neutralize the acidity of the vagina and keep the sperm alive. This mixture of sperm and accessory gland fluids is called [[semen]] and is released through the [[urethra]] during [[ejaculation]]. Almost the entire internal male reproductive system works in pairs with two [[Testicle|testes]], two [[epididymis]], two [[vas deferens]], two [[seminal vesicles]], two [[ejaculatory duct]]s, two [[bulbourethral gland]]s, but only one [[prostate]] and [[urethra]].<ref name=":0" /><ref>{{Cite web|title=Accessory Glands {{!}} SEER Training|url=https://www.training.seer.cancer.gov/anatomy/reproductive/male/glands.html|access-date=2021-08-07|website=www.training.seer.cancer.gov}}</ref>

The external [[female reproductive system]] also called the [[vulva]] consists of the [[mons pubis]] a fatty mass that covers the [[Pubis (bone)|pubis]], the [[labia majora]] (outer lips of the vagina), the [[labia minora]] (inner lips of the vagina), the [[Vagina|vaginal opening]] which opens into vagina and is where the penis is inserted during [[sexual intercourse]] and [[Childbirth|children are born]], the urethral opening which is the opening for the [[urethra]] that carries [[urine]] from the [[Urinary bladder|bladder]] and the [[clitoris]] which contains the most sensitive nerve endings and in humans has no use other than [[Sexual stimulation|sexual pleasure]]. Located between the anus and vagina is the [[perineum]].<ref>{{Cite web|title=External Genitalia {{!}} SEER Training|url=https://www.training.seer.cancer.gov/anatomy/reproductive/female/genitalia.html|access-date=2021-08-07|website=www.training.seer.cancer.gov}}</ref><ref name=":0" />
[[File:Scheme female reproductive system-en.svg|thumb|Internal [[gross anatomy]] of the [[female reproductive system]]]]
Internally the female reproductive system contains two [[Ovary|ovaries]], the [[uterus]], two [[fallopian tube]]s and the [[cervix]]. At birth a female has about 700,000 [[oocyte]]s (the immature version of the egg cell) in both ovaries combined, though this degenerates to about 400,000 by the time [[puberty]] is reached. This is a lifetime supply as after birth no more [[oocyte]]s are produced, compared to males where [[Spermatozoon|sperm cells]] are produced during their entire lifetime. During puberty the [[menstrual cycle]] begins for the first time, in response to low [[estrogen]] and [[progesterone]] levels the [[hypothalamus]] releases [[Gonadotropin-releasing hormone|gonadotropin releasing hormone]] (GnRH). This causes the [[Anterior pituitary|anterior pituitary gland]] to release [[follicle-stimulating hormone]] (FSH) and [[luteinizing hormone]] (LH). FSH stimulates [[ovarian follicle]]s to grow and one dominant follicle will eventually take over. As it continues to grow it releases more and more [[estradiol]] which stimulates LH secretion and suppresses FSH secretion preventing further follicular growth. When [[Luteinizing hormone|LH levels are highest]] the follicle ruptures releasing the [[Egg cell|ovum]] in a process called [[ovulation]] where it is then moved to one of the [[fallopian tube]]s. After ovulation the portion of the follicle that remains in the ovary is transformed into [[corpus luteum]] which continues to produce estrogen and high levels of progesterone. The [[progesterone]] causes the [[endometrium]] to grow thick preparing it for implantation of a [[Zygote|fertilized egg]]. If fertilization occurs the [[corpus luteum]] continues to secrete hormones until the [[placenta]] develops enough to secrete the necessary hormones for maintaining [[pregnancy]]. Eventually the [[corpus luteum]] will turn into [[corpus albicans]] which is essentially scar tissue. If fertilization fails the [[corpus luteum]] will degrade into [[corpus albicans]] and stop secreting enough [[progesterone]] and [[estrogen]] causing the [[Endometrium|endometrial lining]] to break resulting in [[menstruation]].<ref name=":0" /><ref>{{Cite web|title=Ovaries {{!}} SEER Training|url=https://www.training.seer.cancer.gov/anatomy/reproductive/female/ovaries.html|access-date=2021-08-07|website=www.training.seer.cancer.gov}}</ref>

Many diseases affect the reproductive system such as [[polycystic ovary syndrome]] (PCOS) which is characterized by [[Hyperandrogenism|elevated androgen levels]], [[Irregular menstruation|menstrual irregularities]] and/or small [[Ovarian cyst|cysts]] on one or both of the ovaries. It is a common disease affecting at least 7% of adult women. Symptoms include excess body hair, [[infertility]], [[weight gain]], [[Pattern hair loss|male pattern baldness]] and [[irregular menstruation]].<ref>{{Cite journal|last1=Ndefo|first1=Uche Anadu|last2=Eaton|first2=Angie|last3=Green|first3=Monica Robinson|date=June 2013|title=Polycystic Ovary Syndrome|journal=Pharmacy and Therapeutics|volume=38|issue=6|pages=336–355|issn=1052-1372|pmc=3737989|pmid=23946629}}</ref><ref>{{Cite web|title=Polycystic Ovary Syndrome (PCOS)|url=https://www.hopkinsmedicine.org/health/conditions-and-diseases/polycystic-ovary-syndrome-pcos|access-date=2021-08-07|website=www.hopkinsmedicine.org|language=en}}</ref>

Another reproductive disease is [[testicular torsion]], it occurs when the [[spermatic cord]] which holds up the testicle wraps around itself cutting off [[Ischemia|blood flow to the testicle]]. [[Testicular torsion]] is a [[medical emergency]] and can result in testicular death or [[infertility]] if not treated immediately by physically unwrapping the [[spermatic cord]]. If the testicle has suffered [[Infarction|severe damage]], it may need to be surgically in a lateral [[orchiectomy]]. The primary symptom of testicular torsion is severe [[testicular pain]] at rest, nausea and vomiting may also occur. Testicular torsion can occur at any age though it is most common in 12-18 year olds.<ref>{{Cite journal|last=Hyun|first=Grace S.|date=2018|title=Testicular Torsion|journal=Reviews in Urology|volume=20|issue=2|pages=104–106|doi=10.3909/riu0800|doi-broken-date=31 December 2022|issn=1523-6161|pmc=6168322|pmid=30288149}}</ref><ref>{{Cite journal|last1=Ringdahl|first1=Erika|last2=Teague|first2=Lynn|date=2006-11-15|title=Testicular torsion|url=https://pubmed.ncbi.nlm.nih.gov/17137004/|journal=American Family Physician|volume=74|issue=10|pages=1739–1743|issn=0002-838X|pmid=17137004}}</ref>

[[Sexually transmitted infection]]s such as [[syphilis]], [[HIV]], [[chlamydia]], [[Human papillomavirus infection|HPV]] and [[genital wart]]s are spread through [[sexual intercourse]] including [[Oral sex|oral]], vaginal and [[anal sex]]. Many of these infections can be lethal if left untreated though others are mostly [[Benignity|harmless]].<ref>{{Cite web|date=2021-08-02|title=Sexually Transmitted Diseases – Information from CDC|url=https://www.cdc.gov/std/default.htm|access-date=2021-08-07|website=www.cdc.gov|language=en-us}}</ref><ref>{{Cite web|date=2021-06-23|title=CDC – STDs – HPV|url=https://www.cdc.gov/std/hpv/default.htm|access-date=2021-08-07|website=www.cdc.gov|language=en-us}}</ref>

Cancer can affect many parts of the reproductive system including [[Penile cancer|the penis]], [[Testicular cancer|testicles]], [[Prostate cancer|prostate]], [[Ovarian cancer|ovaries]], [[Cervical cancer|cervix]], [[Vaginal cancer|vagina]], [[Fallopian tube cancer|fallopian]], [[Uterine cancer|uterus]] and [[Vulvar cancer|vulva]].<ref>{{Cite web|title=Reproductive Cancers {{!}} HHS Office of Population Affairs|url=https://opa.hhs.gov/reproductive-health/reproductive-cancers|access-date=2021-08-07|website=opa.hhs.gov|language=en}}</ref>

==== Respiratory system ====
{{Main|Respiratory system}}

The [[respiratory system]] consists of the nose, [[nasopharynx]], [[Vertebrate trachea|trachea]], and [[lungs]]. It brings oxygen from the air and excretes [[carbon dioxide]] and water back into the air. First, [[Atmosphere of Earth|air]] is pulled through the trachea into the lungs by the [[thoracic diaphragm|diaphragm]] pushing down, which creates a [[vacuum]]. Air is briefly stored inside small sacs known as [[Pulmonary alveolus|alveoli]] (sing.: alveolus) before being expelled from the lungs when the diaphragm contracts again. Each alveolus is surrounded by [[Capillary|capillaries]] carrying deoxygenated blood, which absorbs oxygen out of the air and into the [[bloodstream]].<ref>{{cite book |last1=Maton |first1=Anthea|first2=Jean |last2= Hopkins |first3=Susan |last3=Johnson|first4=Charles William |last4= McLaughlin |first5=Maryanna Quon |last5=Warner |first6=David |last6= LaHart |first7=Jill D. |last7=Wright |title=Human Biology and Health |publisher=[[Prentice Hall]] |year=2010 |pages=108–118 |isbn=978-0-13-423435-9}}</ref><ref name="webmd.com">{{Cite web|title=Respiratory System|url=https://www.webmd.com/lung/how-we-breathe|access-date=2023-02-08|website=WebMD|language=en}}</ref>

For the respiratory system to function properly, there need to be as few impediments as possible to the movement of air within the lungs. [[Inflammation]] of the lungs and excess [[mucus]] are common sources of breathing difficulties.<ref name="webmd.com"/> In [[asthma]], the respiratory system is persistently inflamed, causing [[Wheeze|wheezing]] and/or [[shortness of breath]]. [[Pneumonia]] occurs through [[infection]] of the alveoli, and may be caused by [[tuberculosis]]. [[Chronic obstructive pulmonary disease|Emphysema]], commonly a result of [[smoking]], is caused by damage to connections between the alveoli.<ref>{{Cite web|last=Hoffman|first=Matthew|title=Lung Diseases Overview|url=https://www.webmd.com/lung/lung-diseases-overview|access-date=2023-02-08|website=WebMD|language=en}}</ref>

====Urinary system====
{{Main|Urinary system}}
[[File:Urinary System (Female).png|left|thumb|Female urinary system]]
The [[urinary system]] consists of the two [[kidney]]s, two [[ureter]]s, [[Urinary bladder|bladder]], and [[urethra]]. It removes<!--excretion--> waste materials from the blood through urine, which carries a variety of waste molecules and excess [[ion]]s and water out of the body.

First, the [[kidney]]s filter the blood through their respective [[nephron]]s, removing [[Metabolic waste|waste products]] like [[urea]], [[creatinine]] and maintaining the [[Electrolyte imbalance|proper balance]] of [[electrolyte]]s and turning the waste products into [[urine]] by combining them with water from the blood.<ref>{{Cite web|title=The Kidneys – a Basic Guide|url=https://www.nhs.uk/Livewell/Kidneyhealth/Documents/kidney%20guide.pdf|url-status=live|archive-url=https://web.archive.org/web/20210109023755/https://www.nhs.uk/Livewell/Kidneyhealth/Documents/kidney%20guide.pdf|archive-date=January 9, 2021|access-date=August 7, 2021|website=[[National Health Service]]}}</ref> The kidneys filter about 150 quarts (170 liters) of blood daily, but most of it is returned to the blood stream with only 1-2 quarts (1-2 liters) ending up as urine.<ref>{{Cite web|title=Your Kidneys & How They Work {{!}} NIDDK|url=https://www.niddk.nih.gov/health-information/kidney-disease/kidneys-how-they-work|access-date=2021-08-07|website=National Institute of Diabetes and Digestive and Kidney Diseases|language=en-US}}</ref> The urine is brought by the [[ureter]]s from the kidneys down to the [[Urinary bladder|bladder]].

The [[smooth muscle]] lining the ureter walls continuously tighten and relax through a process called [[peristalsis]] to force urine away from the kidneys and down into the bladder. Small amounts of urine are released into the bladder every 10–15 seconds.

The bladder is a hollow balloon shaped organ located in the [[pelvis]]. It stores urine until the brain signals it to relax the [[Urethral sphincters|urinary sphincter]] and release the urine into the urethra starting [[urination]].<ref>{{Cite web|title=The Urinary Tract & How It Works {{!}} NIDDK|url=https://www.niddk.nih.gov/health-information/urologic-diseases/urinary-tract-how-it-works|access-date=2021-08-07|website=National Institute of Diabetes and Digestive and Kidney Diseases|language=en-US}}</ref> A normal bladder can hold up to 16 ounces (half a liter) for 3–5 hours comfortably.

Numerous [[Urologic disease|diseases affect the urinary system]] including [[Kidney stone disease|kidney stones]] which are formed when materials in the urine concentrate enough to form a solid mass, [[urinary tract infection]]s which are infections of the urinary tract and can cause pain when urinating, frequent urination and even death if left untreated. [[Kidney failure|Renal failure]] occurs when the kidneys fail to adequately filter waste from the blood and can lead to death if not treated with [[Kidney dialysis|dialysis]] or [[kidney transplantation]].<ref>{{cite web |last1=Zimmermann |first1=Kim Ann |title=Urinary System: Facts, Functions & Diseases |url=http://www.livescience.com/27012-urinary-system.html |publisher=LiveScience |access-date=4 September 2016}}</ref> [[Cancer]] can affect the [[Bladder cancer|bladder]], [[Kidney cancer|kidneys]], [[Urethral cancer|urethra]] and [[Ureteral cancer|ureters]] with the latter two being far more rare.<ref>{{Cite journal|last=Yaxley|first=Julian P.|date=2016|title=Urinary tract cancers: An overview for general practice|journal=Journal of Family Medicine and Primary Care|volume=5|issue=3|pages=533–538|doi=10.4103/2249-4863.197258|issn=2249-4863|pmc=5290755|pmid=28217578}}</ref>

==Anatomy==
{{Main|Outline of human anatomy|Anatomy}}
[[File:Body cavities.jpg|thumb|left|upright=1.35|[[Body cavity|Cavities]] of human body]]

Human [[anatomy]] is the study of the shape and form of the human body. The human body has four [[limb (anatomy)|limbs]] (two arms and two legs), a head and a [[neck]] which connect to the [[torso]]. The body's shape is determined by a strong [[human skeleton|skeleton]] made of [[bone]] and [[cartilage]], surrounded by fat ([[adipose tissue]]), muscle, [[connective tissue]], organs, and other structures. The [[Vertebral column|spine]] at the back of the skeleton contains the flexible [[vertebral column]] which surrounds the [[spinal cord]], which is a collection of nerve fibres connecting the [[brain]] to the rest of the body. [[Nerve]]s connect the spinal cord and brain to the rest of the body. All major bones, muscles, and nerves in the body are named, with the exception of [[anatomical variation]]s such as [[sesamoid bone]]s and [[accessory muscle]]s.

Blood vessels carry blood throughout the body, which moves because of the beating of the [[heart]]. [[Venule]]s and [[vein]]s collect blood low in oxygen from tissues throughout the body. These collect in progressively larger veins until they reach the body's two largest veins, the [[superior vena cava|superior]] and [[inferior vena cava]], which drain blood into the right side of the heart. From here, the blood is pumped into the [[lung]]s where it receives oxygen and drains back into the left side of the heart. From here, it is pumped into the body's largest [[artery]], the [[aorta]], and then progressively smaller arteries and [[arteriole]]s until it reaches tissue. Here blood passes from small arteries into [[capillaries]], then small veins and the process begins again. Blood carries [[oxygen]], waste products, and [[hormone]]s from one place in the body to another. Blood is filtered at the [[kidney]]s and [[liver]].

The body consists of a number of [[body cavity|body cavities]], separated areas which house different organ systems. The brain and [[central nervous system]] reside in an area protected from the rest of the body by the [[blood brain barrier]]. The lungs sit in the [[pleural cavity]]. The [[intestine]]s, [[liver]], and [[spleen]] sit in the [[abdominal cavity]].

Height, weight, [[Body shape|shape]] and other [[body proportions]] vary individually and with age and sex. Body shape is influenced by the distribution of bones, [[muscle]] and [[fat tissue]].<ref name="bartleby1918">{{cite web|url=http://www.bartleby.com/107/|title=Anatomy of the Human Body|date=1918|publisher=Bartleby|last1=Gray|first1=Henry|author-link1=Henry Gray|access-date=4 September 2016}}</ref>

==Physiology==
{{Main|Outline of physiology|Physiology}}

Human [[physiology]] is the study of how the human body functions. This includes the mechanical, physical, [[Bioelectromagnetism|bioelectrical]], and [[Biochemistry|biochemical]] functions of humans in good health, from [[organ (biology)|organs]] to the [[Cell (biology)|cells]] of which they are composed. The human body consists of many interacting systems of organs. These interact to maintain [[homeostasis]], keeping the body in a stable state with safe levels of substances such as sugar and oxygen in the blood.<ref name=UL>{{cite web |title=What is Physiology? |url=http://www.understanding-life.org/what-physiology |publisher=Understanding Life |access-date=4 September 2016 |archive-url=https://web.archive.org/web/20170819102127/http://www.understanding-life.org/what-physiology |archive-date=19 August 2017 |url-status=dead }}</ref>

Each system contributes to homeostasis, of itself, other systems, and the entire body. Some combined systems are referred to by joint names. For example, the nervous system and the endocrine system operate together as the [[neuroendocrine system]]. The nervous system receives information from the body, and transmits this to the brain via [[nerve impulse]]s and [[neurotransmitter]]s. At the same time, the [[endocrine system]] releases hormones, such as to help regulate [[blood pressure]] and volume. Together, these systems regulate the internal environment of the body, maintaining blood flow, posture, energy supply, temperature, and acid balance ([[pH]]).<ref name=UL/>

==Development==
{{Main|Development of the human body}}
[[File:Little baby from Puno.jpg|thumb|Baby being carried]]

Development of the human body is the process of growth to maturity. The process begins with fertilisation, where an egg released from the [[ovary]] of a female is penetrated by [[sperm]]. The egg then lodges in the [[uterus]], where an [[embryo]] and later [[fetus]] develop until [[childbirth|birth]]. Growth and development occur after birth, and include both physical and psychological development, influenced by genetic, hormonal, environmental and other factors. Development and growth continue throughout life, through [[childhood]], [[adolescence]], and through [[adulthood]] to [[old age]], and are referred to as the process of [[aging]].

==Society and culture==
===Professional study===
{{Further|History of anatomy|History of medicine|History of physiology}}
[[File:Anatomical Male Figure Showing Heart, Lungs, and Main Arteries.jpg|thumb|left|upright|Anatomical study by [[Leonardo da Vinci]] ]]

[[Health professional]]s learn about the human body from illustrations, models, and demonstrations. Medical and dental students in addition gain practical experience, for example by [[dissection]] of cadavers. Human anatomy, [[physiology]], and [[biochemistry]] are basic medical sciences, generally taught to medical students in their first year at medical school.<ref name=introHGray>{{cite web | url=http://www.bartleby.com/107/1.html| title= Introduction page, "Anatomy of the Human Body". Henry Gray|orig-year=1918| access-date =27 March 2007}}</ref><ref name="Gray">{{cite book |url=https://archive.org/details/graysanatomyanat0000unse |title=Publisher's page for Gray's Anatomy|edition= 39th |year=2004 |isbn=0-443-07168-3 |access-date=27 March 2007 |url-access=registration |last1=Drake |first1=Richard Lee |last2=Gray |first2=Henry |last3=Vogl |first3=Wayne |last4=Mitchell |first4=Adam W. M. }}</ref><ref>{{cite book |url= http://www.us.elsevierhealth.com/product.jsp?isbn=0443071683 | title=Publisher's page for Gray's Anatomy |edition=39th (US) |year=2004 |isbn=0-443-07168-3| access-date=27 March 2007 |archive-url=https://web.archive.org/web/20070209134753/http://www.us.elsevierhealth.com/product.jsp?isbn=0443071683 |archive-date=9 February 2007| last1=Drake | first1=Richard Lee | last2=Gray | first2=Henry | last3=Vogl | first3=Wayne | last4=Mitchell | first4=Adam W. M. }}</ref>

===Depiction===
{{Main|Human figure (aesthetics)|Figure drawing}}
[[File:Corinth stehender Mädchenakt.jpg|thumb|upright=0.6|Figure drawing by [[Lovis Corinth]] (before 1925)]]

Anatomy has served the visual arts since Ancient Greek times, when the 5th century BC sculptor [[Polykleitos]] wrote his ''Canon'' on the [[Mathematics and art#Polykleitos|ideal proportions of the male nude]].<ref name=Stewart>{{cite journal |last1=Stewart |first1=Andrew |title=Polykleitos of Argos," One Hundred Greek Sculptors: Their Careers and Extant Works |journal=[[Journal of Hellenic Studies]] |date=November 1978 |volume=98 |pages=122–131 |doi=10.2307/630196|jstor=630196 |s2cid=162410725 }}</ref> In the [[Italian Renaissance]], artists from [[Piero della Francesca]] ({{Circa|1415}}–1492) onwards, including [[Leonardo da Vinci]] (1452–1519) and his collaborator [[Luca Pacioli]] ({{Circa|1447}}–1517), learnt and wrote about the rules of art, including [[visual perspective]] and the proportions of the human body.<ref>{{cite web |title=Leonardo |url=http://www.dartmouth.edu/~matc/math5.geometry/unit14/unit14.html |publisher=[[Dartmouth College]] |access-date=2 September 2016 |archive-date=21 August 2009 |archive-url=https://web.archive.org/web/20090821025325/http://www.dartmouth.edu/~matc/math5.geometry/unit14/unit14.html |url-status=dead }}</ref>

===History of anatomy===
{{Main|History of anatomy}}
[[File:Externarvm hvmani corporis sedivm partivmve, 1543..JPG|thumb|Two facing pages of text with woodcuts of naked male and female figures, in the ''Epitome'' by [[Andreas Vesalius]], 1543]]

In [[Ancient Greece]], the ''[[Hippocratic Corpus]]'' described the anatomy of the skeleton and muscles.<ref>{{cite book |last=Gillispie |first=Charles Coulston | author-link=Charles Coulston Gillispie |title=Dictionary of Scientific Biography | volume=VI | pages=419–427 |year=1972 | publisher=[[Charles Scribner's Sons]] | location=New York}}</ref> The 2nd century physician [[Galen of Pergamum]] compiled classical knowledge of anatomy into a text that was used throughout the Middle Ages.<ref name=BritBrit-Galen>{{cite encyclopedia |chapter-url=https://www.britannica.com/EBchecked/topic/223895/Galen-of-Pergamum |title=Encyclopædia Britannica 2006 Ultimate Reference Suite DVD |chapter=Galen of Pergamum |first=Vivian | last=Nutton |author-link=Vivian Nutton}}</ref> In the [[Renaissance]], [[Andreas Vesalius]] (1514–1564) pioneered the modern study of human anatomy by dissection, writing the influential book ''[[De humani corporis fabrica]]''.<ref>{{cite web |url=http://ceb.nlm.nih.gov/proj/ttp/books.htm |title=Vesalius's ''De Humanis Corporis Fabrica'' |publisher=Archive.nlm.nih.gov |access-date=29 August 2010 }}</ref><ref>{{cite web|title=Andreas Vesalius (1514–1567)|url=http://www.ingentaconnect.com/content/apl/uivs/1999/00000012/00000003/art00002?crawler=true|date=1 May 1999|publisher=Ingentaconnect|url-status=dead|archive-url=https://web.archive.org/web/20111105145007/http://www.ingentaconnect.com/content/apl/uivs/1999/00000012/00000003/art00002?crawler=true|archive-date=5 November 2011|access-date=29 August 2010}}</ref> Anatomy advanced further with the invention of the [[microscope]] and the study of the cellular structure of tissues and organs.<ref name=BritMicro>{{cite encyclopedia |url=https://www.britannica.com/EBchecked/topic/22980/anatomy/283/Microscopic-anatomy |title=Microscopic anatomy |encyclopedia=[[Encyclopædia Britannica]] |access-date=14 October 2013}}</ref> Modern anatomy uses techniques such as [[magnetic resonance imaging]], [[X-ray computed tomography|computed tomography]], [[fluoroscopy]] and [[Medical ultrasonography|ultrasound imaging]] to study the body in unprecedented detail.<ref>{{cite web | url=http://www.mhhe.com/biosci/ap/foxhumphys/student/olc/h-reading1.html | title=Anatomical Imaging | publisher=[[McGraw Hill Higher Education]] | year=1998 | access-date=25 June 2013 | archive-url=https://web.archive.org/web/20160303232044/http://www.mhhe.com/biosci/ap/foxhumphys/student/olc/h-reading1.html | archive-date=3 March 2016 | url-status=dead }}</ref>

===History of physiology===
{{Main|History of physiology}}

The study of human physiology began with [[Hippocrates]] in Ancient Greece, around 420 BCE, and with [[Aristotle]] (384–322 BCE) who applied critical thinking and emphasis on the relationship between structure and function. [[Galen]] ({{Circa|126|199}}) was the first to use experiments to probe the body's functions.<ref>{{cite journal | first1=C. | last1=Fell | first2=F. | last2=Griffith Pearson| title=Thoracic Surgery Clinics: Historical Perspectives of Thoracic Anatomy | journal=Thorac Surg Clin |date=November 2007 | volume=17 | issue=4 | pages=443–448, v | doi=10.1016/j.thorsurg.2006.12.001| pmid=18271159 }}</ref> The term physiology was introduced by the French physician [[Jean Fernel]] (1497–1558).<ref name=NMT/> In the 17th century, [[William Harvey]] (1578–1657) described the [[circulatory system]], pioneering the combination of close observation with careful experiment.<ref>{{Cite journal | first=Carl | last=Zimmer | author-link=Carl Zimmer| title=Soul Made Flesh: The Discovery of the Brain – and How It Changed the World | journal=J Clin Invest | year=2004 | volume=114 | issue=5 | pages=604 | doi=10.1172/JCI22882| pmc=514597 }}</ref> In the 19th century, physiological knowledge began to accumulate at a rapid rate with the [[cell theory]] of [[Matthias Jakob Schleiden|Matthias Schleiden]] and [[Theodor Schwann]] in 1838, that organisms are made up of cells.<ref name=NMT>{{cite web |last1=Newman |first1=Tim |title=Introduction to Physiology: History And Scope |url=http://www.medicalnewstoday.com/articles/248791.php |work=[[Medicine News Today]] |access-date=2 September 2016}}</ref> [[Claude Bernard]] (1813–1878) created the concept of the ''[[milieu interieur]]'' (internal environment), which [[Walter Cannon]] (1871–1945) later said was regulated to a steady state in [[homeostasis]]. In the 20th century, the physiologists [[Knut Schmidt-Nielsen]] and [[George Bartholomew (biologist)|George Bartholomew]] extended their studies to [[comparative physiology]] and [[ecophysiology]].<ref>{{Cite book| last=Feder | first=Martin E. | title=New directions in ecological physiology | year=1987 | publisher=[[Cambridge University Press]] | location=New York | isbn=978-0-521-34938-3 }}</ref> Most recently, [[evolutionary physiology]] has become a distinct subdiscipline.<ref>{{Cite journal | first1=Theodore Jr. | last1=Garland | author1-link=Theodore Garland, Jr. | last2=Carter | first2=P. A. | title=Evolutionary physiology | journal=[[Annual Review of Physiology]] | year=1994 | issue=1 | pages=579–621 | url=http://www.biology.ucr.edu/people/faculty/Garland/GarlCa94.pdf | doi=10.1146/annurev.ph.56.030194.003051 | volume=56 | pmid=8010752 | access-date=20 November 2013 | archive-date=12 April 2021 | archive-url=https://web.archive.org/web/20210412150229/https://biology.ucr.edu/people/faculty/Garland/GarlCa94.pdf | url-status=dead }}</ref>

==See also==
{{Portal|Biology|Medicine}}
* {{annotated link|Anatomical model}}
* {{annotated link|Body image}}
* {{annotated link|Cell physiology}}<!--does this need to be integrated in text?-->
* {{annotated link|Comparative anatomy}}
* {{annotated link|Comparative physiology}}
* {{annotated link|Development of the human body}}
* {{annotated link|Glossary of medicine}}
* {{annotated link|Human physical appearance}}
* {{annotated link|Medicine}}
* [[Outline of human anatomy]]
* [[Organ system]]
* ''[[The Birth of the Clinic|The Birth of the Clinic: An Archaeology of Medical Perception]]''

==References==
{{Reflist}}

===Books===
* {{cite book|title=Ganong's Review of Medical Physiology|year=2016|isbn=978-0-07-182510-8|ref={{harvid|Ganong's|2016}}|last1=Boitano|first1=Scott|last2=Brooks|first2=Heddwen L.|last3=Barman|first3=Susan M.|last4=Barrett|first4=Kim E.|author4-link=Kim Barrett}}
* {{cite book|others=Editor-in-chief, [[Susan Standring]]|title=Gray's anatomy: the anatomical basis of clinical practice|date=2008|publisher=Churchill Livingstone|location=London|isbn=978-0-8089-2371-8|edition=40th|ref={{harvid|Gray's Anatomy|2008}}}}

==External links==
{{Wikisource portal|Human Anatomy}}
{{Commons category}}
{{Wiktionary|body}}
{{Wikibooks|Human Physiology}}
* ''[https://web.archive.org/web/20140126181303/http://www.wdl.org/en/item/4299/ The Book of Humans]'' (from the late 18th and early 19th centuries)
* [https://web.archive.org/web/19971210121754/http://www.innerbody.com/ Inner Body]
* [http://link.library.utoronto.ca/anatomia/ Anatomia 1522–1867: Anatomical Plates from the Thomas Fisher Rare Book Library]

{{Human system and organs}}
{{Physiology types}}
{{Medicine}}
{{Authority control}}

{{DEFAULTSORT:Human Body}}
[[Category:Human body| ]]
[[Category:Human physiology| ]]
[[Category:Human anatomy| ]]

Revision as of 06:26, 16 June 2023

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Kurzgesagt
Kurzgesagt - In a Nutshell
Pronunciation
  • /ˌkʊərtsɡəˈzɑːkt/
FormationJuly 9, 2013; 11 years ago (2013-07-09)
FounderPhilipp Dettmer
TypePrivate GmbH
PurposeEdutainment
Location
OwnerPhilipp Dettmer
Staff64[2] (in 2023)
Websitekurzgesagt.org
YouTube information
Channel
Years active2013–present
Genres
  • Animation
  • Education
  • Science
  • Philosophy
Subscribers20.5 million[3]
Total views2.30 billion[3]
100,000 subscribers2014
1,000,000 subscribers2015
10,000,000 subscribers2019
Last updated: May 16 2023

T

TROLL BY THE KCA

Kurzgesagt (/ˌkʊərtsɡəˈzɑːkt/; German for "In a nutshell", "Long story short" or "in short" (with "in a few words" also being a possible but less common translation in English) is a German-made animation and design studio founded by Philipp Dettmer. The studio's YouTube channel focuses on minimalistic animated educational content,[4] using a flat and 3D design style. It discusses scientific, technological, political, philosophical, and psychological subjects.[5]

Narrated by Steve Taylor, videos on the channel are normally four to sixteen minutes. Many videos are also available through other language-specific channels, such as in German through the channel Dinge Erklärt – Kurzgesagt, and in Spanish through En Pocas Palabras - Kurzgesagt. Some of their videos are also available in French, Hindi, Arabic, Brazilian Portuguese, Japanese and Korean.[6][7]

As of 25 May 2023, with over 20 million subscribers and over 180 videos, the studio's original English language channel was the world's 207th most subscribed channel.[8]

History

Patrizia Mosca, Chief operating officer at Kurzgesagt, speaks at the Internet Days in Stockholm, 2018.

The Kurzgesagt YouTube channel was created on 9 July 2013, shortly after the founder, Philipp Dettmer, graduated from Munich University of Applied Sciences.[9] The first video, which explained evolution, was published two days later with the voice of Steve Taylor, who still serves as commentator as of 2023.[10] The videos were much more popular than expected, and in six years the channel went from a project worked on during Dettmer's free time to a design studio with over forty employees. The studio has even received commissions and grants from a number of established, independent institutions.[citation needed] In 2015, Kurzgesagt was commissioned to create a video on the end of disease by the Bill and Melinda Gates Foundation.[11]

This video about the COVID-19 pandemic, called The Coronavirus Explained & What You Should Do and released in March 2020, was posted on all three of their channels and shared how the human body responds to COVID-19 and how effective the measures in evading SARS-CoV-2.[12] The English version has over 88 million views, making it the most viewed video on the channel.[13] A study published in Visual Resources, said that the video "is an example of an aesthetically compelling explanation of the biological processes of a Covid infection" and it "includes fantastical depictions that convey the message in a more comprehensible straightforward manner."[14]

Outside of the grants from patrons, Kurzgesagt, at least the German branch, was primarily financially supported by the network Funk of ARD and ZDF since September 2017. Kurzgesagt's German Branch announced their departure from Funk in January 2023.[15][16][17][18]

Kurzgesagt has been the recipient of several awards. In 2019, Kurzgesagt became the first German channel to surpass 10 million subscribers on YouTube.[19] In December 2020, fellow YouTuber Marques Brownlee honored Kurzgesagt, with his "Streamys Creator Honor" award in the 10th Streamy Awards.[20]

Immune: A journey into the mysterious system that keeps you alive

In November 2021, Kurzgesagt announced the release of their first book, Immune: A journey into the mysterious system that keeps you alive, written by Phillip Dettmer, the channel's founder.[21]

A publication by the Foundation for the Rights of Future Generations, a German think tank, recommended the book among others for books on the COVID-19 pandemic, describing it as "full of stories of invasion, strategy, defeat, and noble self-sacrifice," in introducing the complex world of the immune system.[22] Daniel M. Davis, the Head of Life Sciences and Professor of Immunology at Imperial College London, described it as "the feast we have been waiting for" due to the public interest in the mechanisms of the immune system, such as Antibodies, T cells, and B cells, during the COVID-19 pandemic, which were "rarely discussed outside of research labs and scientific talks."[23] In the book, the author acknowledges the feedback and help of a Dr. James Gurney, Professor Thomas Brocker, the director of the Munich Institute for Immunology, and Professor Maristela Martins de Camargo of the University of São Paulo.[24]

Sources of funding

In 2015, the channel received a 570,000 US dollar grant from the Bill and Melinda Gates Foundation[11] who later became one of their key sponsors. Kurzgesagt have made videos calling for investment in novel technologies the foundation also supports, such as carbon capture and artificial meat, as well as arguing for an optimistic view on the future of climate change and economic inequality, a view shared by Bill Gates.[25][26]

In March 2022, Kurzgesagt received 2.97 million euros in a grant via Open Philanthropy,[27] which the channel said was being used for translating their videos to various languages, and for funding the creation of content for TikTok.[28] Open Philanthropy supports positions that Kurzgesagt has defended, such as effective altruism and Longtermism.[29] The channel has received a smaller grant from the John Templeton Foundation.[30]

In a January 2023 statement,[31] Kurzgesagt stated that 65% of their income from 2020 to 2022 came from viewers via the sale of merchandise from their shop, such as mugs, posters and toys, crowdfunding via Patreon, and Google AdSense revenue, with commercial or institutional sponsorships, and grants accounting for only 24% of income. The statement said that the channel treats all data skeptically, that their sources for statements are always given, and that all research work is done in-house, with no editorial influence from sponsors or donors—a condition they say is included in every deal they have signed.[31]

Reliability of videos

While some commentators have praised Kurzgesagt's videos for their reliability and fact-checking,[32] some of their earlier work received criticism. In 2016, the Art Libraries Society of North America criticized the studio's occasional lack of credible sources and professional consultation, and use of emotive language.[33]

In 2019, Kurzgesagt released a video saying that while they now had all their arguments fact-checked by experts, they had not always done so in the past. They added they were deleting two of their videos from 2015 that failed their current standards, including their video titled "Addiction".[34] A collaboration between Kurzgesagt and journalist Johann Hari, "Addiction" came to be one of the most popular on their channel at the time, despite also being one of their most criticized.[35] The video was accused of misleadingly summarizing the conclusions of the contentious Rat Park experiments.[35] Kurzgesagt acknowledged they had presented one argument as fact, and had not considered other theories on the matter.[34]

See also

References

  1. ^ Jackson, Ryan (April 28, 2021). "The 'ultimate guide to black holes' will spaghettify your brain". CNET. Archived from the original on April 29, 2021.
  2. ^ "About". Kurzgesagt. Retrieved March 28, 2023.
  3. ^ a b "About Kurzgesagt – In a Nutshell". YouTube.
  4. ^ Lucas, Terry; Abd Rahim, Ruslan (March 15, 2017). "The Similarities and Nuances of Explicit Design Characteristics of Well-Received Online Instructional Animations". Animation. 12 (1). SAGE Publishing: 80–99. doi:10.1177/1746847717690671. ISSN 1746-8477. S2CID 64818185.
  5. ^ Dubovi, Ilana; Tabak, Iris (October 1, 2020). "An empirical analysis of knowledge co-construction in YouTube comments". Computers & Education. 156. Elsevier: 7. doi:10.1016/j.compedu.2020.103939. ISSN 0360-1315. S2CID 219914081.
  6. ^ "Dinge Erklärt – Kurzgesagt". YouTube. Retrieved March 19, 2022.
  7. ^ "Kurzgesagt – In a Nutshell". YouTube. Retrieved July 30, 2022.
  8. ^ "Kurzgesagt – In a Nutshell". Social Blade. Retrieved May 1, 2023.
  9. ^ Brien, Jörn (November 6, 2019). "Youtube: Kurzgesagt – In a Nutshell knackt als erster deutscher Kanal die 10-Millionen-Marke" [Youtube: In a nutshell – In a Nutshell is the first German channel to break the 10 million mark]. t3n Magazin (in German). Retrieved November 3, 2019.
  10. ^ "English Voice - Voice Pool English Voice-Over". Voice Pool. Retrieved October 17, 2022.
  11. ^ a b "Kurzgesagt". Bill & Melinda Gates Foundation. November 2015. Retrieved March 14, 2021.
  12. ^ Hart, Matthew (May 19, 2020). "A Look at How the Virus that Causes COVID-19 Infects People". Nerdist.
  13. ^ "Video explainer on the coronavirus has more than 17.5 million views". Cochrane Today. March 26, 2020.
  14. ^ Ehrlich, Nea (July 2, 2020). "Viral Imagery: The Animated Face of Covid-19". Visual Resources. 36 (3). Routledge: 247–261. doi:10.1080/01973762.2021.1960777. ISSN 0197-3762. S2CID 241823806.
  15. ^ "funk-Format 'Kurzgesagt' fragt: 'Brauchen wir Atomkraft, um den Klimawandel zu stoppen?'" [funk-format 'In a nutshell' asks: 'Do we need nuclear power to stop climate change?']. Braunschweiger Zeitung (in German). November 18, 2020. Archived from the original on January 22, 2021. Retrieved November 21, 2020.
  16. ^ Fehrensen, Täubner; Täubner, Mischa (2019). "Acht Minuten Welterklärung - brand eins online" [Eight minutes of explanation of the world]. brand eins (in German). Archived from the original on March 1, 2021. Retrieved August 4, 2021.
  17. ^ Lux, Torben (June 17, 2020). "So hat Kurzgesagt-Gründer Philipp Dettmer mit Erklärvideos eine Milliarde Views gemacht" [Kurzgesagt founder Philipp Dettmer has made a billion views with explanatory videos]. ORM (in German). Retrieved November 21, 2020.
  18. ^ Dinge Erklärt - Kurzgesagt (January 19, 2023). "Warum wir funk verlassen haben!" [Why we left funk!]. YouTube (in German). Retrieved January 19, 2023.
  19. ^ Weil, Andrew (December 5, 2019). "YouTube's 2019 Rewind focuses on the basics after 2018 video fiasco". Wusa9. Retrieved February 27, 2020.
  20. ^ Hale, James (December 12, 2020). "Here Are Your 2020 Streamy Award Winners". Tubefilter.
  21. ^ Kurzgesagt – In a Nutshell (August 10, 2021). "How The Immune System ACTUALLY Works – IMMUNE". YouTube. Retrieved September 18, 2022.
  22. ^ Tremmel, Jörg (2021). "Recommendations of new books on the pandemic". Intergenerational Justice Review. 7 (1). doi:10.24357/igjr.7.1.912. ISSN 2190-6335.
  23. ^ Davis, Daniel M. (November 5, 2021). "Immunology meets the masses Immune: A Journey into the Mysterious System That Keeps You Alive Philipp Dettmer Random House, 2021. 368 pp". Science. 374 (6568): 697. doi:10.1126/science.abm0134. ISSN 0036-8075. PMID 34735237. S2CID 243761609.
  24. ^ Dettmer, Philipp (November 2, 2021). Immune : a journey into the mysterious system that keeps you alive. ISBN 978-0593241332.
  25. ^ Rathi, Akshat (February 2, 2022). "Bill Gates Invests in Carbon Capture Startup After Tech Breakthrough". Bloomberg.com. Retrieved January 29, 2023.
  26. ^ Morgan, Rick (March 23, 2018). "Bill Gates and Richard Branson are betting lab-grown meat might be the food of the future". CNBC. Retrieved January 29, 2023.
  27. ^ "Grants". Open Philanthropy. Retrieved January 29, 2023.
  28. ^ "Kurzgesagt Statement to the Conflict of Interest Allegations". reddit. January 23, 2023. Retrieved January 29, 2023.
  29. ^ "Kurzgesagt — Short-form Video Content". Open Philanthropy. July 18, 2022. Retrieved January 29, 2023.
  30. ^ "An Analysis of the Distribution of Degrees of Intelligence across Animal Groups". Templeton World Charity. Retrieved January 29, 2023.
  31. ^ a b "Kurzgesagt Statement to the Conflict of Interest Allegations". reddit. Retrieved January 29, 2023.
  32. ^ Humprhies, Suzanne (January 9, 2021). "What We're Watching: Kurzgesagt Explores Big Questions with Bite-Size Videos". Review Geek. Archived from the original on April 18, 2021.
  33. ^ Gumb, Lindsey (April 2016). "Multimedia Technology Review — Kurzgesagt". Art Libraries Society of North America. Archived from the original on April 15, 2021.
  34. ^ a b "Can You Trust Kurzgesagt Videos?", Kurzgesagt channel on YouTube, retrieved June 26, 2021
  35. ^ a b Stenn, Lili (March 14, 2019). "YouTuber Coffee Break Accuses Kurzgesagt of Being Untrustworthy, Founder Responds". Rogue Rocket. Archived from the original on April 23, 2021.
  • No URL found. Please specify a URL here or add one to Wikidata. Edit this at Wikidata
  • "Dinge Erklaert Kurzgesagt" [Brief Explanations of Things] (in German). Funk. January 22, 2018.
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