Wikipedia:Main Page history/2021 May 28
From today's featured articleThe menstrual cycle is a series of natural changes in hormone production and the structures of the uterus and ovaries of the human female reproductive system that make pregnancy possible. Naturally occurring hormones drive two concurrent and coordinated cycles that last about 28 days. The ovarian cycle controls the production and release of eggs and the release of the hormones estrogen and progesterone. The uterine cycle governs the preparation and maintenance of the lining of the uterus (endometrium) to receive a fertilized egg. Menstruation, a "period" in common parlance, begins on day one of the cycle, and lasts for about five days. Around day fourteen, an egg is usually released from the ovary. Estrogen stimulates the uterus lining to thicken to accommodate an embryo should fertilization occur. If implantation does not occur, the lining is released during menstruation. Menarche (the first period) usually occurs around age twelve, and menstrual cycles usually continue for 30–45 years until menopause. (Full article...)
Recently featured:
Did you know ...
|
In the news
On this dayMay 28: Republic Day in Armenia (1918); Republic Day in Azerbaijan (1918)
|
From today's featured list
Taiwan, officially the Republic of China, has 112 diplomatic missions across the world as of December 2020. Due to the One-China policy, other countries are only allowed to maintain relations with either Taiwan or the mainland-based People's Republic of China. As most countries have changed their recognition to the latter over time, only 17 of Taiwan's diplomatic missions have official status, consisting of fifteen embassies and two consulate-generals. Despite these barriers, 57 United Nations members maintain relations with Taiwan on an unofficial basis. To serve these locations and other places throughout the world, 92 semi-official representative offices are utilized for matters that would otherwise be handled by embassies or consulates. Taiwan has established informal representation in China's two special administrative regions as well. In Hong Kong, the Taipei Economic and Cultural Office in Hong Kong provides services similar to a consulate, while relations to Macau are handled by the Taipei Economic and Cultural Office in Macau. (Full list...)
Today's featured picture
William Birney (May 28, 1819 – August 14, 1907) was a professor, Union Army general during the American Civil War, attorney, and author. An ardent abolitionist, he was one of three superintendents in charge of enlisting colored troops into the Union Army, and in that capacity organized seven regiments. After the war, he established a law practice in Washington, D.C., and after retiring, wrote profusely on religion and history, and authored a biography of his father, James G. Birney. Photograph credit: unknown; restored by Adam Cuerden
Recently featured:
|
Other areas of Wikipedia
- Community portal – Bulletin board, projects, resources and activities covering a wide range of Wikipedia areas.
- Help desk – Ask questions about using Wikipedia.
- Local embassy – For Wikipedia-related communication in languages other than English.
- Reference desk – Serving as virtual librarians, Wikipedia volunteers tackle your questions on a wide range of subjects.
- Site news – Announcements, updates, articles and press releases on Wikipedia and the Wikimedia Foundation.
- Village pump – For discussions about Wikipedia itself, including areas for technical issues and policies.
Wikipedia's sister projects
Wikipedia is hosted by the Wikimedia Foundation, a non-profit organization that also hosts a range of other projects:
-
Commons
Free media repository -
MediaWiki
Wiki software development -
Meta-Wiki
Wikimedia project coordination -
Wikibooks
Free textbooks and manuals -
Wikidata
Free knowledge base -
Wikinews
Free-content news -
Wikiquote
Collection of quotations -
Wikisource
Free-content library -
Wikispecies
Directory of species -
Wikiversity
Free learning tools -
Wikivoyage
Free travel guide -
Wiktionary
Dictionary and thesaurus
Wikipedia languages
This Wikipedia is written in English. Many other Wikipedias are available; some of the largest are listed below.
-
1,000,000+ articles
-
250,000+ articles
-
50,000+ articles