Usingizi (kwa Kiingereza "sleep") ni hali ya binadamu na wanyama kupumzika kwa mwili na akili.

Usingizi hutokea wakati mapigo ya moyo na upumuaji hupungua kwa ngazi zao za chini. Misuli yako inatulia na inaweza kuwa vigumu kukuamsha. Huwa hujitambui wala hujitawali sawasawa.

Tanbihi

Vyanzo

• Brown Ritchie E.; Basheer Radhika; McKenna James T.; Strecker Robert E.; McCarley Robert W. (2012). "Control of Sleep and Wakefulness". Physiological Reviews 92 (3): 1087–1187. PMC 3621793. PMID 22811426. doi:10.1152/physrev.00032.2011. 
• Parmeggiani, Pier Luigi, & Ricardo A. Velluti, eds. (2005). The Physiologic Nature of Sleep. London: Imperial College Press. ISBN 1-86094-557-0.
• Parmeggiani, Pier Luigi (2011). Systemic Homeostasis and Poikilostasis in Sleep: Is REM Sleep a Physiological Paradox? London: Imperial College Press. ISBN 978-1-94916-572-2
• Turek, Fred W. & Phyllis C. Zee, eds. (1999). Regulation of Sleep and Circadian Rhythms. New York: Marcel Dekker, Inc. ISBN 0-8247-0231-X

Viungo vya nje

Wikimedia Commons ina media kuhusu:

Sleep

• Rethinking Sleep, David K. Randall, New York Times, September 2012
• How to Sleep, James Hamblin, The Atlantic, January 2017

Makala hii kuhusu mambo ya biolojia bado ni mbegu. Je, unajua kitu kuhusu Usingizi kama historia yake au mahusiano yake na mada nyingine? Labda unaona habari katika Wikipedia ya Kiingereza au lugha nyingine zinazofaa kutafsiriwa? Basi unaweza kuisaidia Wikipedia kwa kuihariri na kuongeza habari.