Navel

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For other uses, see Navel (disambiguation).
"Belly button" redirects here. For other uses, see Belly button (disambiguation).
Navel
Ombelico.JPG
human navel
Latin Umbilicus
Artery Umbilical artery
Vein Umbilical vein
Precursor Ductus venosus
Anatomical terminology

The navel (clinically known as the umbilicus, colloquially known as the belly button, umbilical dip or tummy button) is a scar[1] on the abdomen at the attachment site of the umbilical cord. All placental mammals have a navel, and it is quite conspicuous in humans.[2] Other animals' navels tend to be smoother and flatter, often nothing more than a thin line, and are often obscured by fur.[3][unreliable medical source?]

Structure[edit]

What is commonly referred to as an "outie" navel (female)
Female navel
The navel is the centre of the circle in this drawing of the Vitruvian Man by Leonardo da Vinci

The umbilicus is a prominent mark on the abdomen, with its position being relatively consistent amongst humans. The skin around the waist at the level of the umbilicus is supplied by the tenth thoracic spinal nerve (T10 dermatome). The umbilicus itself typically lies at a vertical level corresponding to the junction between the L3 and L4 vertebrae,[4] with a normal variation among people between the L3 and L5 vertebrae.[5] The umbilicus forms a visible depression on the skin of the abdomen, and the underlying abdominal muscle layers also present a concavity; thinness at this point contributes to a relative structural weakness, making it susceptible to hernia.[citation needed] During pregnancy, the uterus presses the navel of the pregnant woman outward; it usually retracts again after birth.[citation needed]

The umbilicus is used to visually separate the abdomen into quadrants. The navel is the center of the circle enclosing the spread-eagle figure in Leonardo da Vinci's Vitruvian Man drawing. The navel is rarely the focus in contemporary art and literature.[6][unreliable medical source?]

Innies and outies[edit]

In humans, the navel scar can appear as a depression (often referred to colloquially as an "innie") or as a protrusion ("outie"). About 90% of humans have innies.[3] The occurrence of an "outie" navel is caused by the extra scar tissue left from the umbilical cord[7][unreliable medical source?] or from umbilical hernias, although the latter does not always cause an "outie" to develop. Frequently separated into just those two categories, navels vary quite widely among people in terms of size, shape, depth, length, and overall appearance. As navels are scars, and not defined by genetics, they can serve as a way of distinguishing between identical twins in the absence of other identifiable marks.[citation needed]

Clinical significance[edit]

Disorders[edit]

The navel can be involved in umbilical sinus or fistula, which in rare cases can lead to menstrual or fecal discharge from the navel. Menstrual discharge from the umbilicus is associated with umbilical endometriosis, a rare disorder.[8][9]

Society and culture[edit]

There are many customs, fashion and taboos associated with the human navel in the human social context. These have varied in ideas and trends across regions and throughout history. Social mores about the navel in clothing and human social traditions has been given diverse narratives and significance across human social world.[citation needed]

Other animals[edit]

See also[edit]

References[edit]

  1. ^ Ins and outs of a beautiful belly button; As Katie Holmes shocks navel-gazers. Goliath.ecnext.com (30 June 2011).
  2. ^ Important Facts About Navel. Memorylogix.com (23 April 2011).
  3. ^ a b The Ins and Outs of Belly Buttons. Divinecaroline.com (27 May 2009).
  4. ^ Ellis, Harold (2006). Clinical Anatomy: Applied Anatomy for Students and Junior Doctors. New York: Wiley. ISBN 1-4051-3804-1. [1]
  5. ^ Basic Human Anatomy – O'Rahilly, Müller, Carpenter & Swenson – Chapter 25: Abdominal walls. Dartmouth Medical School. Retrieved November 2010
  6. ^ REGINA HACKETT (30 May 2002). "Dunning's examination of torsos is a truly navel experience". Seattle Post-Intelligencer. Retrieved 19 March 2012. 
  7. ^ http://www.divinecaroline.com/self/self-discovery/ins-and-outs-belly-buttons
  8. ^ Bagade, Pallavi V; Guirguis, Mamdouh M (2009). "Menstruating from the umbilicus as a rare case of primary umbilical endometriosis: a case report". Journal of Medical Case Reports 3 (1): 9326. doi:10.1186/1752-1947-3-9326. ISSN 1752-1947. 
  9. ^ http://pediatriceducation.org/2008/06/02/, retrieved 2014-06-02  Missing or empty |title= (help)