The navel (clinically known as the umbilicus, commonly known as the belly button or tummy button) is a protruding, flat, or hollowed area on the
abdomen at the attachment site of the
umbilical cord. All
placental mammals have a navel, although it is generally more conspicuous in humans.
Structure
The umbilicus is used to visually separate the abdomen into quadrants.
The umbilicus is a prominent
scar on the abdomen, with its position being relatively consistent among 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, with a normal variation among people between the L3 and L5 vertebrae.
Parts of the adult navel include the "umbilical cord remnant" or "umbilical tip", which is the often protruding scar left by the detachment of the umbilical cord. This is located in the center of the navel, sometimes described as the ''belly button''. Around the cord remnant, is the "umbilical collar", formed by the dense fibrous
umbilical ring
The umbilical ring is a dense fibrous ring surrounding the umbilicus at birth. At about the sixth week of embryological development, the midgut herniates through the umbilical ring; six weeks later it returns to the abdominal cavity and rotates ...
. Surrounding the umbilical collar is the periumbilical skin. Directly behind the navel is a thick fibrous cord formed from the umbilical cord, called the
urachus, which originates from the
bladder
The urinary bladder, or simply bladder, is a hollow organ in humans and other vertebrates that stores urine from the kidneys before disposal by urination. In humans the bladder is a distensible organ that sits on the pelvic floor. Urine en ...
.
Forms
The navel is unique to each individual due to its being a scar, and various general forms have been classified by medical practitioners.
*Outie: A navel consisting of the umbilical tip protruding past the periumbilical skin is an outie. Essentially any navel which is not concave.
**Swirly/spiral: A rare form in which the umbilical cord scar forms a swirl shape.
**Split: The protruding umbilical cord scar extends outwards, but is cleft in two by a fissure which extends part or all the way through the umbilical cord scar. This form is similar in appearance to a coffee bean.
**Protrusion: The umbilical cord remnant is completely divulged, exposing the full umbilical scar.
**Circlet: Although the entirety of the umbilical cord remnant sits out with the umbilical collar, the centre of the knot is inset by a deep fissure. Unlike a split outie, in this form the fissure is contained centrally and does not extend past the umbilical cord remnant in any direction, much akin to a 'donut' shape.
*Innie: A navel in which the umbilical tip does not protrude past the periumbilical skin. Any navel which is concave.
**Round: Round navels are completely circular with no hooding.
**Vertical: Some navels present in the form of a more elongate hollow parallel with the
linea alba.
**Oval: This form consists of three variants; superior hooding, inferior hooding, no hooding.
**T-shaped: As the name states, the scar is in the shape of a T, and may have superior hooding to various extent.
**Horizontal: The scar is the least visible, as the natural lines of the
tendinous intersection fold over the scar.
*Distorted: Any navel which does not fit well into any of the other categories.
File:Carlson Twins.jpg, Both Carlson Twins
Kyle and Lane Carlson (born December 24, 1978) are American identical twin brothers known as the Carlson Twins. They work together as male fashion models.
Biography
The twins were born in Stillwater, Minnesota, Kyle six minutes after Lane. ...
have swirly navels
File:T-shaped navel.jpg, A t-shaped navel
File:Navel 2 - Picture by Giovanni Dall'Orto, July 25 2010.jpg, One of many variations of an outie
File:Belly Button.jpg, An innie navel
File:Human navel, female.jpg, alt=, Closeup of a female navel
Clinical significance
Disorders
Outies are sometimes mistaken for
umbilical hernia
An umbilical hernia is a health condition where the abdominal wall behind the navel is damaged. It may cause the navel to bulge outwards—the bulge consisting of abdominal fat from the greater omentum or occasionally parts of the small intestine. ...
s; however, they are a completely different shape with no health concern, unlike an umbilical hernia. The navel (specifically abdominal wall) would be considered an umbilical hernia if the protrusion were 5
centimeters or more. The diameter of an umbilical hernia is usually 1/2-inch or more.
Navels that are concave are nicknamed "innies". While the shape of the human navel may be affected by long term changes to diet and exercise, unexpected change in shape may be the result of
ascites.
In addition to change in shape being a possible side effect from ascites and umbilical hernias, 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 a rare disorder associated with umbilical
endometriosis.
Other disorders
*
Omphalitis, an inflammatory condition of the umbilicus in the
newborn, usually caused by a bacterial infection.
* Omphalophobia is the fear of belly buttons. People suffering from omphalophobia are terrified of belly buttons—their own or, in some cases, those of others. They do not like touching their belly buttons (or even other people touching it). Sometimes just seeing a belly button is enough to make them feel disgusted or terrified.
Surgery
To minimize scarring, the navel is a recommended site of incision for various surgeries, including transgastric
appendicectomy,
gall bladder surgery, and the
umbilicoplasty procedure itself.
Fashion, society and culture
The public exposure of the male and female
midriff and bare navel was considered
taboo at times in the past in
Western cultures, being considered
immodest or
indecent
Inappropriateness refers to standards or ethics that are typically viewed as being negative in a society. It differs from things that are illicit in that inappropriate behavior does not necessarily have any accompanying legal ramifications.
Co ...
. Female navel exposure was banned in some jurisdictions, but community perceptions have changed to this now being acceptable.
The
crop top is a shirt that often exposes the belly button and has become more common among young people. Exposure of the male navel has rarely been stigmatised and has become particularly popular in recent years, due to the strong resurgence of the male crop top and male
navel piercing.
The navel and midriff are often also displayed in
bikinis, or when
low-rise pants
Low-rise pants, also known as "low-cut jeans", "lowriders" or "rap pants", are a type of pants that sit low on, or below, the hips, usually at least 8 centimetres (3 inches) lower than the navel. Low-rise pants have been available since the ...
are worn.
While the West was relatively resistant to navel-baring clothing until the 1980s, it has long been a fashion with
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area, the List of countries and dependencies by population, second-most populous ...
n women,
[Banerjee, Mukulika & Miller, Daniel (2003) ''The Sari''. Oxford; New York: Berg ] often displayed with
saris or
lehenga The ''lehenga'', ''lehnga'' or ''langa'' (also known as a ''ghagra'' or ''gagra'', ''chaniya'', ''pavadai'', or ''lacha'') is a form of ankle-length skirt from the Indian subcontinent. Different patterns and styles of traditional embroidery are used ...
s.
The
Japanese have long had a special regard for the navel. During the early
Jōmon period in northern Japan, three small balls indicating the breasts and navel were pasted onto flat clay objects to represent the female body. The navel was exaggerated in size, informed by the belief that the navel symbolized the center where life began.
In Arabic-
Levant
The Levant () is an approximate historical geographical term referring to a large area in the Eastern Mediterranean region of Western Asia. In its narrowest sense, which is in use today in archaeology and other cultural contexts, it is ...
ine culture,
belly dancing
Belly dance ( Egyptian Arabic: رقص بلدي, translated: Dance of the Country/Folk Dance, romanized: Raks/Raas Baladi) is a dance that originates in Egypt. It features movements of the hips and torso. It has evolved to take many different ...
is a popular art form that consists of dance movements focused on the torso and navel.
Buddhism
Buddhism ( , ), also known as Buddha Dharma and Dharmavinaya (), is an Indian religion or philosophical tradition based on teachings attributed to the Buddha. It originated in northern India as a -movement in the 5th century BCE, and ...
and
Hinduism
Hinduism () is an Indian religion or '' dharma'', a religious and universal order or way of life by which followers abide. As a religion, it is the world's third-largest, with over 1.2–1.35 billion followers, or 15–16% of the global p ...
refer to the
chakra of the navel as the
manipura. In
qigong, the navel is seen as the main energy centre, or
dantian. In
Hinduism
Hinduism () is an Indian religion or '' dharma'', a religious and universal order or way of life by which followers abide. As a religion, it is the world's third-largest, with over 1.2–1.35 billion followers, or 15–16% of the global p ...
, the
Kundalini energy is sometimes described as being located at the navel.
File:Stylish navel piercing.jpg, A pierced navel.
File:Belly Dance (4252337733).jpg, Belly dancers
File:Elia Markopoulos at an NECW event in Malden, MA 1-13-12.jpg, A man wearing a crop top
File:Yosakoi Performers at Kochi Yosakoi 2006 17.jpg, Japanese women performing a traditional Japanese dance ' in navel-exposing attire in the ' 2006 at Kōchi
See also
*
Alvinolagnia
A belly fetish (also known as a stomach fetish, or alvinolagnia) is a partialism in which an individual is sexually attracted to the midriff or belly.
Belly fetish model Helena Strong stated, "People admire my belly. The only thing I expose is m ...
*
Navel fetishism
*
Navel piercing
*
Omphalos
*
Umbilical microbiome
*
Omphaloskepsis
References
Further reading
*
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*
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*
External links
*
{{Authority control
Abdomen