- Supernumerary body part
Supernumerary body parts are most commonly a
congenital disorder involving the growth of an additional part of thebody and a deviation from thebody plan . Body parts may be easily visible or hidden away, such as internal organs.Many additional body parts form by the same process as
conjoined twins : thezygote begins to split but fails to completely separate. This condition may also be a symptom of repeated occurrences of continuousinbreeding in a genetic line.pecific types of occurrence
Specific types of additional body parts include:
*Accessory breast – one or more additionalbreast sOnline Mendelian Inheritance in Man. " [http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=163700 Nipples, Supernumerary] ". Accessed10 July 2006 .]
*Cervical rib – an additionalrib [PatientPlus. " [http://www.patient.co.uk/showdoc/40001959/ Cervical ribs and thoracic outlet syndrome] ". Accessed10 July 2006 .]
*Diphallia - Having two penes.
*Hermaphroditism – having bothsex organ s [Grumbach, M.M., Conte, F.A., 1998. "Disorders of sex differentiation." in Williams Textbook of Endocrinology, eds. J.D. Wilson, D.W. Foster, H.M. Kronenberg, and P.R. Larsen, (Philadelphia: W B Saunders:1303-1425).] [Molnar, Sebastian,17 February ,2004 . [http://www.geocities.com/we_evolve/Plants/breeding_sys.html Plant Reproductive Systems] . Accessed10 July 2006 .]
*Hyperdontia – additional teeth [Derm Atlas. " [http://dermatlas.med.jhmi.edu/derm/IndexDisplay.cfm?ImageID=42691216 Image of hyperdontia] . Accessed10 July 2006 .]
*Polycephaly – an extrahead
*Polydactyly – additionalfinger s ortoe sPenn State Milton S. Hershey Medical Center A-Z. [http://www.hmc.psu.edu/healthinfo/pq/poly.htm Polydactyly and Syndactyly] . Accessed10 July 2006 .]
*Polymelia — an extra arm or leg.
*Polyorchidism – having three or moretesticle s [Wipro GE Healthcare. " [http://www.gehealthcare.com/inen/rad/us/technology/msupoly.html Polyorchidism] ". Accessed10 July 2006 .]
*Supernumerary kidney – a thirdkidney [Biology-Online.org. " [http://www.biology-online.org/dictionary/Supernumerary_kidney Supernumerary kidney] ". Accessed10 July 2006 .]
*Supernumerary nipple s – an additionalnipple
*Syndactyly – webbing between the fingers or toes
*Uterine Didelphys – (also Uterine Septum) have two vaginal canals and/or uteriRelated conditions and concepts
Vestigial structures are anatomical structures oforganism s in aspecies which are considered to have lost much or all of their original function throughevolution . These body parts can be classed as additional to the required functioning of the body. Inhuman anatomy thevermiform appendix is sometimes classed as a vestigial remnant.Prosthesis is an artificial extension that replaces a body part, andcybernetics is the study of computer technology in relation to organisms which can include replacement or additional body parts.Body integrity identity disorder (BIID) is a psychiatric disorder in which a person thinks that they have one or more additional limbs than they should, despite having two arms and two legs. People with this condition often wish toamputate what they see as additional body parts.A
phantom limb is the sensation that a missing limb is still attached to the body.A chimera is an animal or plant that has two or more different populations of genetically distinct cells that originated in different
zygote s that have merged; anatomical structures are typically mixed depending on which cells are prevalent in different body parts, for example plants can have two different types of flowers.A mosaic is a genetic anomaly similar in nature and effects to a chimera: genetically different populations of cells within one organism, originated from some propagated mutation of a single cell rather than from outside sources.
Popular culture
Additional body parts can be used to represent
monster s,mutant s and aliens. In many cases these additional body parts may be normal for the species but are only viewed as additional when compared to humans.Mythology
In
Hindu mythology additional limbs and heads are considered a sign of power.In
Greek mythology ,Artemis , the goddess of fertility, was sometimes represented as having numerous breasts. This was particularly notable in the cult of Artemis (Diana ) celebrated in the ancient city ofEphesus , in modernTurkey .ee also
*
Triple deities
*Polydactyl cat
*Unusually-shaped vegetable References
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