- Vernix caseosa
Vernix, also known as Vernix caseosa, is the waxy or "cheesy" white substance found coating the
skin ofnewborn humans. It is secreted by the fetus'ssebaceous gland s "in utero," and is hypothesized to have antibacterial properties. "Vernix" is the Latin word for "varnish." The vernix, "varnishes" the baby. "Caseosa" is "cheesy" in LatinVernix is composed of
sebum (the oil of the skin) and cells that have sloughed off the fetus' skin. A substantial percentage of the dry weight of vernix (12%) is composed of branched chain fatty acid containing lipids. [http://www.ncbi.nlm.nih.gov/pubmed/18614964?dopt=Abstract]The vernix is secreted by the
sebaceous gland s around the 20th week ofgestation , but the amount of vernix decreases toward the end ofgestation . It has been hypothesised that it protects the baby's skin fromdehydration in the womb. Without the vernix, the baby would have very wrinkled skin from constant exposure to the wateryamniotic fluid Fact|date=August 2008 .Vernix is sometimes offered as supporting evidence for the
Aquatic Ape Hypothesis (AAH/AAT) that the reason for the divergence between thehominid s and their ape-like relatives was due to a long semi-aquatic phase of history. No other landmammal , including the apes, produces vernix-coated neonates; in contrast, some sea mammals, including theharbour seal , do ( [http://www.bbc.co.uk/radio4/science/scarsofevolution.shtml Prog. 2 of BBC series on AAH/AAT] quoting Professor Don Bowen of Nova Scotia's Department of Fisheries and Oceans Marine Mammal Division).External links
* [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=search&db=PubMed&term=Vernix+Caseosa PubMed articles on Vernix caseosa]
* [http://www.bbc.co.uk/radio4/science/scarsofevolution.shtml Scars of Evolution] (online series of two BBC radio programmes about AAH/AAT)
*http://www.babyzone.com/glossary/default.asp?termid=522 (Pregnancy Glossary)
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