Editing Embalming (section)

==For anatomy education==
{{more citations needed section|date=May 2023}}
A rather different process is used for [[cadaver]]s embalmed for dissection by medical professionals, students, and researchers. Here, the first priority is for long-term preservation, not presentation. As such, medical embalmers use anatomical wetting fluids that contain concentrated formaldehyde (37–40%, known as formalin) or [[glutaraldehyde]] and [[phenol]], and are made without dyes or perfumes. Many embalming chemical companies make specialized anatomical embalming fluids.

Anatomical embalming is performed into a closed circulatory system. The fluid is usually injected with an embalming machine into an artery under high pressure and flow, and allowed to swell and saturate the tissues.<ref name="Problem of Embalming" /> After the deceased is left to sit for a number of hours, the venous system is generally opened and the fluid allowed to drain out, although many anatomical embalmers do not use any drainage technique.

Anatomical embalmers may choose to use gravity-feed embalming, where the container dispensing the embalming fluid is elevated above the body's level, and fluid is slowly introduced over an extended time, sometimes as long as several days. Unlike standard arterial embalming, no drainage occurs, and the body distends extensively with fluid. The distension eventually reduces, often under extended (up to six months) refrigeration, leaving a fairly normal appearance. No separate cavity treatment of the internal organs is given. Anatomically embalmed cadavers have a typically uniform grey colouration, due both to the high formaldehyde concentration mixed with the blood and the lack of red colouration agents commonly added to standard, nonmedical, embalming fluids. Formaldehyde mixed with blood causes the grey discoloration also known as "formaldehyde grey" or "embalmer's grey".

A new embalming technique developed gradually since the 1960s by anatomist Walter Thiel at the Graz Anatomy Institute in Austria has been the subject of various academic papers, as the cadaver retains the body's natural color, texture and plasticity after the process.<ref>{{cite news|title = The living dead: new embalming method aids surgical training | url=https://www.bbc.com/news/health-22908661 | author=Phil Cain | date=15 June 2013 | publisher=BBC News | accessdate=7 June 2021}}</ref> The method uses 4-chloro-3-methylphenol and various salts for fixation, boric acid for disinfection, and ethylene glycol for the preservation of tissue plasticity.<ref>{{cite journal | author = Walter Thiel | journal = Annals of Anatomy | title = Ergänzung für die Konservierung ganzer Leichen nach W. Thiel | doi=10.1016/S0940-9602(02)80121-2 | pages=267–269 | year=2002 | volume=184 | issue=3| pmid = 12061344 }}</ref> Thiel embalmed cadavers are used in anatomical research, surgical and anaesthesia training, preoperative test procedures, [[CT scan|CT]] image quality studies.<ref>{{cite journal | title = Walter Thiel's Embalming Method. Review of Solutions and Applications in Different Fields of Biomedical Research | author1 = Nicolás Ernesto Ottone | author2 = Claudia A. Vargas | author3 = Ramón Fuentes | author4 = Mariano del Sol | journal = Int. J. Morphol. | volume = 34 | issue=4 | pages=1442–1454 | year=2016 | doi = 10.4067/S0717-95022016000400044 | url = https://scielo.conicyt.cl/pdf/ijmorphol/v34n4/art44.pdf}}</ref>