How does modern embalming replace blood with preservative fluid?

In modern embalming, the process of replacing blood with preservative fluid is primarily achieved through arterial injection. Embalmers drain blood from one of the veins while simultaneously injecting a preservative fluid—typically based on Formalin, a solution of formaldehyde in water—into one of the main arteries.1

Additionally, to treat the internal organs, cavity fluid is removed using a long, hollow needle known as a trocar. This is replaced with a preservative mixture consisting of Formalin, alcohols, emulsifiers, and other substances designed to prevent the body from shriveling or discoloring. The primary goal of these procedures is to provide a lifelike appearance for mourners during the viewing period, rather than to achieve permanent preservation.1