“It’s the basis of all medicine,” said Dr. Barbara A. Sampson, the first deputy chief medical examiner. From the mysteries of blood flow to the mechanics of the heart, the residents of the morgue have been whispering their secrets to the living since the place opened in 1918.

Dr. Sampson, bespectacled in a lab coat, was standing down the hallway from the coolers in the harshly lighted autopsy room, an antiseptic chamber with eight steel tables, a large supply of chemical preservatives and several shelves of Tupperware for the storage of vital organs. The smell was of formaldehyde with a lingering bitter undertone of cherries. It was the sort of stench that gets inside your nose and makes your head hurt, that seeps into the fabric of your clothes.

Autopsies are more or less performed the same way today as they were when Rudolph Virchow, a German physician, standardized the process in the 19th century. They can be crude at times, even brutal: Here, a metal soup ladle is used to scoop fluid from the bodies; a pair of hedge clippers, picked up at a hardware store, is employed to cut ribs.

Thousands of bodies pass through here each year, as many as a dozen on an ordinary day. They enter from a loading bay on 30th Street, reside on average for 24 hours, then are shipped back out to funeral homes or, if no one comes to claim them, to the city’s potter’s field, on Hart Island in the Bronx.

According to the City Charter, there are 13 reasons a body will be brought into the morgue, and you are lucky if none of them happens to you. Among them, there is death by violence, death by suicide and death by either accident or overdose. There is death in jail or from an injury related to employment. Then there is the catch-all death of anyone who dies while in “apparent good health.”