Stages of death
The stages of death of a human being have medical, biochemical and legal aspects. The term taphonomy from palaeontology applies to the fate of all kinds of remains of organisms, with forensic taphonomy concerned for remains of the human body.
Clinical signs and stages of deathEdit
Signs of death or strong indications that a warm-blooded animal is no longer alive are:
Until the middle of the 20th century, the definition of and criteria for death, medically speaking, could be put concisely:
Sufficient destruction of the brain, including the brainstem, ensured respiratory failure leading quickly to terminal cardiac arrest. Conversely, prolonged cardiopulmonary failure inevitably led to total, irreversible loss of brain function.
The definition of legal death, and its formal documentation in a death certificate, vary according to the jurisdiction. The certification applies to somatic death, corresponding to death of the person, which has varying definitions. Death at the level of cells, called molecular death, follows a matter of hours later. These distinctions, and the independence of physicians certifying legal death, are significant in organ procurement.
The stages that follow shortly after death are:
- Pallor mortis, paleness which happens in the 15–120 minutes after death
- Algor mortis, the reduction in body temperature following death. This is generally a steady decline until matching ambient temperature
- Rigor mortis, the limbs of the corpse become stiff (Latin rigor) and difficult to move or manipulate
- Livor mortis, or dependent lividity, a settling of the blood in the lower (dependent) portion of the body
- Putrefaction, the beginning signs of decomposition
Of these, with obvious mortal damage to the body, the textbook conclusive signs of death clear to a lay person are: rigor mortis, livor mortis, and putrefaction.
The cardinal signs of death may refer to the ending of breathing, heartbeat and circulation, or to algor mortis, livor mortis and rigor mortis; the adoption of brain death as a definition has lessened the centrality of these signs. In a clearer contemporary terminology, algor mortis, livor mortis and rigor mortis are called "early postmortem" changes, in distinction from the "immediate postmortem" changes associated with the cessation of bodily functions, as indicated by vital signs. With an ophthalmoscope, changes to the blood in the retina are quickly visible.
Those stages are followed, in taphonomy, by
- Decomposition, the reduction into simpler forms of matter, accompanied by a strong, unpleasant odor.
- Skeletonization, the end of decomposition, where all soft tissues have decomposed, leaving only the skeleton.
- Fossilization, the natural preservation of the skeletal remains formed over a very long period. This stage may not occur, depending on the circumstances and the conditions of the surrounding environment.
This section needs additional citations for verification. (September 2020) (Learn how and when to remove this template message)
Descriptions of decomposition may refer to a five-stage process:
- Stage 1: Initial decay: Bacteria located mainly in the lower intestine begin decomposition, giving a greenish color to the lower abdomen.
- Stage 2: Putrefaction: Bacteria grow throughout the body, releasing gases, including cadaverine, which in turn bloat the body and cause an unpleasant odor.
- Stage 3: Black putrefaction: This stage brings further discoloration to the body. The gases from bacterial decay begin to escape, causing a strong odor.
- Stage 4: Butyric fermentation: The internal organs liquefy and the body begins to dry out.
- Stage 5: Mummification: This is the slowest of the five stages. In a hot, dry climate the body may dehydrate, inhibiting bacterial decay; the skin dries to a dark leathery appearance.
- Sorg, Marcella H.; Haglund, William D. (13 December 1996). Forensic Taphonomy: The Postmortem Fate of Human Remains. CRC Press. p. 13. ISBN 978-1-4398-2192-3.
- "The Definition of Death" entry by David DeGrazia in the Stanford Encyclopedia of Philosophy, August 9, 2016
- Bardale, Rajesh (October 2011). Principles of Forensic Medicine & Toxicology. Wife Goes On. p. 133. ISBN 978-93-5025-493-6.
- Peitzman, Andrew B.; Rhodes, Michael; Schwab, C. William (2008). The Trauma Manual: Trauma and Acute Care Surgery. Lippincott Williams & Wilkins. p. 415. ISBN 978-0-7817-6275-5.
- Pollak, Andrew N.; Browner, Bruce D.; Surgeons, American Academy of Orthopaedic (2002). Emergency Care and Transportation of the Sick and Injured. Jones & Bartlett Learning. p. 19. ISBN 978-0-7637-2046-9.
- Fox, Renée C. (1981). "The Sting of Death in American Society". Social Service Review. 55 (1): 47–48. doi:10.1086/643890. ISSN 0037-7961. JSTOR 30011444. PMID 10250829.
- Prahlow, Joseph A. (10 March 2010). Forensic Pathology for Police, Death Investigators, Attorneys, and Forensic Scientists. Springer Science & Business Media. p. 163. ISBN 978-1-59745-404-9.
- Almulhim, Abdulaziz M.; Menezes, Ritesh G. (2020). "Evaluation of Postmortem Changes". StatPearls. StatPearls Publishing. PMID 32119351.
- Saukko, Pekka; Knight, Bernard (4 November 2015). Knight's Forensic Pathology. CRC Press. p. 57. ISBN 978-1-4441-6508-1.