Cosmos
From the Cosmos newsroom.
After death, the human body undergoes a series of natural processes as it begins to decompose.
Somatic death occurs when all vital signs irreversibly stop, namely breathing, heartbeat and brain function. Immediately after death, all the muscles in the body relax, a state known as primary relaxation.
Within minutes, the body starts to cool down from its normal temperature of about 37°C to the surrounding temperature. This process is called algor mortis, Latin for “cold death”. Before the body acclimates, forensic scientists can use body temperature to estimate time since death.
Decomposition starts almost immediately after death with autolysis or “self-breaking”. As the body’s cells break down, they release enzymes that start self-digestion.
As soon as 3 to 4 hours after death, rigor mortis sets in. This is caused by calcium leaking into the muscle cells, causing them to contract. In life, the energy molecule ATP is used to relax muscles, but ATP is depleted in death.
Rigor mortis is noticeable in smaller muscles first, such as the eyelids, hands and face. It impacts the larger muscles within 12 hours, stiffening the entire body. This phase typically lasts for until 36 hours before decomposition begins to break down the muscle tissue. Muscle decomposition leads to secondary relaxation.
Meanwhile, putrefaction involves the decomposition of body tissues by bacteria and microorganisms. Starting in the gut, these microorganisms release gases such as methane, hydrogen sulfide and sulfur dioxide. These gases cause the body to bloat. This stage is associated with a strong odour due to cadaverine and putrescine, compounds produced during the breakdown of amino acids.
Several factors influence the rate of decomposition, including temperature, humidity, and the presence of insects. Insects, particularly blowflies, play a significant role in decomposition by laying eggs in the body. These then hatch into maggots that consume the soft tissues, including muscles, organs and skin.
In general, soft tissues are consumed rapidly. Harder tissues like bones and teeth can last for years or even centuries, depending on environmental conditions.
Death is a natural part of life. The process of decomposition returns elements and energy back into the ecosystem. Cosmos covers the science of everything including death:
- Why you should consider donating your body to science
- What should happen to your healthcare data after death?
- Podcast: Environmentally friendly alternatives for burial
*This article was generated by our custom AI service. Our service was built to focus on our archive of more than 15,000 factually correct science news stories and features. It also uses Open AI to help create the content. All generated content is fact checked by a trained science communicator and edited by our publishing team.
