The sight of a tongue protruding from the mouth of a deceased individual can be a disquieting observation. While unsettling, this phenomenon is a natural outcome of several post-mortem processes that affect the human body. It does not necessarily indicate trauma or a specific cause of death, but rather reflects the complex physiological changes that occur after life ceases.
The Role of Muscle Relaxation and Rigor Mortis
Immediately following death, all muscles, including those of the jaw and tongue, undergo complete relaxation, known as primary flaccidity. When jaw muscles relax, the jaw can drop open, causing the tongue to lose muscular support and shift position within the oral cavity.
Following this initial relaxation, rigor mortis begins, typically within two to six hours after death. This process involves the stiffening of muscles due to chemical changes, specifically the depletion of adenosine triphosphate (ATP) which is necessary for muscle relaxation. If the mouth is already open and the tongue is partially extended during the onset of rigor mortis, the stiffening of tongue muscles can cause it to become fixed in a protruded position. Rigor mortis usually peaks around 12 hours and gradually dissipates after 24 to 36 hours as muscle tissues begin to break down.
Internal Pressure from Decomposition
As the body enters the decomposition phase, internal biological processes contribute to changes in its appearance. Bacteria naturally present within the body begin to break down tissues. This microbial activity produces various gases.
The accumulation of these gases creates significant internal pressure within the body. This pressure can cause the abdomen and other body parts to bloat and swell, sometimes to twice their normal size. As this pressure builds, it can force fluids and soft tissues, including the tongue, outwards through natural orifices such as the mouth and nose.
Influence of Body Position
The position of a body after death can affect tongue visibility and protrusion. Gravity plays a role in the pooling and shifting of bodily fluids. If a deceased individual lies on their back, for instance, gravity can pull the jaw downwards, leading to the mouth opening.
With the mouth open, the tongue, lacking muscle tone, may fall backward into the oral cavity or, conversely, appear more prominent if already partially displaced. The orientation of the head and body can therefore influence how readily the tongue is observed, making it appear more or less protruded depending on the specific post-mortem posture.