When a person dies, their organs go through various processes based on whether the death is natural or from organ donation. Understanding what happens to organs after death provides insight into deceased donation as well as natural decay.
What happens to organs after natural death?
When a person dies of natural causes, the organs begin to deteriorate and decompose. This is a natural part of the dying process as the organs no longer receive oxygen and nutrients. Here is a brief overview of what happens to the major organs:
Brain
The brain is one of the first organs to decompose after death. Within minutes after the heart stops beating, the brain cells begin dying, leading to tissue decomposition. Autolysis, the body’s natural self-destruction process, liquefies the brain over time. The brain decomposes rapidly compared to other organs.
Lungs
The lungs collapse and deflate shortly after death since the respiratory system no longer functions. Enzymes start digesting the tissues. The lungs may also congest with blood if the person died from lung-related illness like pneumonia. As the lungs decompose, the tissues liquefy and release decompositional fluids.
Heart
The heart stops beating upon death, entering cardiac arrest. Heart cells die from lack of oxygenated blood supply. Calcium ions build up in the muscles causing rigidity in a process called rigor mortis. The heart muscles will eventually decompose as autolysis occurs.
Liver
The liver has high levels of enzymes and moisture, so it breaks down rapidly after death. Hepatocyte cells die off, releasing enzymes that autolyze the tissues. The liver reduces in size and becomes discolored during decomposition.
Kidneys
The kidneys shut down upon death, no longer producing urine. With no blood supply, the kidney tissues begin dying. Decompositional fluids and broken down cellular material accumulate in the kidneys during autolysis. Over time the kidneys shrivel up significantly.
Pancreas
Digestive enzymes like amylase and lipase are released from the deteriorating pancreas after death. These enzymes start “digesting” the pancreas tissues through autolysis. The pancreas becomes soft and discolored as the enzymes break down cell membranes and connective tissues.
Intestines
The gastrointestinal system also starts decomposing from autolysis after death. Digestive enzymes eat away at the intestinal linings. Gas-forming bacteria within the intestines also accelerate decomposition. The intestines collapse as tissues break down and release gas and decompositional fluids.
What happens to organs in organ donation?
Organ donation follows a different process for organ recovery and preservation. Here is what happens to organs during transplantation:
Declaring Brain Death
Patients are declared brain dead before organ donation occurs. Brain death means the brain has irreversibly lost all function while the heart is still beating via life support. A series of examinations confirms no brain activity.
Keeping Organs Viable
After brain death, the donor’s body is kept alive by medical interventions like ventilation and fluids. This maintains oxygen and nutrient supply to preserve the organs.
Blood and Tissue Testing
Donor blood is sampled and tissue-typed to determine immunologic compatibility with potential recipients. Infectious disease testing also takes place.
Matching Organs to Recipients
National organ procurement organizations match donors to transplant candidates based on factors like blood type, tissue type, severity of illness, and time spent on the waiting list.
Harvesting Organs
The donor’s organs are carefully surgically removed in an operating room by trained medical teams. Each organ is individually excised with precision to avoid damage.
Preserving and Transporting
Organs are flushed with and stored in cold sterile preservation solutions to minimize cell death. They are rushed in cooled containers to minimize warm ischemia time.
Transplanting Organs
The recipient undergoes surgery to have the donor organ transplanted. It is reconnected to the recipient’s blood vessels and functions restored.
Recovery
The recipient stays in the hospital for monitoring and recovery as the transplanted organ integrates with the body.
What factors affect decomposition of organs?
Many intrinsic and extrinsic factors influence how quickly organs decompose after death:
Temperature
Higher ambient temperature speeds up chemical reactions involved in decay. Heat speeds up autolysis and bacterial growth. Body cooling slows these processes down.
Moisture
A moist environment encourages bacterial and fungal growth that aids decomposition. Dry conditions slow the process like mummification.
Oxygen Availability
Aerobic bacteria thrive with oxygen while anaerobic bacteria dominate without it. More oxygen exposure increases the breakdown of organs and tissues after death.
Trauma
Antemortem wounds and trauma to organs allow earlier access for bacteria and accelerated decomposition. Hemorrhage and ruptured organs decompose quicker.
Cause of Death
The pathology of the cause of death affects rate of decay. Lingering illnesses pre-death can lead to faster autolysis.
Body Size and Weight
Smaller organs with more surface area decompose faster. Obese individuals decay slower than slender bodies.
Clothing and Coverings
Natural vs synthetic fabrics make a difference. Tight coverings retain heat and moisture, supporting decomposition.
Stages of organ decomposition
Forensic anthropologists describe stages of organ decomposition after death:
Fresh Stage
Initial stage with no visible signs of decomposition. Organs maintain their natural color and texture.
Discoloration Stage
Blood pooling leads to purple discoloration of organs. Skin takes on a greenish tinge. Organs start losing their firmness.
Bloat Stage
Anaerobic bacteria generate gases like hydrogen sulfide, methane, and carbon dioxide that accumulate in organs and tissues, causing them to swell. Organs become more discolored and softened.
Active Decay Stage
Intensified autolysis liquefies tissues into decomposition fluids. Organs shrink and collapse. Color changes to black or brown.
Skeletonization Stage
Residual skin, cartilage, and organs fully decompose leaving just the skeleton and bone. Complete deterioration of all soft tissues.
Changes to specific organs during decomposition
The visual changes that occur in individual organs during decay include:
Brain
- Softens into a liquid mass
- Skull bones may split from pressure
- Leaking decay fluid stains
- Reduced brain volume
- Strong odor
Lungs
- Deflation and flattened look
- Discoloration and congestion
- Liquefaction of tissues
- Strong gaseous odor
Liver
- Softening and flattening
- Greenish-black discoloration
- Enlarged in early stages
- Shrinks and hardens over time
- Strong enzymatic odor
Heart
- Flaccid and softened
- Greenish-black staining
- Tissue autolysis into dark fluids
- Strong odor from decomp fluids
- Pericardium rupture
Kidneys
- Soften and flatten out
- Greenish-black discoloration
- Accumulation of dark decomposition fluid
- Shrinkage over time
- Pungent odor
Pancreas
- Autodigestion by enzymes
- Liquidation of tissues
- Flattened and softened
- Discoloration from pink to black
- Strong chemical odor
Spleen
- Softened texture
- Purple to black color
- Swollen in early stages
- Shrinks over time
- Pungent odor
Intestines
- Darkened mucosa
- Gas buildup and enlargement
- Tissue liquefaction
- Rupture of bowel
- Strong fecal odor
Factors that preserve organs after death
While most organs quickly decompose, some environmental factors slow down deterioration:
- Cold environments – Frigid conditions freeze organs and slow enzyme activity and bacteria growth.
- Dry environments – Lack of moisture prevents bacterial and fungal growth.
- Anaerobic conditions – No oxygen inhibits aerobic decomposition.
- Mummification – Natural or artificial drying preserves organs.
- Embalming – Chemicals like formaldehyde slow down decay.
- Protective coverings – Tight wrappings seal out air, moisture and soil organisms.
Importance of understanding organ decomposition
Comprehending the process of organ decomposition has value in fields like:
- Forensic science – Helps determine time since death in autopsies and investigations.
- Funeral services – Guides embalming and restorative treatments before interment.
- Research facilities – Human tissue decomposition studies advance science and medicine.
- Legal medicine – Establishes organ viability and characteristics in potential crimes.
- Transplant medicine – Supports optimizing organ preservation and transplantation.
- Emergency medicine – Saves lives through rapid organ procurement procedures.
Conclusion
While organ decomposition begins rapidly after death, many factors influence the rate of deterioration. Understanding the stages and processes of decay provides insight into organ donation procedures as well as natural disintegration. Comprehending how organs break down and preserve also has importance in forensic, funeral, and transplant services.