Hematogenous Dissemination
Definition
Spread of a substance via the bloodstream. In the diatom test, diatoms aspirated into the lungs during ante-mortem drowning enter pulmonary capillaries and are carried by blood flow to distant organs. It is the mechanism that distinguishes vital (living) water aspiration from post-mortem surface deposition.
- Definition
- Spread of a substance via the bloodstream
- Forensic context
- Diatom test in drowning investigation
- Mechanism
- Diatoms enter pulmonary capillaries, carried onward
- Significance
- Distinguishes ante-mortem from post-mortem submersion
Common questions
Why is finding diatoms in organs like bone marrow more significant than finding them in the lungs alone?+
Diatoms can passively enter the lungs even after death simply from submersion, but reaching distant organs such as bone marrow requires active circulation, meaning the heart was still beating at the time of aspiration, supporting ante-mortem drowning.
What can cause a false negative in hematogenous diatom dissemination testing?+
Very rapid death after aspiration, a low diatom concentration in the water, or decomposition affecting circulatory integrity can all limit how many diatoms reach distant organs, so a negative result does not rule out drowning on its own.
Related terms
- Acid Digestion
- A laboratory preparation step in which concentrated mineral acids are used to destroy all organic tissue in a sample, leaving only acid-resistant...
- Ante-Mortem Drowning
- Drowning that occurs while the victim is still alive and the cardiopulmonary system is functioning. Active breathing and circulation are prerequisites for...
- Bone Marrow
- The fatty and haematopoietic tissue inside long bones such as the femur and tibia. Because it is enclosed in dense cortical bone,...
- Control Sample
- A water sample collected from the suspected drowning environment at or shortly after the time of body recovery. Its diatom assemblage is...
- Post-Mortem Immersion
- Placement of a body in water after death. Passive water entry into the upper airways and body cavities can carry diatoms into...