PMN (Polymorphonuclear Neutrophil) Infiltration
Definition
The first histological cellular marker of antemortem vital reaction. Begins emigrating from wound-margin venules within 1-2 hours of injury; histologically visible at 6-12 hours; dense band present at 12-24 hours.
- Significance
- Earliest histological marker of vital reaction
- Emigration onset
- 1 to 2 hours post-injury
- Visible microscopically
- 6 to 12 hours
- Dense band forms
- 12 to 24 hours
Common questions
Why does the neutrophil timeline matter for antemortem versus post-mortem distinction?+
A wound inflicted after death cannot mount an inflammatory response, so any neutrophil emigration or banding at the wound margin confirms the injury occurred while circulation was intact, and the stage of the response helps bracket a survival interval.
What limits how precisely PMN infiltration can date a wound?+
The timeline is an average derived from case series and varies with the victim's age, health, ambient temperature, and wound type, so it gives a plausible survival window rather than an exact time, and it is normally read alongside other vital-reaction markers.
Related terms
- Agonal Period
- The final period of physiological life between loss of consciousness and cardiac arrest. Injuries inflicted in this period are legally antemortem but...
- Fibronectin
- Glycoprotein deposited in wound matrix within 12-24 hours of antemortem injury. Detectable by immunostaining; serves as an intermediate-stage vital-reaction marker when PMN...
- Histamine Vital-Reaction Marker
- Biochemical indicator released from mast cells within minutes of tissue injury. A 50% or greater histamine elevation at the wound margin versus...
- Perimortem Window
- The brief interval before and immediately after cardiac arrest in which injuries may be inflicted during life but produce absent or minimal...
- Vital Reaction
- The suite of physiological responses to tissue injury that require a functioning cardiovascular and cellular metabolism to occur: haemorrhage, neutrophil infiltration, vasoactive...