Death, Changes after Death
&
Estimation of PM Interval
Death
Thanatology (thanatos-death + logos)�
Types of death
Molecular or cellular death
Brain Death
Three Cardinal Findings
Brain death
Brain Death (Cont)
Gordon’s Classification of Death
Modes of Death
Suspended Animation
Signs Of Death/ Changes after Death
Immediate Signs of Death
Stoppage of Circulation/ Respiration
Functions of the Brain
Early Changes After Death
Changes in Eye
Taches noires
Cooling of the Body�(Algor mortis)
Algor mortis
Post Mortem Caloricity
Factors Modifying the Algor mortis
Post-Mortem Lividity
Fixation of lividity
PM Staining (Cont.)
Difference Between Lividity & Bruise
Rigor Mortis
Cadaveric Rigidity
Mechanism of appearance
Development of Rigor
Progression & Disappearance
Factors Affecting Duration
Duration (Cont.)
Early Onset of Rigor | Late onset of Rigor |
Exhaustive wasting diseases- Cholera, Typhoid, Tuberculosis, Cancer | Asphyxial death, CO poisoning |
Violent death like cut-throat, electrocution, firearm, lightening injuries | Haemorrhage |
Poisoning by strychnine, organophosphate, insulin, KCN | Cold, refrigerated cadavers |
Fatigue, Exhaustion, & Heat Stroke | Paralysed muscles, Pneumonia |
Differences b/w Primary & secondary relaxation of muscles
Points | Primary relaxation | Secondary relaxation |
Time of occurrence | Immediately after death | After rigor mortis passes off and decomposition occurs. |
Death of muscle tissue | Has not occurred | Molecular death of muscles has occurred. |
Response to stimuli | Responds | Does not respond. |
other external findings | Body may still be warm | Signs of decomposition are there |
body temperature | closer to normal of 98.4 F | Low body temperature |
ML Aspect of Rigor Mortis
Cadaveric Spasm
Cadaveric Spasm
Diffs b/w Rigor mortis & Cadaveric spasm
Points | Rigor Mortis | Cadeveric Spasm | |
Onset | Within 1 or 2 hours after death | Instantaneous with death. | |
Muscles involved | All muscles of the body are affected gradually | Selected voluntary muscles which were in a state of contraction at the time of death. | |
Primary flaccidity | Precedes R.M. | Does not come in the affected muscles | |
Intensity of rigidity / contraction | Comparatively moderate | Comparatively very strong |
Death of muscle | Molecular death of muscles occur | No molecular death of the muscles |
Duration of stay | About 12-18 hours | A few hours , until replaced by rigor mortis. |
Predisposing factor | Nil. It is a normal change after death seen in all cadavers. | Excitement , fear, fatigue, exhaustion along with contraction of muscles during death. |
Body temperature | Low | Comparatively high |
Muscle reaction | Acidic | Alkaline |
Reaction to stimulus | Does not respond | Responds |
Mechanism of formation | Break down of ATP below critical level | Not known exactly. |
Medicolegal importance | Mostly helps to know the time of death | Speaks sometimes about cause of death & sometime about the nature of the death (whether suicidal, homicidal etc.) |
Heat Stiffening
Pugilistic Attitude
Diff. b/w rigor mortis & heat stiffening
Points | Rigor Mortis | Heat stiffening |
Degree of stiffness | Moderate | High |
Time of formation | 1 or 2 to 4 hours after death | May be antemortem or postmortem. Formed due to application of heat. |
Role of heat | Atmospheric high temperature enhances the process | Occurs at a temperature above 65 degree Celsius |
Mechanism of formation | Due to breakdown of ATP of muscles | Due to heat coagulation of muscle protein. |
External appearance | Nothing specific | Signs of exposure to heat will be there e.g. burning m blackening, blister formation etc. |
Cold Stiffening
Gas Stiffening
Secondary Relaxation of Muscles
Decomposition
Stages of Decomposition
Decomposition
ORGANISMS CAUSING DECOMPOSITION
Fungal colonization of human cadaver
Progress of Putrefaction
Internal Decomposition
Progress of Putrefaction
Colliquative putrefaction : between 5-10 days
Internal Factors Affecting Rate
Adipocere (Saponification)
Adipocere (Saponification) Cont.
post mortem interval is at least weeks and probably several months.
Mummification
Mummification
Maceration
Post-mortem Interval
CORPORAL EVIDENCE | ENVIRONMENTAL & ASSOCIATED EVIDENCE | ANAMNESTIC EVIDENCE |
Stage ofchanges after death:- cooling, lividity decomposition. | Uncollected mail/newspapers | Usual activities |
soot in airway (fire/smoke inhalation) | Lights on or off | Walking & sleeping patterns |
Evidence if medical conditions | Alarm clock set | Eating habits, times, types of food |
Alcohol/drug levels | Food on stove/in refrigerator | Appointments |
Beard/nails/hair | Type of clothing day/night | Answered/unanswered correspondences |
Estimation of PM Interval
METHOD TYPE | INDICATOR |
Rate Method | Rate of drying or discoloration of blood pools |
Rate Method | Rigor Mortis |
Rate Method | PM Lividity |
Rate Method | Cooling of body |
Rate Method | Decomposition |
Rate Method | Flora (plants) around body |
Rate Method | Fauna (insects) around body |
Concurrence Method | Time of last known meal |
Concurrence Method | Stopping of watch (due to trauma/damage) |
Concurrence Method | Making or receiving call on cell, misscall |