THANATOLOGY

thanatos- death; logos- science

Assoc. Prof. Beatrice Ioan

MD, PhD, MA

Death

• Irreversible loss of the properties of the living matter.

• Cessation of life in a previously viable organism

• Process - different rates of cellular death - internal organs have different functions with different cellular metabolic processes which cease to function at different rates

Stages of death

1. Agony (vita minima)- irreversible stage between life and death- mixture of vital and thanatologic processes

• Decreased activity of cortical neurons • Bulbar centers are no longer controlled by

cortical and sub-cortical centers- functioning of the organism is no longer unitary

Agony

- Progressive disappearance of psychical functions- psychical chaos

- Decreased contact with the environment

- Complete immobility

- Progressive disappearance of senses

- Diminished vegetative functions

AgonyClassificationI. According to duration:• absence of agony- death occurs very rapidly • short agony (seconds, minutes)• long agony (hours)

II. According to the psychical condition:• conscious agony- no changes of consciousness;• unconscious agony; • alternation of conscious and delirious periods

Importance:- Validity of the documents signed during agony

Stages of death

2. Clinical death- Short interval (about 5-10 minutes) - Cardiac activity and respiration are absent- Cortical neurons still function - The patient can be reanimated by medical means

3. False death - Very diminished respiration and heart activity- Cannot be detected by ordinary means- Loss of consciousness

Stages of death4. Biological death (real death)- irreversible - characterized by cessation of cellular metabolism and structural changes of cells

Stages:a. Somatic (systemic) death- complete and irreversible cessation of vital functions- life ceases in the body but still persists in some of its parts

b. Molecular (cellular) death - death of the tissues and cells individually - due to anoxia- different tissues die at different rates

Signs Of Death I. Diagnosis of death in clinics- immediate signs of death- Cerebral death- Absence of cardiac activity and circulation- Absence of respiration

Diagnosis of death in the autopsy roomII. Early signs of death- Postmortem lividity (hypostasis)- Rigor mortis- Cooling- Dehydration- Autolysis

III. Late signs of death- Putrefaction (postmortem decomposition)- Conservatory processes

Postmortem lividity (hypostasis)

Mechanism• the circulation ceases

↓• accumulation and stagnation of blood in the capillaries

and small veins of the skin and organs ↓

• the blood is pulled by gravity in the lowest areas of the body

Aspect• discoloration of the skin in lowest parts of the body• red-bluish/ compression areas

Postmortem lividity (hypostasis)

Stages:Hypostasis- 10-12 hours Stasis- 18-20 hours Imbibition- after 20-24 hours

Differentiation of the postmortem lividity from bruise

Forensic relevance- Diagnosis of death- Position of the body- Postmortem interval- Cause of death

Rigor mortis (cadaveric rigidity)

Mechanism• Decrease/ disappearance of ATP in the muscles - ATP concentration

fails to 85 per cent of normal

Factors affecting the timing of rigor mortis- temperature of the environment- physical activity before death- cause of death

Stages- Nisten ruleInstallation- 3-6 hours Generalization- 24 hours Disappearance- 24-36 hours

Forensic importance- Diagnosis of death- Position of the body- Postmortem interval- Cause of death

Postmortem cooling (Algor mortis)

Mechanism- Failure of heat production and thermo-regulation → the body is loosing heat

(conduction, convection, radiation) → temperature of the body decreases progressively → equilibrium with the environmental temperature

Factors affecting postmortem coolingEnvironmental temperature Air moving and humidityClothing and coveringsPostureSurroundingsDimensions of the body Hemorrhage

Particular: postmortem caloricity

18 degrees Celsius - 1 degree Celsius per hour

Forensic importance- diagnosis of death, postmortem interval

Dehydration

Mechanism• Cessation of circulation and metabolic

processes → the body looses water

Aspects - pergamentation - finger pads’ skin and lips-wrinkled - opaque cornea - soft eyes

Autolysis auto- self; lysis- destruction

• enzymes released from the cells soften and liquefy the tissues of the body

• internal examination

• organs with a high content of enzymes (e.g. pancreas, stomach)

• prepares the field for putrefaction • can be prevented by freezing the body/tissues

Putrefaction (postmortem decomposition)

• The last stage in the resolution of the body from organic to inorganic state → skeleton

Bacterial process

Factors affecting putrefaction - environmental temperature - concentration of oxygen - concentration of water (brain)- age- old age- cause of death

Putrefaction (postmortem decomposition)

Aspects- green spot of putrefaction- 2-3 days

- all the skin - dark green or almost black

- gases of putrefaction- increased volume

- marbling

Particular situation* New born

Forensic entomology

• Study of the insects that infest the corpses

• Flies lay their eggs on the corpse- opened wounds and moist sheltered natural orifices- 18/36 hours (high temperature)

• Maggots or larvae - 24 hours -inside the body- destroy soft tissues

• Pupae - 4-5 days

• Adult flies - 3-5 days

7 series - 3 months→ 3-4 years

One species at one time on one body fragment- different nutrients

Conservatory processes

Natural processes which, prevent putrefaction and preserve the corpses

I. Mummification Very rapid dehydration - warm climate + good ventilation - Bacterial activity stops- high temperature - 3-12 months after death

Aspect Skin- dry, shrunken, leathery, brown to dark skin adhering closely to

the bones Odorless Preserved features Reduced body volumeInternal organs - dried mass

Conservatory processes

II. Saponification (Adipocere)

- Fatty tissues are hydrolyzed - saturated fatty acids (stearic, palmitic acids) → calcium soaps

- 3-12 months

Aspect - yellowish- white greasy wax like substance- rancid smell - floats on water- can be easily cut- burns - yellow flame

Factors affecting saponification• Environment- moisture; warm temperature; absence of air• Lecithinase from Clostridium Welchii

Conservatory processes

III. Lignification

Environment with great concentration of tanic and humic acid (swamps, mines, volcanic lava)

Aspect• brownish, hard skin• soft bones (loosing of calcium);• good preservation for a long interval

Tolund Man- Denmark

Conservatory processes

IV. Refrigeration

Exposure of the corpse to low temperature

Aspect• whole body is stiffen;• perfect preservation for a long period of time;• when the body is bring into an warm

environment putrefaction develops rapidly

Forensic Autopsy Mandatory in the following situations (Criminal Law):

• Violent death

• Sudden death

• Suspect death

• Medical malpractice allegation

• Corpses with unknown identity

Rules:

• performed in the base of the order of juridical authority

• complete