This document discusses various topics related to thanatology (the scientific study of death), including definitions of death, modes of death, brain death, suspended animation, and early post-mortem changes. It defines death as the permanent and irreversible termination of biological functions or complete and irreversible loss of brain functions. Death occurs in two stages - somatic/clinical death followed by cellular/molecular death. Early changes after death include body cooling, hypostasis (livor mortis), and rigor mortis. Brain death is characterized by the irreversible loss of all brain functions except those of the brainstem. Suspended animation is a temporary suspension of vital processes that in some cases is reversible.

1. Define Death.
Discuss Brain death
Discuss modes of death.
Discuss suspended Animation
Differentiate between Somatic Death and Cellular Death.
Discuss early changes after death
a. Body cooling b. Hypostasis c. Rigor mortis

2. ⦿ THANATOLOGY is the scientific study of Death phenomena &
practices relating to death.
⦿ Life depend upon integration of three vital system (tripod of life)
Death Definition
Permanent & irreversible termination of biological functions of an
organism.
Or complete & irreversible loss of brain functions followed by
cessation of heart & lungs functions and it called Somatic Death

3. Death occurs in two stages
⦿ Somatic systemic or clinical death.
⦿ Cellular or molecular death.

4. Somatic death:-
The complete & irreversible cessation of brain
Functions followed by stoppage of circulation & respiration.
Molecular death :-
After somatic death, tissue/cells die, it occurs in
piecemeal as nervous tissue die rapidly within minutes while
muscles
2– 3 hours. Molecular death is accompanied by early
changes after death– within 24HRs.

5. BRAIN DEATH
Vegetative state
When higher levels of cerebral activity are lost either from anoxia,
trauma or toxic insult, victim will exist in “vegetative state”.
In this state brain stem centers ensure breathing & cardiac activity,
victim remain in deep coma almost indefinitely for years may result in
complications of bedsores, chest infections& muscle contractures.
In this state victim is not considered dead.
In present environment, no one would consider a person dead, with
spontaneous breathing and whose heart was beating.

6. CONTT:-
With the advent of ventilator in medical technology, the circulation and
respiration can be maintained despite the loss of all brain functions,
brought the concept of brain death.
Brain death is the complete and irreversible loss of all brain
functions(CNS) except spinal cord.
Brain death infact means brainstem death.
The crucial point in determining brain death is the demonstration of
absence of all brainstem functions.

7. When cardio-pulmonary arrest occur, brain function ceases
within seconds, blood pressure collapse & consequent
cerebral ischemia, within minutes, lead to loss of brain
functions.
The indications are Three Cardinal Signs
1.Coma
2. Absence of brain stem reflexes
3.Apnea

8. INDICATIONS OF DEATHS
1.Coma or Unresponsiveness:- no motor response to painful stimuli
2. Absence of brainstem reflexes
a. Absent Papillary response to light (dilated pupils)
b.Ocular movement,No oculocerebral movements (Doll eye
phenomena)
c. Facial sensation & facial motor response:- no corneal reflex . No
jaw reflex.
d. Pharyngeal and tracheal reflex:- no gag reflex no cough reflex on
bronchial suction.
3. Apnea test. Complete loss of brainstem function.Loss of centrally
controlled breathing

9. Time – Interval between Somatic &
Molecular stages
Heart Survives For 60 minutes
Liver Survives for 15 minutes
Kidney Survives for 45minutes
Cornea Survives for 6-24 Hours
Blood Survives for 6 Hours
Bone Marrow Survives for 6 Hours

10. BRAINDEATH MEDICOLEGAL SIGNIFICANCE
1. Confirmation of death by doctors (uniform determinate)
2. Criminal proceeding, the injuries caused death not the doctor, switching off
machines.
3. Organ Donation & transplantation.
4. Religious issue disposal of dead body

11. SUSPENDED ANIMATION (APPARENT DEATH)
When vital processes of the body depressed to minimum compatible
with life but clinically perceived and body behave like a cadaver.
(Temporary suspension of heart beat & respiration – called Apparent
Death may persist from few seconds to several minutes).
Some recover from this state and others die.
Suspended animation occurs in:
Drowning, Electrocution, Heart stroke, New born, Cerebral concussion
After anesthesia, Poisoning (Sedatives Barbiturates Opiates), deep shock
Humans have the ability to acquire such state voluntarily and such
examples exist in Asia Sufi & Saints
This phenomena exist in animals during Hibernation

12. MODES OF DEATH
1. Coma:- Death from failure of brain functions
2. Syncope:- The death from failure of heart function
3. Asphyxia:- Death from failure of respiratory function

13. COMA
When Death is from brain functions failure & its irreversible damage to vital centers.
Causes
1. Raised intra cranial pressure.
2. Head injuries.
3. Diseases of brain/membranes.
4. Intoxication: - drug abuse or opiods & alcohol over dosage
Metabolic disorders ureamia, diabetes

14. SYNCOPE – NEUROCARDIOGENIC SYNCOPE
When death from heart failure as result of hypoperfusion & hypoxia of brain
causes.
1.Heart disease
2.Hemorrhage
3.Pathology of blood
4.Exhausting disease
5.Poisoning – Digitals Oleander, Aconite
6.Reflex cardiac arrest

15. ASPHXIA
Death from the failure of respiratory functions
Pathological condition
Pneumonia
Respiratory passage obstruction
Respiratory centers failure
Poisoning
Traumatic asphyxia

16. CHANGES AFTER DEATH
Divided into three groups
1.Immediate 2. Early 3. Late
Immediate signs –somatic death & appear Immediate signs
1. Insensibility & loss of EEG rhythm
2. Cessation of circulation
3. Cessation of respiration
4. Skin changes
5. Primary flaccidity
6. loss of reflexes

17. EARLY CHANGES AFTER DEATH
Cooling: Fall of body temperature
Hypostasis: Shifting of blood in vascular network
Rigor mortis: Postmortem flaccidity followed by postmortem rigidity
Ocular changes: Changes in eyeballs

18. MLI OF SOMATIC / MOLECULAR DEATH DIFFERENTIATION
Important for two reasons.
Disposal of dead body
Organ transplantation
Disposal of dead body :-Movements of limbs at time of burial prayer or
At moment of cremation – give doubt to premature disposal.
Organ transplantation:-Viability of transplantation organ decreases
sharply after somatic death.
Liver is taken within 15 min ,kidney within 45 min, Heart within hour.

19. COOLING OF BODY (ALGER – MORTIS)
In life, balance between heat production & heat loss. After death, heat
production stop & body loses heat by convection, conduction &
radiation, till the equilibrium achieved with surrounding temperature
Recording Body Temp
The progressive fall of body temperature recorded long-range chemical
thermometer (25cm) 0 – 50°c, inserted into rectum 8 – 10 cm
Before insertion swab taken in sexual activity left for 2 -3 minutes OR
auditory meatus or Nostrils or abdominal incision (slit) under liver.
Environment temperature is recorded & time noted, records made at
regular intervals of five minutes

20. BODY COOLING RATE
Normal body cools shortly after death except in serious illness when it cools even
before death due to circulation failure.
Temperature at time of death
fever - high temperature
collapse( lower temperature)
these temperature changes should be taken in account.
HOW HEAT IS LOST FROM BODY?
Heat loss from surface of body and reaches to the surface from the body interior, so
during this time it remain unchanged for short period. This phase is known
“Isothermic phase” There is no fall in rectal temperature for 45 minutes,
Afterward the cooling is uniform but related to the body temperature & its
surrounding

21. In tropical country like India/Pakistan average fall of body
temperature is 0.5 – 0.7°c per hour & environmental temperature is
achieved in 16 – 20 hours of death
Rough Formula to estimate time since death
Time since death= normal body temp minus rectal temp divided by
average fall of temp(0.6°c)
Time since death = 37.2°c – 28°c / .6 °c = 15 hours

22. POSTMORTEM CALORICITY.
There are certain conditions where body temperature is raised at the time
of death and it is known as “Postmortem caloricity.
1.Sunstroke
2.Tetanus
3.Asphyxia death
4.Strychnine poisoning
5.Acute bacterial or viral infection such as typhoid fever, septicemia,
6.Fat/air embolism deaths
7.Aspirin poisoning deaths
8.Hemorrhages into brain stem

23. BODY COOLING RATE IS MODIFIED
Age & condition of body:-Lean bodies & children cools rapidly due to large
surface area while fatty adult women cools slowly as fat is an insulator
Mode of death:In case of Sudden death of healthy individual,the body tend
to cool less rapidly while in cases of long lasting wasting or illness or
collapse, the body cool rapidly.
Surrounding temperature Air currents – well ventilated room than close
room .Cools rapidly in water – Clothed vs. naked body
Environment temperature :-Difference between body & environment
temperature

24. EYE CHANGES
Changes in cornea sclera and retina
CORNEA: - Clear, glistening and lost.Cornea become dry cloudy & opaque due to
failure in tears production. Light reflex and corneal reflex is lost.
Pupils – dilate at time of death & later constricted due to development of rigor mortis
Intraocular pressure – decreased tension & eyeballs fall into orbit
Taches Noires – appear on sclera about 3 hours after death if eyes remain open –
blackish brown discoloration on the exposed surface of sclera between eye lids
due to debris deposition .
Retinal changes – 3 hours become pale and optic disc gets yellow in 3 hrs ,
later segmentation in larger blood vessels (Cattle trucking and optic disc pale)

28. HYPOSTASIS
Definition :-Discoloration of skin & organs after death due to shifting of blood in
toneless and unsupported small blood vessels toward dependent parts of body
due to gravitational forces. Also known as Postmortem lividity or staining or
Hypostasis
The process START immediately after death and appears after 30 minutes to 2
hours,initially as scattered patches, gradually patches grow in size and color.
In 10-12 hours they unite to form extensive area of uniform discoloration.
Any pressure on body will prevent the filling of blood vessels that’s why Contact
flattening in areas in contact with surface of body is lying where toneless
capillaries are compressed & not filled with blood.
Thus lying on the back, there will be contact flattening on shoulders back,
buttocks and back of calves while in hanging -------------------

29. TIME SINCE DEATH GRAPH

33. HYPOSTASIS IN VISCERAL ORGANS:
Intestines:- Dependent loops of jejunum & ileum are discolored and
maybe confused with mesenteric infarction or strangulation.
Hypostasis is discontinuous, interrupted segments, often loops of pelvis
most affected.
Lungs:-Posterior surface edematous & discolored in Para-vertebral
gutters while anterior surface is pale.
Myocardium:- Discolored patch in posterior myocardium wall of left
ventricle,maybe mistaken for early infarction.
The most important, artifact is hemorrhage behind the esophagus at
the level of larynx is confused with strangulation hemorrhage appearing
in the loose tissue of back of esophagus.

34. MISINTERPRETATIONS – CONTACT FLATTENING
Collar around neck/beaded threads, ornaments – mistaken ligature
strangulation.
Parallel marks on neck when head is turned to one side – pressure
marks of fingers – Manual Strangulation
Alternate dark & light strips on the back mistaken as bruises as dead
body lying on the crumpled blanket.
Lividity on front & sides of neck in person lying on back: These areas
are due to incomplete emptying of tributaries of superficial veins of the
neck such finding shouldn’t be mistaken for bruise or throttling.

36. COLOR & INTENSITY OF LIVIDITY DEPEND UPON
Normally – pinkish initially, later blush pupil anemia
Anemia – hemorrhagic death lividity is faint
Mechanical asphyxia – intensely developed & purple
Fair skin – oblivious
Poisons :- carbon monoxide , hydrogen sulphide , cyanides, opium ,
chlorates, septic abortion
Mode of death

37. HYPOSTASIS VS CAUSE OF DEATH
Morphine Black
Hydrogen Cyanide Bright Red/Pink
Carbon Monoxide Cherry Red
Oxalic Acid Blackened Grey
Carbon Dioxide Deep Blue
Carbolic Acid Grayish White
Phosphorus Yellow
Asphyxia Blue
Hydrogen Sulphide Bluish Green
Nitrites Coffee Color

38. MEDICOLEGAL SIGNIFICANCE
1. Determine the position of body after death
2.Estimate time since death
3.Reliable sign of death
4.Color suggest cause of death
5. circumstances of death hanging, drowning, and electrocution

39. RIGOR MORTIS:
‘Rigidity Of Death(Muscles stiffening after death following general muscular
flaccidity) due to ATP depletion.
Every muscle of body is affected & Progression is proximal-distal.
First appears in involuntary muscles (within an hour) due to less mass and less
glycogen reserve
In voluntary muscles,
Small muscles groups such as eyelids, maxillo- mandibular joint because
smaller joints easily immobilized.
Begins 2-4 hours after death
Persists for about 12 hours and then begins to disappear
Takes 12-24 hours to disappear completely, passes off due to decomposition.
Timing sequence variable so it is poor indicator of time since death.

40. RIGOR MORTIS DEVELOPMENT
The sequence is variable but first facial & neck muscles before wrist
knee, shoulder, hip.
Method of detection, flexion/extension of joints. Onset of rigor may be
accelerated or retarded by number of factors, develops within 1/2/hour –
1 hour after death.
It may not appear in infants &Aged because of their feeble musculature.
Rigor spread whole muscle mass at variable time but on average 9 – 12
hours then remain stable further 9-12 hours before decomposition start
average duration of full rigor 18 – 36 hours.

42. FACTORS AFFECTING
RIGOR
⦿Temperature : colder the environment the slowest process & vice,
when near to freezing, rigor remain suspended almost indefinitely
while hot weather speed up.
⦿Physical activity before death(Mode of death) the physio-chemical
basis, the availability of glycogen and ATP. As muscular exertion
hasten the process of onset of rigor. Rigor is speedily set in electrocution
Condition of the body Emotional state
Age –children and elderly develop rigor mortis early
Physique
Surroundings

43. RIGOR IN SMOOTH MUSCLES
Heart – Rigor causes ventricular to contract which may mistaken ventricular
hypertrophy.
Rigor in the Dartos muscle of the scrotum can compress the testes & Epididymis
lead to extrusion of Semen from vesicles (wrongly thought of sexual activity &
orgasm before death).
Rigor in the erector Pilli muscle attached to the hair follicles can cause
Gooseflesh”.

44. CADAVERIC SPASM:
Rare form of instantaneous rigor develop at the time of death with no
period of muscle flaccidity.
Those deaths where intense physical/ emotional activity at time of
death, is initiated by motor nerve action.
Phenomena affect only one group of muscles such as flexors of arm,
not whole body.
It is the result of marked depletion of glycogen stores in muscles by
violent exertion. Immediately before death.

46. CADAVERIC SPASM