Thanatology is the scientific study of death, including the causes and processes of death. Death is defined as the irreversible cessation of life through the permanent stoppage of circulatory, respiratory, and nervous systems. There are two main types of death - somatic/clinical death which is the loss of brain and body functions, and molecular/cellular death which is the death of individual cells after circulation and respiration cease. Brain death is considered legal death and can be of three types - cortical, brain stem, or whole brain. Determining death involves examining for the absence of brain stem reflexes and apnea during an apnea test. The causes, manner, timing and certification of death are important for legal and medical reasons including

1. DEATH
OR
THANTOLOGY

2. Definition :
•Thanatology (Greek - Thanatos : Death)
Logus : Science
is the scientific study of death, types of
death including its cause and phenomena,
bodily changes or events that accompany
death in cadaver (postmortem changes) in
all its aspects and their MLI.

3. Definition of Death:
• Black’s Laws Dictionary defines death as “the cessation of
Life”
• Others defines as – “ irreversible cessation of life”.
• Physicians declares death with complete cessation of all the
vital functions of nervous, circulatory & Respiratory systems.
• “Death is permanent & irreversible cessation of the functions
of the 3 interlinked vital systems of the body namely, the
nervous, circulatory & respiratory systems”.
“TRIPOD OF LIFE”

4. • Harvard Committee on Brain Stem death:
1. Unresponsitivity
2. No movements or breathing
3. No reflexes
In addition to these – Flat ECG & EEG
Section 2(b) of Registration of Birth & Death Act 1969 defines death as “
permanent disappearance of all evidence of life at any time after live
birth has taken place”

5. Medico-legal implication of Death :
1. Declaration of Death
2. Certificate of Death
3. Disposal of the body/cadaver
4. Organ Transplantation
5. Death & IPC - Section 46 IPC
6. Question of Survivorship
7. Legal presumption – if person is unheard for 7 years , court on
application by close relatives , may presume Death have been taken place
under Section 108 , Indian Evidence Act 1872

6. Types of Death:
i. Somatic or systemic or clinical:
 Loss of sensibility & inability to move(movement of limbs & chest while breathing).
• Complete and irreversible cessation of functions of circulatory, respiratory and
central nervous system
• Physical stoppage of function of heart,lungs,brain.
• But , Individual cells may not die, may responds to chemical , thermal or electric
stimuli.
ii. Molecular or cellular:
 Molecular death means death of individual cells of different tissues or organs.
 In the absence of circulation & respiration , different cells dies at different time after
somatic death – depending on metabolic activity & availability of oxygen.
 Brain cells dies earlier than any other organs.

8. The gap between somatic death and
molecular death is important for two
reasons:
1.Disposal of body
2.Tranplantation purpose
(cadaveric organ transplantation )

9. BRAIN DEATH :
3 TYPES:
1. Cortical Brain Death
2. Brain Stem Death
3. Whole brain Death
1. Cortical Brain Death or Cerebral death-
• In this Brain stem is INTACT, with continues heart sounds & respiration –
maintaining Cardiac activity & Respiration - patient is in Vegetative State.
i.e Persistent Vegetative State (PVS) – Continues Cardiac & Respiratory activity +
total LOSS of sense of perceiving & feeling things.
Also Called as “Living Cadavers” – these vegetative peoples are not considered as
DEAD.
• Clinically patient is in condition of irreversible coma and shows signs of severe brain
dysfunction

12. 2.BRAIN STEM DEATH
 Practically - Brain stem Death is considered as death of a person because the vital
centres that controls Respiration , Cardiac & other centres that controls the
awakens are lost irreversibly & permanently.
 Transplantation of Human Organs & Tissues Act defines Brainstem death as –
“ the stage at which all functions of the brainstem are permanently & irreversibly
ceased”.
3. Whole Brain Death :
Also called as mixed brain death.
Combination of Cortical & Brain stem death.

13. Brain stem death
•“the stage at which all functions of
brain stem have permanently and
irreversibly ceased and is so certified “
•Practically brainstem death is
considered as death of a person.

14. Diagnosis of Brain Stem Death :
• Early determination– i) promotes harvesting of organs for transplantation purpose.
ii) discontinuation of life supporting equipment.
iii) determination of time since death.
Consists of Establishing following things :
1. Patient is in deep comatose state , unable to breath spontaneously , in
unconscious state – need to be maintained on ventilator.
2. Absence of Brain Stem reflexes.
3. Negative Apnoeic Test.
4. Exclusion of other causes of coma – Ex : Apparent Death , Drugs , Prolonged
Hypoxia , Trauma, Hypothermia , Intoxication , Metabolic & Endocrine
disturbances.

15. Brainstem reflexes
1.Absence of pupillary response. (Light reflex)
2.Absence of corneal reflex.
3.Absence of vestibulo-occular reflex- Irrigation of Ice cold water into
External ear. (tympanic membrane)
4.Absence of grimace reflex – Pinching over the Face.
5.Absence of cough/gag reflex – Tickle Soft palate/throat
6.Absence of spontaneous respiration.
APNOEIC TEST:
After giving 100% oxygen for 5 min, patient is disconnected
from the ventilator for 10 min – if No Respiratory movement occurs.
If no spontaneous breathing of any sort occurs within those 10
min – confirms Death.

16. Harvard criteria of Brain death :
1.Unreceptivity & unresponsivity –total unawareness to
external stimuli &unresponsive to painful stimuli
2.No movements
3.Apnea-absence of spontaneous respiration at least one
hour
4.Absence of elicitable reflexes
5.Isoelectric EEG

17. Brain Death Certification
1. Two medical practitioners must perform the
brainstem death tests.
2. The patient’s attending physician should
participate in the determination of death
wherever possible.
3. The doctors involved should be experts in the
technique of brain death assessment.
4. Each doctor should perform the tests twice.

18. Organ transplantation
• The success of homograft mainly depends on
1.Type of tissue involved .
2.Rapididity of its removal after circulation has
stopped.
Cornea - within 6 hrs
Skin - within 24 hrs
Bones - within 48 hrs
Kidneys , heart , intestine , liver -
soon after circulation stops

19. Causes of Death:
1. Immediate Causes
2. Basic/Antecedent/Underlying causes
3. Contributory Causes
1. Immediate Causes:
immediate or terminal events leading to death.
Ex: Myocardial Infraction
2. Contributory Causes:
Pathological process involving in or complicating or contributing to the death.
Ex: DM , HTN

20. 3. Basic Cause:
 Pathological process or injury responsible for death.
 Injury or any disease has initiated the chain of morbid events leading
directly to death.
Ex : Circumstance of accident or violence
Hepatic or Renal pathology.

21. APPARENT DEATH
(Suspended Animation)

22. Suspended Animation
"A state of body in which the vital functions are at a low
pitch that the body functions cannot be determined by
ordinary methods of clinical examination".
In this , the circulation, respiration do not stop but is
being maintained in there minimum.
By Clinical examination : Pulse - not felt/palpable
BP – not recordable
Heart sounds – Not audible

23. CAUSES OF SUSPENDED ANIMATION

26. A = Asphyxia
C = Coma
S = Syncope
• Asphyxia i.e failure of function of respiratory system.
• Coma i.e failure of function of brain.
• Syncope i.e failure of function of heart.

28. Asphyxia
• State in living organism there is a acute lack of oxygen
available for cell metabolism
• Associate with inability of body to eliminate excessive
carbon dioxide
• Condition resulting from interference with Respiration
or sudden stoppage of functioning of lungs causing
Unconsciousness & Death.

29. Mechanism of Asphyxia:
Sudden stoppage of or failure of functioning of lungs
Impaired Blood Oxygenation
TISSUSE ANOXIA
Nervous tissue(Brain) is affected first followed by other tissues by disturbing their functions.
Failure of Vital Centre & DEATH.
In all Asphyxia , after stoppage of respiration ,Heart may continue to beat for several
minutes.
RULE OF THUMB : Cardiac Arrest – breathing stops within 20 seconds
Respiratory Arrest – Heart stops within 20 minutes.

30. Clinical Features :
3 stages – may last for 3 to 5 minutes
1. Stage of Dyspnoea
2. Stage of Convulsions
3. Stage of Exhaustion & Respiratory Failure
1. Stage of Dyspnoea : Due to excessive accumulation of carbon dioxide , stimulates Respiratory
centre - resulting in increased rate & respiratory movements.
2. Stage of Convulsions : due to lack of Oxygen – laboured respiration , clouding of consciousness,
convulsion, Sphincter relaxation, Congestion & Cyanosis of face & Hands.
stage last for 1-2 minutes.
3. Stage of Exhaustion & Respiratory Failure : Last for 2 to 3 minutes.
Respiratory & others Nervous centres are completely paralyzed.
Muscles are flaccid , Reflexes are lost , Breathing – Gasping , Pulse - Feeble

31. Coma
• Unarousable & Unconscious state of person characterized by complete insensibility.
• When patient is partially conscious & response to deep &painful stimuli is called
stupor
• Result of sudden stoppage of functioning of Brain.

32. Coma
• Unarousable & Unconscious state of person characterized by complete insensibility.
• When patient is partially conscious & response to deep &painful stimuli is called
stupor
• Result of sudden stoppage of functioning of Brain.

33. Syncope
• Syncope result from stoppage of functioning of heart with
consequencent cessation of circulation
• In syncope there occurs loss of consciousness with posture
collapse due to an acute decrease in cerebral blood flow

34. Mechanism of Syncope (Fainting) :
Acute reflex
Circulatory
changes
Ischemia of
Vital centres
of Brain &
Death.

35. CAUSES :
1. Anaemia due to sudden & Excessive haemorrhage.
2. Asthenia due to deficient power of Heart Muscle.
3. Myocardial Infraction
4. Poisoning with Cardiac poisons
5. Sudden fright , emotion
6. Injury (blow to epigastrium)
CLINICAL FEATURES :
1. Pallor of face & lips . 6. Dimness of vision
2. Dilated Pupils 7. Skin-cold with perspiration
3. Gasping Respiration 8. Nausea , Vomiting
4. Pulse - Weak/Feeble/Slow 9. Fall in BP
5. Delirium, Convulsion 10. Death

38. Manner of death
• The way / design / fashion in which cause of
death comes into being / reality.
• Types
1. Natural
2. Unnatural – 3 types
i. Homicidal
ii. Suicide
iii. Accident

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