DeathHarshita thotaRoll no:108 (2013-14)
Definition
Death is defined as the irreversible cessation of life, insensibility , inability to move and permanent and complete stoppage of vital organs of the body
Types/stages of death
Death
Somatic, systemic or clinical
Molecular or cellular
Somatic death
It refers to death of tissue / system / body and is clinical death .Brain ,
heart and lungs stop
functioning
Oxygen supply is stopped
Aerobic process
es cease
Tissue death
However , the anaerobic enzymatic processes are still continuing ,hence :
1. Muscles still respond to various stimuli i.e. mechanical , electrical and thermal .
2. pupils still respond to meiotics and mydriatics
Somatic death is associated with immediate signs of death like :
Permanent and complete cessation of brain and flat EEGPermanent and
complete cessation of heart and flat ECG.Permanent and complete cessation of lungs .
Molecular death It occurs after somatic death . It refers to death of individual cells
. It happens when the anaerobic
processes also stop , due to non availability of ATP . at this stage :
1. Muscles do not respond to stimuli .
2. Pupils do not respond to stimuli or drugs .
Molecular death is associated with early and late signs of deathEarly
signs
Changes in eyes
Changes in skin
Changes in muscles
Cooling of the body
Postmortem lividity
Late signs
decomposition
Adipocere formation mummifica
tion
Molecular death occurs at varying intervals after somatic death:
organ durationNervous tissue After about 5 mins.
Liver After about 15 mins.
heart After about 45 mins.
kidney After about 1 hour.
muscles After about 3 hours
cornea After about 6 hours
After about 6 hoursblood
Modes of death1. As per Gordon
Modes of
death
Anoxic anoxia Anaemi
c anoxia
Stagnant
anoxia
Histotoxic
anoxia
Anoxic anoxia1. Reduced oxygen availability.2. So reduced oxygenation of bloodExamples: mechanical obstruction, high
altitude and irrespirable gases .
Reduced oxygen carrying capacity of blood Examples : hemorrhages , respiratory poisons
including carbon mono oxide.
Anaemic anoxia
Defective utilization of oxygen by tissues .Examples: cyanide poisoning and lung fibrosis
etc.
Due to defective circulation.Examples: heart failure, shock , embolism etc.
Histotoxic anoxia
stagnant anoxia
2.As per Bitchat ( presently accepted classification)
Modes of
death
Coma syncope
asphaxia
comaDefinition:Coma can be defined as a mode of
death, where death results from failure of function of brain .
Clinically, coma can be also used to designate unconsciousness where the unconsciousness is complete, without any response to any stimulus , it is termed as deep coma .
Causes of coma
causes
Raised intracra
nial tension
Injury to brai
npoiso
ns
Pathological
disorders
Metabolic
disorders
syncopeDefinition:
Syncope is defined as the mode of death where death results from the failure of heart.
Causes of syncope
causes
anemia astheniaNeuroge
nic shock
exhaustion
asphyxia Asphyxia is the mode of death where the
death is caused due to the failure of lungs Causes:1. Mechanical obstruction to airways2. Hypoxia3. Pulmonary embolism4. Collapse of lungs5. Improper chest movements6.Respiratory poisons 7.Pathological conditions
Changes after deathChanges in eyes1. Abolition of pupillary and corneal
reflexes.
2.The eye losses its lustre .cornea becomes dry , hard ,hazy and opaque .
Temporary change : After 15- 30 mins of death.Permanent change : after 10 – 12 hours of death.
These changes can be present even before death ( rarely) e.g in narcotic poison , cholera etc.
Cant be present in conditions like cyanide poisoning and carbon mono oxide poisoning.
Pupil dilates after death. React to mydriatrics and meiotics : for 1-
2 hours after death. After 2-3 hours , any pressure on pupils
change its shape to oval , triangular or polygonal .
Intraocular tension falls after death and eyeball sinks into orbit .
If eye remains open after death : dust deposition – brown pigmentation known as traches noires.
Retinal blood vessels :After 1-2 hours of death- dotted.After 2 -3 hours of death – it becomes
segmented.After 3 hours - segmented . rise in electrolytes like
potassium and ascorbic acid levels
in vitreous humour.
Changes in skinColor changes : After death the skin becomes greyish white . Decomposition causes greenish discoloration .
Loss of translucency Loss of elasticity Lips becomes dry , hard and brown in color
due to drying .
After death there is cooling of the dead body _ Algor mortis .
Time since death =normal rectal temperature –
observed rectal temperature
rate of fall of temp. per hour
Changes in the temperature
Postmortem lividityAs the dead body behaves like an inert substance , therefore there is gravitational flow of blood to dependent parts of the body , causing stagnation of blood in the toneless , dilated capillaries ,resulting in bluish purple staining of these parts .
Changes in muscles after death 1. primary relaxation of muscles 2. contraction /stiffening of muscles –
rigor mortis
Late signsdecomposition1.Putrefication: (in air ,water and earth )This is due to:1. Autolysis 2. 2. enzymes released by bacteria .3. gas formed distends whole body.4. organs becomes soft and greezy .
2. Saponification :Adipocere formation : this is due to hydrolysis and
hydrogenation of body fats , so as to converts these fats into fatty acids.
3. Mummification :
Mummification is defined as dessication or drying up of dead body . It is also a modification of decomposition .
Medico legal aspects 1. time since death 2. presumption of death can be done is the
person is not heard of for 7 years or more. 3. it is also important in : a) inheritance of property b) Obtaining insurance money c) Second marriage without liability to bigamy. 4. place where the dead body was lying by
adipocere formation.