Death

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.