Thanatology

ThanatologyThanatos = Death Logos = ScienceBranch of Science that deals with Study of Death.Death = Cessation of LifePermanent & Irreversible cessation of 3 Vital Systems Nervous, Circulatory RespiratoryIf any of these 3 systems fail - other two also fail Tripod of LifeCriteria for Declaration of Death - Brain DeathResp. & circulation can be maintained artificially. Irreversible brain damage occurs during theperiod of transient stoppage of resp. /circulation.Irreversible brain damage Body in Vegetative form

ThanatologyWhy Declaration of Death is important ?

Cremation

Organ Transplantation

Brain Death Diagnosed by the following tests.

Absence of corneal reflex.Dilated & Fixed Pupils - NOT reacting to light.Absence of Vestibulo-Ocular Reflex.Absence of Cranial Motor Nerve response to PainAbsence of Cough Reflex.Test withdrawal of ventilator results in Stoppage of resp.

Death may be divided into

Somatic Death

Molecular DeathSomatic / Systemic / Clinical deathDeath of the Body as a wholeSoma = BodyDuring Somatic death life is present at tissues & cellsWhen tissues & cells die, it is termed as Molecular /Cellular death.

Cellular / Molecular DeathDeath at cellular level - Occurs in partsNervous tissue 5 mts, Muscles about 3-4 hrs.

Organ which needs more blood supply during life die early due to lack of circulation.

Death is a Process - Occur in stages

First somatic death followed by Molecular death Diagnosis of Somatic death is difficult in:Soon after Death (body is warm).Suspended Animation.Coma due to Sedatives / Hypnotics.Hypothermia.ElectrocutionDrowning.

MODES OF DEATH Abnormal Physiological State at the time of death1.Coma2.Syncope3. AsphyxiaComaDeath due to irreversible damage of vital centers of brainComa may occur due to:Raised Intra-cranial pressure.Poisons (Opium, Alcohol).Metabolic disorders (uremia)

SYNCOPE (Mode of death)Failure of functions of heart.It may occur due to:Heart Disease. HemorrhagePathological condition of Blood.Cadio-toxic Poisons (Digitalis, Aconite, Oleander)

Asphyxia (MODE OF DEATH) Failure of Resp. System It may occur due to: Occlusion of Air passages.(hanging, strangulation)Breathing of irrespirable gases. Traumatic Asphyxia.Disease of Resp. System (Pneumonia)Paralysis of Resp. center (Opium poisoning)

Related to circumstances at the site of DeathSigns of DeathImmediate Signs (Signs of Somatic death)Insensibility & loss of EEG rhythm.Cessation of CIRCULATIONCessation of RESPIRTION

Signs of DeathEarly Signs (Signs of Molecular death) (with in 12-24 hrs)Cooling of Body - ALGOR MORTISChanges in the Eye.Changes in the Skin.Post mortem Lividity.Changes in the Muscles.

Signs of DeathLate Changes (Occurs about 24 hrs after death)

DecompositionModification Adipocere/ SaponificationMummification

Immediate Signs 1. Insensibility & Loss of EEG rhythm.Loss of sensation - touch, pain, temp.Loss of Voluntary power to move Loss of Reflexes.May occur due to Vagal Inhibition, Epilepsy, Drowning. Become conclusive if Loss of EEG rhythm for 5 mts.2. Cessation of CIRCULATIONHeart sounds - Not heard - for 5mts. Flat ECG for 5mts.

Not Conclusive of DeathImmediate Signs 3. Cessation of RESPIRATION Absence of breath sounds continuously for 5mts.Resp. may stop in a living person:1.Voluntary act2. Drowning3. New Born Infant

Cooling of Body / Algor Mortis Algor = ColdnessMortis = Death

After Death Heat Production - Stops Heat Loss - Continues

THANTOMETER Records temp. of Dead bodyChemical thermometer 25 cm long, marked 0-50CInserted in the Rectum 8-10 cm deep for 2-3 mts or in to the Abdomen (under Liver) by making a slit.Algor Mortis

Iso-thermic PhaseAfter death - Body temp. remains Unchanged - For 45 mtsTakes some time for Temp. Gradient to be createdb/w Inner core & Body surface SIGMOID / INVERTED S

Body Temp.Time Since DeathRate of CoolingIn 1st 2 hrs Rate of Fall in temp = Half the difference b/w body temp & the surrounding

In Next 2hrs temp falls at Half of the above rate.Thereafter temp falls slowly till the equilibrium.

In Tropical countries (India) - Avg. heat loss 0.5-0.7C / hrBody attains Env Temp in - About 16-20 hrs.

Time Since Death = Normal Body Temp Rectal temp Avg. Rate of fall in Temp / hr

Normal body temp = 37.2 CAvg. rate of fall of temp / hr = 0.6Post Mortem CaloricityIncrease in Body Temp during first few hrs after deathSun stroke, Pontine Hm (Heat regulation mechanism - Disturbed)Tetanus & Strychnine poisoningAcute Viral / Bacterial Infection: Lobar Pneumonia, Typhoid.

Rate of Cooling depends uponAge-Children, Adults of small stature - Cool rapidly (large body surface) Condition of the bodyLean bodies - Cool rapidly ; Obese bodies - Cool slowlySex Females - Cool slowly (more subcutaneous fat)Mode of Death Sudden death in Healthy person - Cools SlowlyAsphyxia, Lightning, CO poisoning Cools Slowly. Wasting disease Cools rapidly.Rate of Cooling depends uponSurroundings Well ventilated room- Body Cools rapidly Under water - Body cools rapidly Body covered with clothes / lying in bed - cools slowlyEnv. Temp Temp diff. b/w env & body is more - Body cools rapidlySkin ChangesPale, ashy white, loose translucency.Postmortem Staining / Lividity / Hypostasis / Suggilation / Vibices / Livor MortisDiscoloration or Staining of skin & organs Reason - Accumulation of bld in dependent body parts distending the toneless capillaries & veinules Starts - within an hour after deathMottled patches on dependent parts within 1-3 hrsPatches coalesce in about 3-6 hrs.

Fixation of PM StainingPosition of body changed - Lividity will not change Stagnation of blood in Distended & Toneless capillariesInability of bld to flow from toneless capillaries Staining of tissues due to diffusion of HbRigor mortis in the surrounding muscles

NOT due to - Blood CoagulationDistribution & Fixation of Lividity helps to determine: Position of dead bodyTime since death (more than 8 hrs)

Hanging - PM Staining on Dependent Lower limbsExternal Genitalia & Lower part of Forearms & Hands.

Drowning - PM Staining on Head & Upper parts of Body (Body floats with face downwards)If body is in moving water (river) Staining may not develop

Areas of Contact Flattening Lividity is absent Pressure of the body occlude toneless capillaries.

Supine position - Areas of contact flattening Back of shoulders Gluteal region Back of calves.

Skin underneath Tight clothes - Lividity absent.Tight collar around Neck - White band - mistaken as strangulation mark

Extent of Lividity depends on - Vol. of blood in circulation - duration for which blood remains liquid after death.

Excessive Bleeding - Lividity is limited in extent.

CCF - Blood vol. Increase - Lividity is marked

Color of Lividity depends on :- Color of blood Cause of death

Normal color of Lividity initially Bluish Pink afterwards Bluish Purple

Hemorrhage & Anemia- it is very faint.

Asphyxia - Lividity is prominent & purple (bld is mainly Venous & do not clot Readily)

Lobar pneumonia - Lividity is less obvious. (bld. Coagulates rapidly)CO Poisoning, Burns, Hypothermia --Bright cherry RedKCN---------------------PinkPhosphorus-----------Dark BrownHS----------------------Bluish GreenNitrites-----------------Reddish BrownPotassium Chlorate---Chocolate Brown

LIVIDITYCONGESTIONCauseCapillary & Small Vein distension with bloodPathology in the organSituation Dependent Body partswhole organ diffuselyCut Surface Oozing of blood from distended capillaries Exudation of fluid mixed with bloodSwelling & ExudationNilMay be presentMucous membrane NormalDull & lusterless (due to inflammation)Hollow organs -stretchedAlternate Stained & Unstained AreasUniform Staining Nature of change PostmortemAnte mortemLIVIDITYBRUISESituationDependent body parts Situated anywhere. Tissue level EpidermalSub epidermalsurfaceNot elevatedSurface slightly elevated marginsClearly defined DiffuseColor Uniform in colorChanges with Time CauseDistension of capillaries & veins with blood Extravasation of blood from capillaries Nature of changePostmortemAnte mortemEffect if PressurePressed spot appears blanched if PMS not fixedNo color changeCut SurfaceOozing of blood from distended capillaries which can be easily washed awayExtravasation of blood in the surrounding tissue which can not be washed away easilyM/EBlood is found within the Bld. Vessels.Blood is found outside the Bld. Vessels.MLISuggest time since death & Position of the dead bodySuggest nature of injury & weapon usedMedico-legal aspects of PM StainingReliable Sign of death.Position of body at the time of death & whether position has been changed.Time since Death.Cause of death (Color).Manner of death (distribution)Mistaken as - Bruise / Pathological condition

Muscle ChangesPrimary Relaxation Immediately after deathMuscles still react to external stimulusLower jaw - Droops, Intraocular tension - Falls, Pupils - DilateMuscles - Soft & Flabby, Joints - Flexible.Sphincters - Relax (incontinence of urine & faeces).

Rigor Mortis Shortening, Stiffening & Opacity of muscles.

Mechanism of Rigor MortisDuring Life in Relaxed State Actin & Myosin interdigitate to a lesser extent Muscles - Soft & Extensible ( due to presence of ATP)

During Movement Actin & Myosin interdigitate to greater extent ATP is converted to ADP & Energy

After Death Continuous breakdown of ATP Re-synthesis of ATP occurs till Glycogen is available. Once glycogen is exhausted - ATP is depleted Muscles lose Softness, Elasticity & Extensibility. Fusion of Actin & Myosin into a Dehydrated GelPh of Muscle changes from Alkaline to Acidic (lactic acid).

ONSET OF RIGOR MORTIS

Tested by - Gently bending the joints.Present in -Voluntary & Involuntary Muscles.Occurs earlier in - Involuntary muscles. Does not depend on - Nerve Supply of the muscle

ONSET OF RIGOR MORTIS

Amongst Involuntary muscles - appears in Heart within an hour Voluntary muscles Muscles of Eyelids------------3-4 hrsMuscles of Face----------------4-5 hrsNeck & Trunk--------------------5-7 hrsMuscles of Upper limbs------7-9 hrs Muscles of Lower limbs-----9-11 hrsSmall muscles of Fingers & Toes--11-12 hrs

Disappears in the same order in which it appears

Disappears due to - Autolysis of muscle proteins.

CUTIS ANSERINA (Cutis= Skin Anser =Goose) RM of Erector Pillae muscles of Skin Granular Puckered appearance - GOOSE SKIN Skin papillae stand out prominently with hair standing on end. Also occurs if - Body is exposed to Cold.

PERIOD OF STAY OF RIGOR MORTISIt starts in 2-3 hrs after deathTakes about 12 hrs to develop (from Head to Toe) Persist for another 12 hrs & takes about 12 hrs to pass off

Features Observed During RIGOR MORTISPartial emptying of heart.Pupils -Constricted (RM of Iris muscle) Postmortem delivery.

Rule of 12Factors Influencing RIGOR MORTIS (1) AGE Fetus < 7 month IULR M does not develop Fetus > 7month IUL develops & passes off Quickly. Children & Elderly Develops & passes off Quickly.(2) PHYSIQUEWeak Musculature ---- Develops & disappears Quickly Strong Musculature ---- Develops & disappears Slowly(3) TEMPERATUREDevelops & Passes off quickly at High temperature. Develops & disappears Slowly at low temperature.

47Factors Influencing RIGOR MORTIS

(4) Exhaustive disease / Convulsions RM appears & Passes off early.(5) Death due to Drowning Appears early due to muscular exhaustion BUT Lasts longer due to coldness of water.(6) SepticemiaRigor Mortis may be absent due to septicemia

48MedicoLegal Importance of Rigor MortisSure sign of Death.Time since Death.Position of Body at the time of Death & whether it has been altered after rigor mortis has set in. It may be confused with Cadaveric SpasmHeat StiffeningCold Stiffening Gas Stiffening

Conditions Simulating Rigor Mortis

Cold Stiffeness

Extreme Cold for Sufficient Period - Stiffness occurs (Freezing of Body Fluids & Hardening of S/C Fat

If kept at Atm. Temp. for sometime - Body becomes Flaccid After that RM appears.

Gas Stiffening: Accumulation of Putrefactive Gas in the tissues. Other putrefactive changes

Cadaveric Spasm / Instantaneous RigorStiffness of Muscles - Immediately after Death NOT preceded by Primary Relaxation

Preconditions for Cadaveric SpasmExtremely Rapid Death.Great Emotional Stress.Muscles in great physical Activity

Cadaveric spasm - a Vital Phenomenon - Starts immediately before death - Persists after death - without Primary Relaxation - Obscure Reason Other Muscles Undergo Primary RelaxationPasses off due to decomposition of Muscles MEDICOLEGAL IMPORTANCE OF CADAVERIC SPASMIndicates Sudden Death Emotional Stress and Physical activity of Muscles at the time of death.It may indicate - Manner of death. Suicide - knife/pistol - Found tightly clenched in the hand

Drowning Vegetation / other objects underneath water- found tightly clenched in hand.Homicide - Part of Cloth or Hair of the assailant found in the clenched hand

Secondary Relaxation RM disappears Muscles become Soft & Flaccid. Does NOT respond to - Mechanical / Chemical Stimuli. Muscle Reaction - Again becomes Alkaline. Secondary Relaxation - Coincides with Onset of Decomposition

PUTRERFACTION / DECOMPOSITIONLast stage of Resolution of Body from - Organic to Inorganic 1) Autolysis 2) Bacterial Action 1. Autolysis = Self DestructionEnzymes released from Cells -- Liquefy the tissues. Starts 3-4 hrs after death - Continues steadily for 2-3 days. 2. Bacterial Action Aerobes & Anaerobes. Cl. Welchii, Streptococci, E. Coli, B. proteus Cl. Welchii produce lecithinase - Hydrolyse lecithin of Cell Memb.

Warmth Moisture Air accelerates decomposition (Bacterial Growth) During Life - Organisms are within the large intestine After Death Org enter Bld. vessels & Spread throughout the Body

Features of Putrefaction1st External Sign - Greenish Discoloration of skin over Caecum & Flanks

Internal Sign - Under Surface of Liver (bowel contents - More fluid & Full of Bacteria)

Bacterial Action -- Blood is hemolysed (Hb is released) -- H2S is produced H2 S acts on Hb Sulph-metaemoglobin Features of PutrefactionColor change over the Caecum & flanks - Appear in 12-24 hrs. Discoloration Spreads to - Front of Abdomen & External Genitals. Patches appear on other Body partsWhole Body is discolored in next 24 hrs.

MarblingVeins of Root of Neck, Shoulders & Groins - Visible as Bluish or Greenish lines form a mosaic or arborescent pattern known as MARBLING.Staining of vessel wall by pigments released from decomposed bld Starts after about 24 hrs of death prominently seen in 36-48 hrs.

FOUL SMELLING GASESSimultaneously with the Color change H2S, Ammonia, Methane Gases accumulate in - S/C tissue, Hollow Viscera & eventually Solid Viscera. 12-18 hrs Abdomen - Distended.18-36 or 48 hrs - Gas formation - Abundant - Rigidity Body

Pressure Effect of GasesBloating of Features About 36 hrs Face Swollen, Discolored - Identification impossibleEyes - Bulge out. Tongue Black, Protrude Out - mistaken for StrangulationBreasts - Enormously Swollen.

In 48-72 hrs Rectum - Protrudes.Body Surface Expands Splitting of Skin Pressure marks - Form previously Well Fitting Clothes Mark on Neck - Mistaken for Strangulation.Shifting of PM Staining Pressure of Gases leads to - Displacement of PM staining Blood Clots Liquefy (due to decomposition)

Changes in Skin, Hair & Wounds Putrefactive Blisters/ Blebs (36-48 hrs) Contain mainly Gas, Little reddish fluid. Vital Reaction - Absent If Blister breaks - Patch of Raw Skin - similar to Scald. Skin gets denuded. Bruises & Abrasions - become Unrecognizable

Changes in Skin, Hair & Wounds 48-72 hrsSkin of Hand & Feet - Peel off like Glove & StockingHair - Loose & can be Pulled out easily. Ante mortem & Postmortem Wounds Oozing of blood Post mortem Bleeding

Extrusion of Fluid from Nose & MouthGases in Abdomen - Diaphragm is forced upwards Compress the Lungs & Heart Blood stained Froth oozes from Nose & Mouth.

Stomach contents - Forced out - Enter the Larynx - LungsStomach contents beyond Secondary Bronchioles indicate - Inhaled food particles are Ante-mortem in origin (Aspiration)

Emptying of HeartUpward pressure of Gases on Diaphragm - Chest CompressionChanges in GenitalsAfter 36 hrs Genitals - Enormously Swollen - Oozing of Blood tinged fluid - Mistaken as Sexual Assault In about 48-72 hrs Cervix & Uterus ProtrudePregnant female - Fetus may be Expelled (Postmortem Delivery)

APPEARANCE OF MAGGOTS

Flies are attracted to the Decomposed Body Flies Lay Eggs ------------------------------18-36 hrs.Eggs hatch into Maggots (Larva)-------24 hrs Larvae develop in to Pupae-------------- 4-5 daysPupae develop in to adult Flies ----------4-5 days

OTHER CHANGES 3-7 days Teeth - Loose & may fall out. Skull Sutures in Children - Loose & liquefied brain ooze out5-12 days Colliquative Putrefaction begins Tissues become Soft - Get converted to Semi fluid Black Mass

Abdomen Bursts - Stomach & Intestines ProtrudeSoft Tissues separate from Bones. Body is Skeletonized: 1-3 months.Bones start decomposing in 1 year in bodies buried - without coffin3-10 yrs in bodies - Laid in coffins. Decomposing bones loose wt., become fragile Bone - Totally destroyed in 10-25 yrs. Bodies lying exposed on Ground may be skeletonized in