Fme6 forensic thanatology3(scientific study of death)by dr yaseen muhammad BKMCPresentation Transcript
Death occurs in 2 stages, somatic,(systemic or clinical death) Cellular,( molecular ,death of organs) Commonly death is somatic: it is the complete & irreversible cession of vital functions of brain, heart &lungs. A person is presumed to be dead, if he cannot survive spontaneously, when the artificial means are withdrawn. Cellular or molecular death: after s.d. Tissues& cells continue to survive for varying period, when these individual cells, tissues die it is called c.d. It is accompnied by cooling, changes in eye, skin &muscles.
Life depends upon the integration of three vital systems ,respiration, circulation &innervation.called tripod of life.the persistence stoppage of any vital system eventually leads to irreversible loss of function of others, pricipetates death. Mode; stoppage or failure of the vital system; asphyxia,syncope &coma.(brain death) Cause; Disease ,physical injury ,or intoxication, which finally prove fatal Mechanism; train of changes,in the body physiology ,or biochemistry, which is incompatible e life,like asystole, v.f. hem. shock. severe acidosis, or alkalosis ,sepsis,or toxemia
Manner; way , fashion or circumstances of death Natural, due to disease Un natural; when due to causes other than disease as trauma &intoxication Accidental Homicidal suicide
S.d.or clinical death is difficult to determine just after death, when the body is 1- worm, 2- suspended animation 3-coma &hypothermia Confirmation of death is imp for 1-disposal of body 2-viability of transplant table organs like liver in 15 m , kidney in 45m, & heart in an hour. Nervous system; few min Muscular tissue; 6 hrs Cornea; 6 hrs Skin; 12 hrs
1- coma:death from failure of function of brain as in compression of brain from disease , injury ,poisons as opium , alcohol, uremia. Pm findings are; inflammation of meninges ,compression from hmrj, tumour, f.body or vascular lesion. 2-syncope:death from failure of function of heart ,due to heart disease , hmrj, blood disease . or reflux cardiac arrest ,or inhibition of the hrt due to vagal stimulation(neurogenic shock), due to sudden fright or emotion , injury to receptor areas (carotid sinus,testicles).
Vagal shock is an imp cause of death in accidental hanging , throttling , blow on epigastriam , abortion, immersion in cold water , chloroform anesthesia Asphxia: death from failure of funct of lungs : as in pneumonia, paralysis of resp centre,(opium pn) ,occlusion of air passages , gas inhalation , traumatic as RTA crushing injury Pm findings : cyanosis ,pronounced lividity , petechial hemmrorrages
Immediate : 1-insensebility &loss of eeg rhythm for a continuous period of 5-minutes Cessation of circulation: heart sounds not heard for a cont period of 5- min, a flat ecg for 5 m Cessation of repiration for 5 minutes Suspended animation: condition in which vital funct of body are so depressed that can’t be detected by routine clinical exam,as the person is not realy dead , may persist from few sec to several minutes after that person can revive, as in cerebral concussion
,drowning, electrocution, heat stroke & masmaric trance(seharzadgi, stupor, state of uncons due to magic) ( narcosis,nashawar cheez k ghalaba se behoshi) deep shock.
1-cooling of the body (a ch.thermom 25 cm long-0-50*,placed for 2-3 m,in rectem,vagina Pm caloricity; certain conditions heat is retained in 1st 2 hours,after death it is called pm caloricity. (sunstroke, pontine hrje, tetanus&strychnine p, acute infections) The rate of cooling is modified by: Age & condition of body, mode of death, environmental temp)
2-Changes in the eye (clear glistening appearance of cornea is lost, becomes dry, cloudy & opaque, corneal reflex &light reflex lost. tach naries lines appear 3-Changes in the skin (pm lividity):loses its translucency , become pale. 4-Changes in muscles(RM) Late Signs: 1-putrefaction It is resolution of body from organic to inorganic state , brought by autolysis & bacterial action. 2-adipocere formation 3-mummification Sometime the process of putref becomes arrested at some stage &fatty tissues of body may become converted into fatty acids called adipocere formation or the body tissues become dehydrated called mummification. Artificial preservation of body is called embalming.
It is discoloration or staining of skin&organs after death,due to accumolation of fluid blood in dependant parts of body. It is presented as mottled(spotted,blotch) patches 1-3 hrs, coalesce in 3-6 hrs, fully developed&fixed 6-12 hrs. Fixation of lividity is due to stagnation of blood in distended toneless capillaries&small vessels,not due to coagulation. Fixation is detected by blanching the area by thumb pressure ,if it occur,lividity is not fixed,time since death is <6 hrs,if does not blanched,it is fixed time since death is more >6 hrs.
Site &pattern of lividity depends upon the position of body after death, in hanging it is on dependent lower parts of body, in drowning as it floats face downward,it is over the head,upper parts, in moving water drowning it may not devolop. As the discoloration is due to filling of blood vessels,thus not devoloped over areas of contact flattening,if aperson is lying on his back,lividity is on his back parts except areas of contact flattening
Normally staining is at 1st bluish pink, afterward bluish purple. Certain poisoning impart a distinct color to lividity: such as < co > bright cherry red, k cyanide pink, k chlorate brown ,phosphorus dark brn, nitrites red brn, H2S bluish green , opium black &greenish brn in septic abortion. Ml imp: 1-reliable sign of death .2-position of body is shown. 3-time since death 4-its color may suggest cause of death. 5-its destribution may suggest manner of death,as in hanging &drowning.
Muscular tissues pass through certain-stagesin 1st 1-2 hrs(somatic or clinical death) Primary relaxation, as a result of loss of muscle tone lower jaw drops, eye ball loose tension, pupils dilate, mus become flaccid, sphincters relax,resulting in incontinence of urine &feaces.
It is a condition char-ed by stiffening of muscles after primary relaxation due to chemical changes,involving proteins of muscle fibres, this is the end of cellular death. Normally actin&myosin interdigitate in contraction in presence of enzyme ATP ,its production utilization is balanced in life. The overall reaction sequence is: ATP synthase + ADP + Pi → ATP Synthase + ATP,which releases energy for the cells. after death ATP is ceased, this leads to fusion of actin& myosin filaments into a dehydrate stiff gel condition called RM. RM persist until autolysis take place. due to putrefaction, secondary relaxation sets in. Rm can be broken mechanically
Rm appear in involuntary mus,then vol mus ,it is tested by gently bending .sequence is face,neck,trunk,upper limb,legs In developed rm jaw,neck,extemities are fixed, Rigidity passes off in the same order in which it occure,due to autolysis Goose skin is due to erector pilae mus affected Rm commences in 1-2 hr,after death ,take 12 hr to develop from head to foot, persist for 12 hr, take 12 hr to pass off. Time since death is <2hr if has not set in, 12-24 hr if fully developed.
This is a condition ch-ed by stiffening of mus immediately after death,e out going in primary relax, this shows somatic death in extreme rapidity, person must be in a state of emotional tension ,mus must be in physical activity. Ml imp; 1- it indicates sudden death, e great emotional tension ,physical activity,at the time of death, 2-it shows nature of death,suicide or homocide 3-in the event some clothing or hair belonging to assailant found in deceased’s hands helps in identification of murderer.
It is resolution of body from organic to inorganic state , brought by autolysis & bacterial action. Char-tic features : 1-colour changes, 2-foul smelling gases, 3-pressure effects of gases, 4-appearance of maggots Greenish discoloration over the ceacum&flanks due to sulphmet Hb formed by action of h2s of micro org, appear 12-24hr. Marbling; Veins become visible as blue or purplish lines,due to pigments from blood decomposed, this cond is called marbling, it comes after 24 hr& prominent in 36-48 hr. Gases ; side by side,colour change foul nauseating smell develop due to gases of putref( h2s,NH3,H,CO,methane.)these form below skin,in hollow viscera,cause false rigidity,exert pressure of ml imp.
Appearance of maggots; flies lay their eggs in putref body in open wounds,natural orifices by 18-36 hr, eggs hatch into maggot or larvae in 24 hr, they develop into pupae in 4-5 days, in an other 4-5 days pupae develop into adult flies,this forensic entomology imp in time since death. 3-7days teeth loose &fall, 5-12days colloquative putrefaction begins,that is liquefy &breakdown occur. cavities burst open Body is thus skeletanised in 1-3 months Bones begin to decompose in 3-10yrs
1-Sometime the process of putref becomes arrested at some stage &fatty tissues of body may become converted into fatty acids called adipocere formation or 2- the body tissues become dehydrated/dessicated called mumification. 3-Artificial preservation of body is called emballming.(embalming fluid,contain formaldehyde, arsenic , lead sulfide , k corbonate into femoral artery . cold storage also used for preservation. 4-warmth&clothing, 5-moisture, air, 6-maner of burial, 7- also age& condition of body ,sex, 8- mode of death Time req for adipocere varies from 3-6 weeks
1-;identity, 2-cause of death , 3-time since death, 4- it indicates place(water or moist grd) Mummification; time for it varies from3m -1 yr. Same ml imp as adpr, except it indicates hot dry area.
1-Cooling of body;due to progressive heat loss body attains envirnm temp in 12-15hrs 2-Pm lividity;the incidence,extent,degree of fixation is imp .it commences in an hr. mottled patches within 1-3hr ,patches coalesce in 3-6hr, fully developed&fixed in 6-12hr. 3-Rm ;commences 1-2hr, takes 12hr to develop,from head to foot ,persist for 12hr,take 12hr to pass off.
Decomposition changes ;12-24hr-greenish discoloration of abdomen, spreads in 24hr ,Marbling comes after 24hr ,prominent 36-48hr,same time putref odour is present. 12-18hr gases collect in intestines&distend the abdoonen. 48-78hr rectum,uterus protrude, 18-36hr flies lay their eggs, it hatch into larva in24hr, 4-5 days maggot develop into pupae, in an other 4-5days pupae into flies .3-7days teeth &sutures of skull become loose .5-12days soft tissues lequefy&breakdown. 1-3m body is skeletanised. adipocere 5-15days,;mumification 1-3m.
Growth of hair on face ,lice in hair,state of dress,&personal effects. Presumption of death; a legal presump is that,he is still alive,unless it is proved that the person has not been heard for 7 yrs by those who are in normal contact e him if he had been alive,in which case the law presumes that he is dead.
Every one is sane(wise,sensible,rational) & responsible for his action