Changes after death Thanatology Practice Questions and Answers Latest Update Graded A+

Changes after death Thanatology Practice Questions and Answers Latest Update Graded A+ Immediate changes - Answers - Insensibility and absence of EEG rhythm - Cessation of respiration - cessation of circulation Early changes - Answers - facial pallor - primary flaccidity of muscles - eye changes - algor mortis - livor mortis - rigor mortis - biochemical changes in blood and body fluids Late changes - Answers - putrefaction - adipocere - mummification -entomology Importance of time since death- criminal cases - Answers the accurate determination of time since death may either inculpate or exonerate the suspect changes in the eye - Answers 1. loss of corneal reflex 2. opacity of cornea 3. flaccidity of eyeball 4. pupils 5. retinal vessels 6. chemical changes Loss of corneal reflex - Answers - found in all cases of deep insensibility - eg narcotic poisoning not reliable sign of death Opacity of cornea - Answers - cornea loses it glistening - hazy cornea -'Taches noire de la sclerotique; - if eyelids are open after death, deposition of cell debris, mucus, - triangular zone of reddish brown discolouration (taches noire) 'Taches noire de la sclerotique' - Answers - triangular zone with reddish brown discolouration with its base at the periphery of cornea Flaccidity of the eyeball - Answers - eye looks sunken and soft - reduction of intraocular tension - intraocular tension during life : 14- 25 gm < 3 gm (within 1/2 hour) - 0 by the end of 2 hours Changes in the pupils - Answers - slightly dilated soon after death - later, constricted because of rigor mortis of the constrictor muscle Retinal vessels - Answers - trucking (rail roading) - because of the fragmentation or segmentation of the blood columns seen in the retinal vessels after death - visualized by fundoscopic examination due to loss of blood pressure First- 2 hrs- pale retina 6 hrs - disc outline hazy 7-10 hrs- blurred Chemical changes - Answers a steady rise in the potassium values occurs in the vitreous humour after death Algor Mortis - Answers -Cooling of body/ Chill of Death - body temperature falls down after death - loses heat by conduction, convection, radiation - rate of cooling can be measured to determine time since death -Sigmoid shape graph is assumed - body surface loses heat rapidly but the core body temperature does not change until the gradient is established between core body temperature and the surface Gradient established in rigor mortis - Answers the rate of cooling is proportional to the difference in temperature between the body and the surface Newton's law of cooling initial plateau the curve dips down progressively before it becomes nearly flat at the bottom - curve rise before it reaches plateau due to putrefactive changes Sites to measure core body temperature - Answers rectum, abdominal cavity Instrument used to measure core body temperature - Answers chemical thermometer graduation from 0-50 degree Celsius Formula in Algor mortis- time since death - Answers (Normal body temperature- rectal temperature)/ rate of fall of temperature per hour factors affecting the rate of cooling - Answers 1. difference in temperature between the body and the surroundings 2. temperature of the body at the time of death 3. Clothings and coverings 4. Body built 5. Air currents and humidity 6. Postmortem caloricity Medicolegal importance of algor mortis - Answers estimate time since death Rigor mortis - Answers Post mortem stiffening, cadaveric rigidity state of postmortem stiffening both voluntering and involuntary muscles of the body after death succeeds the period of primary flaccidity Testing of rigor mortis - Answers Trying to :