Medico-Legal Autopsy and Postmortem Changes (Thanatology) MCQs

Forensic Medicine · 49 free questions with answers & explanations.

1. A body is found 18 hours after death in a temperate environment. Rigor mortis is well established throughout. When rigor begins to pass off in a sequential manner, which body region loses rigor LAST, and why?
2. Putrefaction produces a range of gases and chemicals. Which combination is SPECIFICALLY responsible for the greenish-black skin discolouration seen in putrefaction, beginning in the right iliac fossa?
3. Vitreous humour is the preferred post-mortem fluid for alcohol and glucose estimation because it is protected from putrefaction. An additional advantage is its utility in establishing ante-mortem hyperglycaemia. Post-mortem vitreous glucose is considered reliable up to approximately:
4. Adipocere formation is a post-mortem change that preserves the body's shape. Which condition MOST favours adipocere formation?
5. Post-mortem lividity (hypostasis) is used to estimate the time and position at death. Which statement about post-mortem lividity is CORRECT?
6. At scene examination 18 hours after death in a tropical climate (ambient temperature 35°C), a body exhibits fixed lividity, full rigor mortis, and an unusual cherry-red discoloration of lividity and underlying tissues. There is no smell of bitter almonds. The MOST likely cause of death consistent with the cherry-red discoloration in this setting is:
7. A forensic pathologist is calculating the approximate postmortem interval using Newton's law of cooling. The body temperature is 30°C, the ambient temperature is 20°C, and the normal living body temperature is assumed to be 37°C. Using the Henssge nomogram assumption, approximately how many hours have elapsed since death? (Approximate only — assume standard body weight and no modifying factors)
8. A body is exhumed 3 years after burial in a waterlogged soil. The soft tissues are converted to a yellowish-white, waxy, soap-like substance with a rancid odour. Microscopically, the tissue is replaced by a material that does NOT stain with fat stains. What has occurred?
9. In early putrefaction, the characteristic greenish discoloration first appears over the:
10. Casper's dictum compares the rate of decomposition of a body in different environments. What is the correct ratio it describes?
11. A body is found in a temperate environment. Postmortem calorimetry reveals a rectal temperature of 30°C. Ambient temperature is 20°C and normal body temperature is assumed to be 37°C. Using the Henssge nomogram with a body weight of 70 kg on a dry surface, what is the MOST important correction factor applied when the body is found clothed?
12. Adipocere formation was detected in a body exhumed 8 months after burial in a waterlogged coffin. Which biochemical pathway is PRIMARILY responsible for the saponification of subcutaneous fat?
13. At autopsy, a body shows dark red lividity that does NOT blanch on pressure and cannot be shifted by repositioning the body. These findings indicate postmortem interval of approximately:
14. A forensic pathologist notes that on sectioning rigor mortis-affected muscle at autopsy, the muscle has a pale, cooked appearance and fails to exhibit the normal rigor on sustained contraction. This change is MOST consistent with:
15. Vitreous humour is preferred over blood for postmortem biochemistry because it is relatively protected from putrefaction. Which ion shows the MOST reliable postmortem rise in vitreous humour and is used as a marker of the time since death in the early postmortem period?
16. A body is found with well-developed rigor mortis in all muscle groups. Temperature of the body is 27°C in an ambient temperature of 22°C. Using the Henssge nomogram and assuming a standard body weight of 70 kg, the estimated time since death (TSD) would be approximately:
17. At autopsy, livor mortis is found to be fully fixed (not shifting on turning the body) and bright pink. The most likely interpretation is:
18. In tropical forensic practice, the phenomenon of 'saponification' (adipocere formation) differs from putrefaction in that:
19. Pugilistic attitude seen in fire deaths is due to:
20. The 'gastric emptying' method of estimating time of death relies on comparing the state of digestion with the deceased's last known meal. This method is MOST unreliable because:
21. Flies of the family Calliphoridae (blowflies) are of greatest forensic entomological importance because:
22. At autopsy of a newborn, the hydrostatic lung test (docimasia pulmonaris hydrostatica) is found to be positive (lungs float). This finding indicates that the child:
23. Adipocere formation requires the conversion of body fat to a waxy substance primarily composed of which chemical compound?
24. A body recovered after 10 days in a warm, humid Indian summer shows greenish discolouration starting at the right iliac fossa. The primary organism responsible for this initial surface change is:
25. In determining the postmortem interval (PMI), the formula used with body temperature is the Henssge nomogram. Which statement about its application in Indian forensic practice is MOST accurate?
26. Mummification (dry gangrene of the body) occurs in all of the following conditions EXCEPT:
27. A body exhumed after 3 months shows no putrefaction, with soft tissues converted to a yellowish-white waxy material. The minimum temperature required to initiate this postmortem change is approximately:
28. Casper's dictum in forensic thanatology states that a body in AIR decomposes as fast as a body in WATER in how many weeks, and as fast as a body buried in EARTH in how many weeks?
29. A body is found in a cold room (5°C) with deep rigor mortis of all muscle groups. Rigor was noted to have started approximately 12 hours ago. Considering the cold environment's effect on rigor mortis, which statement is MOST accurate?
30. Postmortem lividity (livor mortis) that does NOT blanch on firm finger pressure after 8–12 hours indicates which postmortem change has occurred?
31. An intact blister is found over the dorsum of the hand of a body discovered indoors. The blister fluid is haemorrhagic and the skin shows no thermal burn marks. This finding is MOST consistent with:
32. In a body recovered from tropical outdoor conditions, putrefaction has progressed to marbling — the green-black arborescent discolouration of skin following superficial vein patterns. The BEST time estimate for this degree of decomposition in a hot-humid Indian climate (35°C) is approximately:
33. Adipocere formation is more likely to develop in a body submerged in water or buried in damp soil. The chemical process converting body fat into adipocere involves:
34. Mummification of a body occurs when:
35. A body found in a river shows skin peeling in large sheets, marbling of the skin, and a faint greenish discolouration over the abdomen. The face is bloated with gas. Which stage of decomposition is this MOST consistent with, and what is the estimated minimum postmortem interval in a temperate environment at 20°C?
36. In a case of suspected poisoning, the pathologist notices a cherry-red discolouration of the postmortem hypostasis. The MOST likely toxin responsible is:
37. Mummification as a postmortem change requires which specific set of environmental conditions?
38. A body is found with lividity that is cherry-red on the dependent back but also on the non-dependent face and anterior trunk. The MOST appropriate interpretation is:
39. Mummification as a form of delayed postmortem change occurs under which specific environmental conditions, and the minimum time for complete mummification of an adult body in favourable conditions is approximately:
40. At autopsy 18 hours after death in a tropical climate (30°C), a body shows cadaveric rigidity that is well established. A small amount of purplish discoloration is noted on the face with a few gas-filled blebs on the skin. Lividity is fixed and well distributed on the back. What is the sequence and timing of postmortem changes that accounts for these findings?
41. Adipocere formation in a body submerged in water for several months is the result of which biochemical process, and what is its forensic value?
42. Rigor mortis first appears in which muscle group after death?
43. A body found after 3 days in a warm climate shows green discolouration of the right iliac fossa. This is the earliest sign of:
44. Postmortem lividity (hypostasis) becomes fixed and cannot be shifted to a new dependent area after approximately:
45. At autopsy, which of the following is the most reliable early indicator of time since death when performed within the first 24 hours?
46. Adipocere formation is promoted by which environmental conditions?
47. A body is discovered outdoors in summer. It is heavily infested with large white maggots of the third larval instar (L3). The maximum size of the maggots is 15 mm. The ambient average temperature over the past days was 25°C. Forensic entomologists use the concept of accumulated degree days (ADD) or degree hours to estimate the minimum postmortem interval. Which fly species is MOST commonly the first coloniser in a decomposing human body in tropical India, and whose development data are used for such calculations?
48. Rigor mortis in skeletal muscle begins approximately 1–3 hours after death at room temperature (23°C) and is fully established (in-sensu complete) by approximately 6–12 hours. The biochemical mechanism driving rigor is:
49. At autopsy, the eyes of a body show "tache noire sclérotique" — a brownish-black, triangular, leathery discoloration of the exposed sclera in the palpebral aperture. This change indicates: