Forensic Pathology

Question 1

List the stages of decomposition and their features

Answer 1

1. Fresh: no discoloration or insect activity, 0-5 days
2. early decomposition/bloat: discoloration, bloating, skin slough 1-21 days
3. active delay: sagging flesh, extensive insect activity, exposure of < 1/2 skeleton, mummification, 3-18 months
4. skeletonization: bones with tissue covering <1/2, dry bones, 2 months to 9 months
5. extreme decomposition: complete skeletonization with bleaching, 3 months to years

Question 2

Rigor mortis

Answer 2

This is the stiffening of muscles after death due to myosin binding to actin that begins about 1-2 hours after death and completed 12 hours after. It then disappears over the next 12 hours. It’s fixed in heat stroke and absent in botulism.

Question 3

algor mortis

Answer 3

This is cooling of the body after death of about 1.5F every hour allowing for prediction of time of death. The body feels cold between 18-24 hours.

Question 4

livor mortis

Answer 4

This is a discoloration of dependent body areas due to settling of blood that develops within 0.5 to 1 hour. Becomes fixed as erythrocytes breakdown and stain the tissue around 12 hours.

Question 5

what is the difference between cause of death, mechanism of death and manner of death?

Answer 5

The cause of death is the disease or injury that initiated events leading to death/euthanasia. The mechanism of death is the final physiologic derangement causing death (exsanguination, hypothermia, electrocution, sepsis). The manner of death is can be natural, accidental, neglect, non-accidental injury, undetermined.

Question 6

Starvation/dehydration necropsy findings

Answer 6

• low body condition score with a depletion of adipose tissue
• serous atrophy of fat = gelatinous transformation of fat
• foreign material in the stomach (eating whatever they can find won’t happen in cachexia)

Question 7

hypothermia gross necropsy findings

Answer 7

minimal, frostbite of extremities

Question 8

heat associated gross necropsy lesions

Answer 8

fixed rigor mortis, petechial hemorrhages on skin or in viscera, rapid autolysis/putrefaction

Question 9

sharp force trauma gross necropsy findings

Answer 9

• incisive wounds, depth > width
• soft tissue injury
• possible fractures

Question 10

blunt force trauma gross necropsy findings

Answer 10

abrasions, contusions, lacerations, fractures, disruption of viscera (liver lacerations)

Question 11

falls of more than __ feet usually result in injuries to the legs, jaw and ventrum (especially in cats)

Answer 11

14 feet

Question 12

asphyxiation gross necropsy findings

Answer 12

• ligature marks/bruising around the neck
• broken hyoid bones or crushed laryngeal cartilage
• emphysema or petechiae in the lungs

Question 13

drowning gross necropsy findings

Answer 13

wet, heavy lungs
froth in airways
water in stomach

Question 14

differentiate between incisional wounds and lacerations

Answer 14

in an incisional wound there is a penetrating single object that leaves clean edges and has more depth than length while in an laceration the edges are jagged and strands of epidermis may bridge the defect.