Post-Mortem Changes & Time Since Death

Question 1

Define “Death”

Answer 1

-Cessation of ALL Biological Functions

Question 2

What are the 3 Types of Death?

Answer 2

• Clinical Death
• Brain Death
• Biological Death

Question 3

What are EARLY Post-Mortem Changes?

Answer 3

• Occur in FIRST 12 - 24h - so upto a Day!
• Changes in skin / mucous membrane
• Body Cooling = aka ALGOR Mortis
• RIGOR Mortis
• LIVOR Mortis

Question 4

Describe Changes in Skin / Mucus Membrane

Answer 4

• Loss of Elasticity after death
• Skin becomes pale
• Mucous Membranes of lips, tongue + sclera become dry + dark-stained
• Occurs 2h after death

Question 5

Describe Algor Mortis aka “Body Cooling”

Answer 5

• Each body cools down at different rates
• Depends on the factors surrounding it
• Dead body loses heat via conduction, convection + radiation
• Obesity / Thick Clothing slows down heat loss, from dead bodies
• Children + Elderly cool down more rapidly

Question 6

What is Post-mortem Caloricity

Answer 6

• Where there’s Slight increase in body temp at the time of death
• Due to bodies suffering violent muscular contractions - in cases of strangulation, or septicaemia

Question 7

Define “RIGOR Mortis”

Answer 7

• It’s the STIFFENING of Muscles
• Due to chemical changes in the myoplasm
• Maximum Effect is at 8 - 12h after death at room temp
• Noticeable at eyelids - followed by facial muscles, jaw + neck
• Smaller Muscles with less glycogen reserves are affected first!

Question 8

Define “LIVOR Mortis”

Answer 8

• It’s the settling of blood into LOWERMOST BVs under gravity
• AFTER the Heart stops working
• Results in PINK Discolouration in dependent parts of the body
• IF BVs are compressed w/ clothing or surface the area will remain pale
• Occur 30 Minutes AFTER Death

Question 9

How to DIFFERENTIATE Between Lividity and Bruising

Answer 9

• Bruises occur anywhere || Lividity occurs at low-laying parts
• Lividity fades with pressure - Bruise’s DON’T
• Lividity = PURPLE
• Lividity can get incised / rinsed out w/ H20

Question 10

What are LATE Post-Mortem Changes?

Answer 10

• Occur in AFTER 24h from death
• Putrefaction
• Mummification
• Adipocere
• Anthropophagia = Where insects / animals feed on body after death

Question 11

Define “Putrefaction”

Answer 11

• It’s Post-Mortem DESTRUCTION of soft tissues in body
• Done by Bacterial (Bacterial Action) - such as Strepto / Staph / E.Coli / Clostridium
• Done by Endogenous Enzymes (Autolysis)- leading to softening + liquefaction

Question 12

Describe the Changes Occurring in Putrefaction

Answer 12

1) Green Discoloration of Right Iliac Fossa - occurs at 12 - 24h; this is where caecum lies, containing more fluid + bacteria

2) Marbling = Veins network become more visible-like a mosaic - at neck, shoulder - occurs at 36 - 48h

3) Evolution of Gases = Occurs internally, as they possess unpleasant smell - produce a lot of pressure changing the gross appearance - thereby, the “balloon effect” + Dispersion of Livor Morits

Question 13

Explain the **“Balloon Effect” and “Dispersion of Livor Morits”

Answer 13

• Balloon Effect = Where gases accumulate in hollow viscera, causing stomach + intestines to ‘balloon out’ - increasing intra-abdominal pressure resulting in abdominal distension
• Dispersion of Livor Mortis = Where gases move from blood to BVs

Question 14

Define “Mummification”

Answer 14

• It’s where the body is able to dehydrate
• Barely bacterial proliferation
• Skin becomes dark, dry + leathery
• Internal Organs dessicate + shrink
• Takes 3 - 6 Months

Question 15

Define “Adipocere”

Answer 15

• It’s where white wax-like substance is formed by hydrolysis + hydrogenation of fat tissue
• Occurs in a humid, BUT cool environment
• Visible at areas rich in fat - such as cheeks, breasts + butt
• Preserves body structures for a longer time, compared to Putrefaction