28. The Body After Death Flashcards
What factors help estimate the time of death?
Changes in the body
Environmental evidence
Anamnesic evidence
What is the best method of estimating the time of death?
Core body temperature
What steps must you undergo before pronouncing death?
Pupillary light reflex Absence of breath Absence of heart sounds Absence of pulse Each checked for 1 min
What immediate changes happen after death?
No BP or oxygen
Loss of neuronal activity
Breathing stops
Small muscle twitches
What are the early changes after death?
Rigor mortis
Livor mortis
Algor mortis
What is the chemical process that causes rigor mortis?
Anaerobic metabolism in muscle leads to high lactic acid
irreversible actin and myosin binding lead to muscle rigidity
Which muscles does rigor mortis usually start in?
jaw, face, neck
What does the rate of onset of rigor mortis depend on?
Temperature (faster if warm) Physical activity before death Age Sex Build (faster in more muscle) Condition (faster in sepsis)
Give examples of how rigor mortis also affects organs
Causes myocardial contraction
Iris contraction can cause unequal pupils
Goose flesh
What is the time of death estimation if the body is warm and flaccid?
<3 hours
What is the time of death estimation if the body is warm and stiff?
2-8 hours
What is the time of death estimation if the body is cold and stiff?
8-36 hours
What is the time of death estimation if the body is cold and flaccid?
> 36 hours
What is cadaveric spasm?
Rare form of instantaneous rigor
Happens when person dies in the middle of intense physical or emotional activity
What are 2 more names for livor mortis?
Lividity
Hypostasis
What is livor mortis?
Gravity causes pooling of blood in veins and capillaries
Pink/purple/blue discoloration
No pooling in areas that were in contact with underlying surfaces
What is livor mortis useful for?
Can indicate if the body was moved after death
What can petechiae indicate?
Asphyxiation
What does cherry pink lividity indicate?
CO poisoning
What does pink lividity indicate?
Hypothermia
What does brick red lividity indicate?
Cyanide poisoning
What does bronze lividity indicate?
Clostridia perfringens sepsis
What is algor mortis?
The cooling of the body after death
Core temp falls by about 1C every hour after 3.5 hours
What is Newton’s law of cooling?
Warm body in a cool environment will lose heat from its surface until temperature equilibrilates
