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Flashcards in Postmortem Changes Deck (23):


the irreversible failure of the CV system


What happens after death?

-failure of O2 delivery to the tissues resulting in cellular death
-energy production ceases and the body cools
- circulating blood becomes stagnant and settles under the effects of gravity
-the usual body defences fail and it can no longer inhibit the proliferation of bacteria- putrefaction ensues


How long after death is body temperature relevant?

up to 12 hours


What factors influence the rate of body cooling?

-nature of clothing
-usual temp
-natural insulation of body
-convection currents
-environmental temp
-length of plateau of cooling curve


What is the rule of thumb when it comes to body cooling?

1 degree per hour


How accurate can body temp be in time of death?

no better than +/- 2.5 hours


Why can the rate at which the stomach empties not be used as an indication of TOD?

Too many influencing factors:
-nature/amount of food
-solids vs liquids
-certain medication


What is rigor mortis?

stiffening and shortening of muscle fibres leading to rigidity of the musculature and fixation of the joints


What causes rigor mortis?

the reduction of ATP within the muscles after death


Describe the timeline of rigor mortis

-becomes apparent 5-7 hours after death
-usually fully established 8-12 hours after death
-dissipates in line with ensuing decomposition and frequently absent by 36 hours after death


What will affect the development of rigor?

ambient temperature


What causes putrefaction?

the action of bacterial micro-organisms; process begins at death but takes a period of time to become detectable


What variables should be considered with putrefaction?

-ambient temp
-cleanliness of the environment


Describe the timeline of putrefaction

-2-3 day: greenish discolouration of the abdominal skin
-1 week: blister formation and tissue swelling, including gas formation in body cavities, Vascular marbling can be seen



-a process of fry decomposition with desiccation of the body and a relative lack of bacterial involvement.
-body essentially dries out the facial features and hands/feet may become rigid


What induces adipocere formation?

the alteration of fatty tissue within the body into a greasy/waxy or brittle material which frequently remains attached to the bony skeleton and may retain the body structure to some extent. tends to occur in wet environments


What variables exist in skeletonisation?

exposure to meat eating animals and to dipterous larvae


Post mortem hypostasis/PM lividity/PM staining

represents the pooling of stagnant blood in dependent regions of the body under the influence of gravity


Describe the timeline of PM hypostasis.

begins as soon as the circulation of blood ceases but takes time to become visible usually about 1-2 hours and fully established by 6-12 hours


What is pressure pallor?

where the body surface has pressure applied there will be compression of the blood vessel preventing ingress of blood


What can the colour of hypostasis tell us?

-pink/purple= normal
-cherry red= carbon monoxide poisoning


PM artefacts

alteration or damage to body occurring after death which may mimic genuine processes occurring in life


What are examples of PM artefact?

-animal predation
-traumatic injury