4. Postmortem changes Flashcards
Cooling off
algor mortis
Pale color
pallor mortis
Desiccation
exsiccatio postmortalis
Soaking
maceratio postmortalis
Postmortem clot
cruor postmortalis
PM blood sedimentation
hypostasis postmortalis
Discoloration
imbibition
Selfsoftening
autolysis
Grave wax
adipocere
What does PM cooling off depend on?
- hair, subcutaneous fat tissue
- temperature of surroundings
Reasons of increased PM temperature:
- overtemperature (heat stroke, septicaemia)
- spusmic muscle contraction (tetanus, strychnine or DiNitroOrtoCrezol poisoning)
Why corpse becomes pale?
- blood is settling to lower parts of an animal
- contraction of small vessels
NOT AN INFALLIBLE SIGN OF DEATH (ANEMIA)
Why dessication happens and can it happen in alive animal?
- happens bc of evaporation (skin, mucous membranes, cornea)
*can happen in alive animals in case of necrotized skin
Why soaking happens?
*skin, organs filled with fluid
- foetuses (aseptic autolysis)
- carcasses staying in water
Stiffness in skeletal muscles
– 2-4 hours the beginning
– 5-8 hours becomes general
– 24-48 hours starts to disappear
– 48-60 passes off
Specificity of rigor mortis in spleen:
Has smooth muscle interstitium (trabeculae of spleen) which will contract and spleen will be rigid. Can be confused with lesion (septicaemia -› septic splenitis -› rigid spleen)
Is stiffness of a spleen a PM change or lesion???
Stiffness in heart muscle
– Standstill in diastole – looks like systole
– Develops fast (30 minutes)
– Lasts for 1 day
Stiffness in smooth muscles
– Quick process (10-15 minutes)
– Lasts for 1 – 4 hours
Onset and duration of RM. Rapid and short
– High environmental and/or inner temperature
– Prolonged muscular activity
– Young and elder animals
– Septicaemia, wasting diseases
Onset and duration of RM. Delayed
– Asphyxial death (notably by carbon monoxide poisoning)
– Severe hemorrhage, cold surroundings
Onset and duration of RM. Fails to develop
– In case of degenerative muscle changes
Postmortem clot. Most imp inf:
- Not attached to the intima!
- After death blood clots in 15-30 minutes (Heart, large blood vessels)
- No clotting in small blood vessels - fibrinolysin
Why self softening happens?
- Autolytic ferments of the cell in the cytoplasm
- Autodigestio (esophagus and stomach mainly)
- type of autolysis
Postmortem destruction. The most imp inf
Activity of saprogenic bacteria
Suffocation supports the putrefaction– blood remains liquid
What factors increase the speed of putrefaction?
- warm environment
- obesity (body stays warmer for longer)
- hyperemic organs (fulfilled with blood)
- infection
- injuries (port of entries for bacteris)
- oedematous tissues
Other types of discolourations:
- sulph-hemoglobin (hemoglobin + hydrogen sylphid (H2S) -› greyish green color
- pseudomelanosis (iron (from hemoglobin) + hydrogen sulphyd (H2S) -› black color)
Are post mortem changes dependent on fatal disease?
No !
Are post mortem changes influenced by endogenous and environmental factors?
Yes. Very much.
Stiffness
rigor mortis
Postmortem decomposition
putrefaction
Average speed of cooling off in dogs
1 celcius degree / hour
Sequence of appearing and disappearing of rigor mortis:
Head -› Neck -› Body -› Limbs
2 most imp forms of imbibition:
- from blood (hemoglobin)
- from gall bladder (bilirubin)
What organ is very easily putrefied? And why?
Liver. Bc there are saprogenic bacteria and through vena portae they will enter the liver.
At what temperature putrefaction stops?
Under 5 degree celcius
What is the difference between autolysis and putrefaction?
Autolysis - by own enzymes of the organism
Putrefaction - by bacteria
Suffocation <-> putrefaction - ?
Suffocation supports putrefaction because blood remains liquid
“Way” of putrefaction
Intestine -> vena portae -> liver
What makes putrefaction rapid?
- obesity (retaining of the body heat)
- warm environment
- hyperaemic organs
- widespread infection
- injuries (portals of entry)
- oedematous tissues
What makes putrefaction slow?
- lean
- dehydtration
