Post - mortem changes and identifying the time of death

Question 1

What is death? (the definition used in this lecture)

Answer 1

The irreversible failure of the cardiovascular system.

Question 2

What are the five stages of death?

Answer 2

1- pallor mortis = lightening of skin 
2- Livor mortis = settling of blood
3- algor mortis = temp 
4 - rigor mortis = stiffening and shortening of muscle fibres
5-decomposition and purification

Question 3

Is measurement of body temp good for determining the time of death?

Answer 3

it is not that accurate , + - 2.5 hours.

due to other factors - e.g. clothes, environmental temp

Question 4

can stomach contents be used for determining death?

Answer 4

nope. there are too many factors that affect it - e.g. nature/ amount of food, solid, liquid, medication etc.

Question 5

what is rigor mortis ?

Answer 5

stiffening and shortening of muscle fibres - leads to rigid muscles and fixed joints. Due to less ATP

Question 6

When is rigor mortis apparent, and when is it fully established?

Answer 6

Apparent - 5 -7 hours

Fully established - 8 - 12 hours

Question 7

why does the body return to a fluid state around 36 hours after rigor mortis?

Answer 7

decomposition

Question 8

What can be mistaken for rigor mortis?

Answer 8

cadaveric spasm

Question 9

what does decomposition rate depend on?

Answer 9

temperature, humidity, cleanliness

Question 10

what is adipocere formation?

Answer 10

corpse wax, stays on skeleton.

Question 11

what radioisotopes can be used to age bone?

Answer 11

Strontium and polonium

Question 12

what is Post mortem hypostatis / post mortem lividity?

Answer 12

pooling of stagnant blood.
visible at 1 - 2 hours, established at 6 - 12.
Does not occur at bit that were touching ground - so can be helpful to determine the position of death.