Post Mortem Interval (PMI) Flashcards
post mortem interval
time since death
what happens when the time frame of finding a body increases?
the specific time of death decreases
what happens in the first 24 hours of death?
mortis changes occur; because it is within the first 24 hours, the time of death can be more specific
algor mortis
cooling of body temperature
livor mortis
settling of blood, causes discoloration in the skin
rigor mortis
amount of muscle stiffness
vitreous humors
changes in the eye fluid
who is called after 24 hours of death?
- forensic entomologist
- forensic botanist
- forensic anthropologist
- uses decomposition, skeletonization, and forensic taphonomy
two factors of decomposition
autolysis and putrefaction
autolysis
- degeneration of body tissue by digestive fluids in the intestinal tract
- digest the body like food, causing destruction of internal organs
putrefaction
- breakdown of biological elements due to the proliferation of microorganisms normally present in the body
- occurs due to unhindered production of bacteria which eat away at tissues
- causes bloating
what are the stages of decomposition?
- fresh death
- bloating
- active decay
- skeletonization
what factors affect decomposition?
temperature, humidity, and accessibility
what happens to remains in warm areas?
display more insect activity and decay faster
what happens to remains in dry areas?
they decompose slower (desicate)
what happens to remains in open areas/with open wounds?
attract animals and decompose faster
who eats the body first?
- maggots
- beetles
- carnivors
- rodents
what do adult and larvae beetles eat?
larvae eat decaying wet tissues, and adults eat drier tissues
how do insects affect PMI?
- insects appear in predictable patterns
- their lifecycles are used to predict PMI
which two insects ratios can you use to predict PMI?
beetles and flies
how many months after death do cheese flies appear?
3-6 months
what can insects help determine?
- the time since death
- season since death
- geological location
- personal habits of the decedent
what happens to remains within the first week?
- bloating and collapse
- maggots on face, predatory beetles
- skin slippage
- bones become exposed
what happens to remains within the first month?
- dermestid beetles
- bones exposed
- mummification (dry climates)
- saponification (wet climates)
saponification
hydrolyzed body fat; seen in decomposition within the first month in wet climates
what happens to remains within the first year?
- skeleton fully exposed
- sun bleaching
- moss and algae on bones
- rodent gnawing
- hard to give exact time of death
what happens to remains within the first decade?
- delamination
- rodent modification
- longitudinal cracks
- root growth through bones
what is the anatomical position?
- standing
- face forward
- arms at the side of body
- palms forward w/ thumbs on the outside
- toes forward
what are the three anatomical planes?
- sagital
- coronal
- transvers
sagital plane
- midline
- divides the body into symmetrical left and right halves
coronal plane
divides body into anterior and posterior halves
right angle of the sagital
transverse plane
- passes through at any moment at any height
- is perpendicular to the other planes
when viewing a subject, what are the directions in correlation to?
- right and left of the subject, not the observer
- if the area of description is on your left, you would state it was on the right because that is the position of the subject
superior
towards the head in a humanoid body
inferior
away from the head
posterior
toward the back, dorsal
anterior
toward the front, ventral
medial
toward the midline
lateral
away from the midline
proximal
- has to do with the limbs
- nearest the trunk
distal
- has to do with the limbs
- further from the trunk
palmar
palm side of the hand
plantar
sole of the foot. what touches the ground
dorsal
top of the foot, back of the hand
superficial
close to the surface
deep
away from the surface
bilateral
on both sides of the body
unilateral
on one side of the body
ipsilateral
occurring on the same side of the body
contralateral
occurring on opposite sides of the body