Introduction to Forensics Flashcards
What is the purpose of beetles Forensic Entomology?
Beetles come after flies
Early arrivers (rove and carrion beetles) eat the immature flies
Late arrivers (hide beetles) eat the dried cadaver flesh
in terms of the types of “mortises” what is the order from first to last?
Heart stops
Blood collects in dependent locations (Livor Mortis)
Body stiffens (Rigor Mortis)
Body cools (Algor Mortis)
How does body temperature and stiffness play a role in determining time of death?
warm + not stiff = less than three hours
warm + stiff = 3-8 hours
cold + stiff = 8-36 hours
cold + not stiff = greater than 36 hours
What are the three main types of decomposition?
Putrefactive
Adipocere Formation
Mummification
What is the role of the medical examiner?
To assign the cause of death
To render an opinion as to the matter of death
What is NOT the focus of a forensic examination?
The focus is NOT examinations of natural death (other than to rule out/observe discernible signs) or consider circumstances in terms of the probability of foul play/unnatural death, or contributions thereof
What are types of mechanical force injuries?
abrasions
contusions
incise wounds
gunshot wounds
blast injury
What are the types of thermal injuries?
burns
hyperthermia (heat cramps/exhaustion/stroke)
hypothermia
What are the types of electrical injuries?
What are two other categories of injuries?
varies
includes low and high intensity
ionizing radiation
atmospheric pressure (decompression p128R)
What are the pros and cons of ionization radiation?
Pros:
treat cancer
diagnostic imaging
therapeutic/diagnositc imaging
Cons:
fibrosis
mutagenesis
carcinogenesis
teratogenesis
What is the dose-related response to total body irradiation?
Exposure to radiation of large areas even in small doses can cause problems
Doses less than 1Sv produce minimal sx
higher doses can cause acute radiation syndromes
What are the sx of acute radiation syndromes?
damage to hematopoietic, GI and CNS
hematopoietic and lymphoid systems are EXTREMELY susceptible
How is cause of death documented on a death certificate?
(Immediate) cause of death (mechanism)
due to
(proximate) cause of death
Manner of death
Is cardiorespiratory arrest ever a legitimate cause of death?
No
What are the three types of blunt force trauma?
abrasion
contusion
laceration
What is the wounding formula?
W = E x 1/T x 1/A x K
K = modifying factors (elasticity of the striking object or tissue being injured)
E = Energy transferred (1/2MV^2)
T = Period of energy transfer (time)
A = Area of application of force
Define a Contusion
a bruise that results from hemorrhage into soft tissue due to rupture of subcutaneous blood vessels by blunt force injury
- Can be found on skin and within deep viscera, no break in epidermis/outer layer
The extent/severity of a contusion depends on what five factors?
- amount of force applied
- vascularity of tissue
- type of tissue injured (loose/thin)
- location of the tissue (over bone, etc)
- easy bruisability (old age, etc)
What color of a contusion is the best for aging an injury?
yellow-indicates that bruis is 18 hours or older
blue/purple/red do not help in aging
brown is just a mix of colors-not helpful
Define Abrasion
an abrasion is a wound in which the epidermis is injured. It is produced by friction scraping away epidermis or crushing of the epidermis by direct pressure or a blow tangential to the surface.
(typically oozes, doesn’t normally bleed; heals via scab)
What are the three types of abrasion?
- brush (grazing/sliding motion with rolled margins opposite direction of force)
- impact abrasion
- patterned abrasion (recapitulation of the surface appearance of the injurious agent)
Define stab
A stab wound is a sharp fore injury in which the depth of the wound track is greater than the length of the wound on the skin (deeper than longer). It is produced when an instrument with a pointed edge is thrust into the body or the body falls on the pointed edge.