Classification of Trauma
Types of Trauma
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Medical doctors and surgeons may classify wounds differently
than ______________________________ and
_______________________
Mechanical Trauma
Occurs when the force exceeds mechanical or tensile
____________________________________________________
Resulting from _________ or _________________ force
_____________________________________________ of wound
may allow the forensic pathologist to determine if a sharp or blunt
object caused it
Judicious interpretations and caution are required because of the
flexible nature of many of the body’s tissues and the variability of
the violent force
Death from blunt and sharp trauma results from multiple
processes
Mechanical Trauma: Sharp Force
Refers to injuries caused by sharp implements, such as
____________________________________________________
Takes significantly ______________ force for a sharpened object
to cut or pierce tissue than what is required with a blunt object
Produce __________________ wounds – more depth than length
or width
Sharp trauma most commonly causes death from a fatal loss of
blood (exsanguination) when a major artery of the heart is
damaged
Mechanical Trauma: Blunt Force
Caused by dull or non-sharpened objects, such as
______________________________________________________
Blunt objects produce _______________________, or tears in
the tissue, typically the skin
Blunt trauma causes death most often when the
________________ has been severely damaged
__________________ – an accumulation of blood in the tissues
outside the normal blood vessels and is most often the result of
blunt impact
The blood pressures the tissues enough to break small blood
vessels in the tissues, and they leak blood into the surrounding area
The _______________ of the object may be transferred to the
skin and visualized by the blood welling up in the tissues
An extreme contusion, a _____________________, is a blood
tumor, or a contusion with more blood
___________________________________ – the projectile from
a discharged firearm produces a special kind of blunt force trauma
There are 4 major classes of gunshot wounds
_______________ (entrance)
_______________ (entrance)
________________ (entrance)
________________ exit
Contact (entrance) – distance is 0
Blackening of the skin; lacerations from escaping muzzle gases;
bright red coloration of the blood in wound from carbon monoxide
gases reacting to hemoglobin in blood (carboxyhemoglobin)
Intermediate (entrance) – 0.5cm-1m
Unburned gunpowder penetrate skin and burns it, causing small
red dots called stippling; the stippling pattern enlarges as the
muzzle-to-target distance increases
Distant (entrance) – >1m
Speed of gunpowder is insufficient to cause stippling at this
distance; lack blackening: no carboxyhemoglobin; circular defect
with abraded rim; distance intermediate
Shored exit
Skin is supported or shored by some material, such as tight
clothing, wall board, or wood, as bullet exits; may look very
similar to entrance GSW except pattern of shoring material (such
as the weave of cloth) may be transferred to skin as it expands
when bullet exits
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Chemical Trauma
Damage and death that results from the interaction of
__________________________________________
This is the domain of the ________________________
(discussed later)
If the damage from chemicals is ____________________l (acid
or alkaline burns) then it is still the responsibility of the pathologist
Thermal Trauma
Extreme __________ or _________ also may produce death
________________ – too much exposure to cold
________________– exposure to excessive heat
Either condition can interfere with the normal physiological
mechanisms that keep body temperature at about 98°F/37°C
In both cases, the forensic pathologist may encounter few signs at
autopsy that will indicate either of those mechanisms; more
commonly, external or __________________ factors, as well as
what is not found, may lead to this determination
Individuals in a vulnerable state of health – the sick, the very
elderly, or the very young – most often succumb to hypo- or
hyperthermia
Other factors may contribute, such as __________________,
which reduces sensitivity to cold and dilates (opens) the blood
vessels, speeding the cooling of the body
Hyperthermia deaths are common in elderly people in northern
cities and infants left in automobiles during the summer
The inside temperature of a closed car in the sun can exceed
140°F/60°C and can be fatal to an infant in __________ minutes
Thermal burns tend to be ________________; persons who die in
a fire do so generally because of a lack of oxygen
(______________) and the inhalation of combustion products, like
CO
The level of CO in the tissues can determine whether the person
was ________________________ when the fire burned him or her
A body from a burned building with 1 or 2% CO is presumed to
have been dead (or at least not breathing) at the time the fire
started.
True deaths from thermal injuries do occur due to either massive
tissue damage and/or swelling of the airway, causing
__________________
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Electrical Trauma
____________________ can cause death by a number of means
Circuits of alternating current (AC) at low voltages (<1,000V)
that cross the heart cause ______________ fibrillation, a random
quivering that does not pump the blood through the body properly
A person in ventricular fibrillation for even a few minutes cannot
be resuscitated
The heart fibrillates because the current is acting like a (faulty)
pacemaker
AC in the US alternates from positive to negative at 3,600
times/minute and at 2,500 times/minute in Europe; the heart can
beat only about __________ times/minute maximum
At high voltages, the amount of current causes the heart to stop
beating (it becomes _________________) pushing the heart into
_____________, a sustained contraction that is broken only when
the circuit is broken
Although the heart will generally start beating normally again,
high voltages produce severe __________ and _____________
damage within a fraction of a second