• breathing cease
• heart stop, no pulse
• pallor (cessation of circulation)
• muscles begin to relax
• body fluids released
  • gastric conntents
  • urine, semen
  • feces
• blood begins to coagulate

algor mortis

livor mortis

rigor mortis

• cooling of body to equilibrate with surrounding temperature
• most common methoss are rectal and hepatic core
• most useful in first 10-12 hrs and when envir. temp. is 70-75
• average coolin 1.5 degress per hour
• affected by body temp before death
  • what is normal for the person
  • illness/infection
  • activity (exercise)
• affected by age and muscle mass
• affected by clothing
• affected by envir. conditions
  • surrounding temp
  • surface temp
  • artifical changes to temp

• postmortem hypostasis or settlin of blood
• due to combined effects of cessation of circ. function, lack of bp, effects of gravity
• blood settles in dep. aspects
• skin become darker where blood has settled
• usually is dark purple or dark blue in color
• color dep. on skin pigmentation and compounds found in blood
• onset immediately at time of death (when cardiac func. cease)
  • has been noted in live patients in shock
• usually apparent in 30 min-1 hr
• easliry observed within 4 hours
• blanches when presssed in early stage
• fully fixed within 6-12 hrs
• with body mov't of body will become apparent in other dependent locations prior to becoming fixed

• begin within 1-3 hrs
• become fully dev. within 10-12 hrs
• remains for 24-36 hrs before becoming flacid
• early/mild phase- small muscle first
• mild/moderate- larger muscles
  • elbows, knees
  • moved or broken with gentle moderate force
• fully/complete- largest muscles
  • upper arm, thighs,
  • need greater force to moe, mnay be impossible to move
• must be cautious to see if rigor mortis is dev. or reversing

• body temp before death
  • illness
  • activity
• affected by age and muscle mass
  • elderly and children dont show as much rigor due to less muscle mass
• affected by body habitis
  • obese people show rigor mortis later

• decomp./putrefaction
• mummification
• skeletonization
• saponificatoin/adipocere

Envir. dep. that mask or mimic trauma

• stage one
  • enzymes release as part of cellular death and breakdown
  • bact. released from stomach and intestines
  • blue-green discol. of abdomen
  • occurs within 24-36 hrs
• stage two
  • veining or marbiling notied
  • occurs 30-48 hrs
• stage three
  • gasses released into surroundin tissues by bacterial activity
  • body bloats
  • gas and fluid filled blisters noted
  • occurs 36-48 hrs
  • occurs simultaneously with discoloration
• stage four
  • loosening of hair, nails, and shedding of skin
  • occurs within 4-7 days

YOU DONT DEV. DISEASE, IT IS JUST BODY BREAK DOWN

• drying of fluids and tissues of body
• interupts decomp. process
• skin becomes letherly in feel, appearance
• requires dry, arid conditions, good ventilation, absence of insects and animals
• seen in early stages within one week
• noted first on exposed areas, face, fingers, toes
• completed within 3-6 months
• relatively little odor

• remove soft tissue from skeletal structure
• can be due to decomposition
• dependent upon envir. conditions, location/storage of body
• accelerated by insect, animal activity
• dep. on types of insects and animals located in the region and season
• usually noted on exposed areas first
• can occur independent of decomp. if insects and animals very active

• first- redness of skin
• second- blistering with destruction of dermis
• third- destruction of tissues below the skin
• fourth- charring

• cant really predict mortality
• age + % total body surface area (TBSA)
• full thickness burns over 40% TBSA
• burns of face, hands, feet, genitalia, major joints
• burns, trauma and or debilitating diseases

• CO Hb levels over 10% indicates person was alive
• low levels may be seen in flash fires

• low voltage current- reddish blistering area, or irreg. chalky white lesion with raised borders or central crater
• high voltage current- severe burns with charring
• no burns- current enters through broad area with minimal resistance

• abrasion
• contusion
• laceration
• avulsion

• injury to the skin in which there is removal of epidermis by friction against a rough surface or destruction of the epidermis by compression
• types
  • scrape, brush abbrasions
  • impact abbrasions
  • patterned

• bruise, area of hemorrhage into soft tissue due to rupture of blood vessels caused by blunt trauma

• lacerations- tissue bridging
• cut- sharp margins, no tissue bridging

• form of laceration
• force impacting body is at an oblique or tangential angle to the skin, ripping the skin and soft tissue off the underlyin fascia or bone

• abrasion
• incision
• laceration
• contusion
• avulsion
• crush
• fractures of bone

• entrance gunshot wounds
• exit gunshot wounds
• indicators of distance
  • muzzle imprint
  • soot deposition
  • gunpoder stippling

• gyroscopic effect- the spin stabilizes bullet in air
• fire one projectile at a time
• class char.- typical of group of weapon
• ind. char.- typical of specific barrel

• the more kinetic energy lost, the greater the damage
• due to tumbling action

• entrance has fine abrasion punch out look
• exit looks more irregular and a tear

• close range
  • unburned powder particles in skin (aka tatooing/stippling)
  • deposits of soot on skin
• long range
  • demonstrate clean margins
  • round, oval
  • no evidence of stippling

• depth of wounds greater than the length on the skin

• stab wounds (greater in depth than length)
• cuts (incised wounds)

• wound char (single vs. double edge)
• need to know wound path
• direction of wound path
• approximate depth of wound

• weapons used
• direction of thrust
• movement of victim and or assailant
• char. of skin (Langer lines)

• elastic fibers in dermis
• wounds parallel to these lines tend to be slit-like
• wounds perpendicular to these lines are gaping

• wound longer on skin that deep
• wound doesn't give us info on type of weapon used

• characteristics
  • rectal temp. of 105-106
  • ability to cool body cannot compensate for heat load
• most common cause- exposure ot high envir. temp.

• muscle cramps due to electrolyte loss
• dehyd.
  • hypovol
  • skin pale
  • cold
  • sweaty
  • faint, then recover

• insensible heat loss, loss of moisture not by means of sweating
• sweating, the most important of two mechanisms
  • progressively sweat more and more upon exposure to hot weather for several weeks (trying to comp.)

• very young, elderly
• dehyd.
• high level of humidity
• CV, NS disease
• drugs that impair sweating (antidep., antihis.) or increase body heat prod. (crack, ephedrine)

• cherry red lividity
• Wishnevsky gastric lesions
  • superficial gastric mucosal
• ulcerations

• rectal temp below 95
• heat loss exceed heat prod.
• most common cause- exposure to low envir. temp.

• social factor, homelessness
• drug use, alcohol
• very young, elderly
• debiliting CV disease (lower temp. leads to increase risk of coronary events)

• terminal burrowing
• paradoxical undressing (due to paralysis of thermoregulatory mechanism with feeling of warmth)

• hemorrhage (hematoma, tamponade, exsanguination), infection, shock
• these lead to nephrosis

High velocity missles can induce shock waves that cause viscera to rupture

• simple (2 pieces)
• comminuted (many frag.)
• compound (bone pierce skin)
• pathological (bone weakened via prior disease)

Solid visceral organs can fracture due to blunt force or shock waves

• histopathology
  • necrosis of cardiac, skel muscle
  • DIC
  • nephrosis
• signs
  • red
  • dry skin
  • peripheral vasodilation

• local
  • frostbite
  • trench foot
• systemic

• cell death occurs when ice crystals form and between cells cause cell rupture
• blood may sludge
  • this constricts small vessels causing infactrion
  • wet, dry gangrene may follow

• slow chilling causing vasoconstriction and increased vascular permeability
• leads to edema and eventually tissue necrosis

• vasoconstrict, hemoconc., steffeining of muscle joints
• shallow breathing and confusion leads to loss of consciousness/necrosis (freezing) and death with core body temp. less than 90
  • due to bradycardia and arrhythmia
  • occasional peripheral vasodil. and hypermeia
• eventually, circulatory failure, coma, and death often without apparent tissue necrosis

• if through brain, impulses from vital centers may be interrupted (resp., cardiac arrest)
• through heart, cardiac arrest may cause death

• laryngeal and pulm. edema
• anoxia
• pneumonitis (ARDS)

EVENTUAL LUNG FIBROSIS

• coagulative necrosis
• collagen hyalinization
• carbon often deposited on surface

• neurogenic shock, loss of plasma, leading to hypovolemic shock, infection
• causes endotoxic shock
• hemolysis leading to nephrosis and stress ulcers (Curling ulcers)