Post Mortem Changes Flashcards

Question

Features of cadaveric spasm

Answer 1

``` Rare, instantaneous form of rigor Stiffening occurs at moment of death and persists into period of rigor mortis Violent death with extreme emotion Affects muscles groups -> intense grip Records last act of life - weapon in battle/suicide - weeds in drowning - vegetation in mountain fall ```

Answer 2

Warm and flaccid = dead < 3 hours Warm and stiff = dead 3-8 hours Cold and stiff = dead 8-36 hours Cold and flaccid = dead > 36 hours

Answer 3

Gravitational settling of liquid blood in capillaries Seen as purple discolouration in dependent areas Horizontal fluid level Contact pallor where vessels are compressed Punctate haemorrhage within intense lividity - burst blood vessels due to high pressure Easily confused with bruising Poor indicator of PMI Good indicator of body position since death

Answer 4

Blood begins to settle at death Red patches often withing 30 mins - up to 2 hours Well formed by 4 hours Max intensity at 8-12 hours Fixed after 12 hours Delayed or minimal with anaemia of haemorrhage

Answer 5

Fixation = no longer blanches on fingertip pressure Fixation is relative Movement before 6 hours - before well formed - primary pattern is unfixed and fades away - new secondary pattern forms Movement after 10 hours - well formed but not fully fixed - primary pattern fixed enough to remain - enough fluid blood to form new secondary pattern - gives dual distribution - front and back Movement after 24 hours - well formed and fixed - primary pattern fixed and remains - not enough fluid blood to created new secondary pattern

Answer 6

``` Bright pink - refrigeration - hypothermia Cherry pink - carbon monoxide Chocolate brown - methaemoglobin (chlorate) Scarlet - cyanide ```

Answer 7

``` Heart - mimics MI Lungs - mimics pneumonia Intestines - mimics infarction ```

Answer 8

``` Maceration - sterile autolysis in foetus Wet putrefaction - commensal flora Skeletonisation Mummification - dry conditions Adipocere - wet conditions ```

Answer 9

Destruction of tissues by body's own bacteria and enzymes Bacteria spread from gut and resp tract to other tissues via blood stream Rate depends on environmental temp - optimal at 21-38°C

Answer 10

``` Most present in GIT and URT - coliforms - clostridia - anaerobic bacilli - micrococci Exogenous bacteria introduced by wounds, insects, animals Spread via bloodstream ```

Answer 11

``` Hastened by - slow initial cooling - clothing, bedding - environmental temp - humidity - obesity - terminal septicaemia - wounds Delayed by - rapid initial cooling - refrigeration - fire - heat fixation - blood loss - embalming - immersion - burial ```

Answer 12

Green discolouration of abdomen RIF - 2 days - bacteria from large intestine closest to skin Passage of rigor Marbling - few days Skin blisters and slippage Gas production and bloating - week - methane, H2, H2S, NH3 - ptomaines - putrescine, cadaverine Loss of hair and nails Liquefaction - months Skeletonisation - years, days if warm and insects

Answer 13

Discolouration of stomach and intestines Haemolytic staining of blood vessels and airways Heart dilated and flabby Liver and brain softened and honeycombed by gas Spleen softened and mushy Uterus and prostate slow to putrefy - helps identification

Answer 14

Useful if time of last meal known Food remains in stomach for 3-4 hours Rates of emptying and digestion variable Food may persist undigested for several days following severe trauma

Answer 15

``` Flies attracted by smell - calliphora vicina - bluebottle - lucilia caesar - greenbottle Lay eggs in moist areas - eyes, nose, mouth, perineum, wounds Young larvae feed on tissues Older larvae leave to pupate and hatch May be several generations on body Succession of beetles feed on larvae and tissues ```

Answer 16

Moist environment Hydrolysis of fat into waxy, pale, soapy substance with sweetish rancid odour Clostridium welchii important in process Released fatty acids inhibit other bacteria Takes weeks or months to develop Seen in cheeks, breasts, buttocks Affords degree of preservation to body

Answer 17

``` Desiccation of tissues in dry, warm conditions Takes weeks Skin becomes dry, leathery and shrunken Internal organs decomposed or preserved More common in infants that adults Affords good preservation ```