PM changes

Question 1

Autolysis

Answer 1

• self-degradation of cells and tissues by the hydrolytic enzymes normally present in tissues
• occurs after somatic death due to total diffuse hypoxia
• cells degenerate as for hypoxic injury

Question 2

Putrefaction

Answer 2

• process by which post mortem bacteria break down tissues

- gives color, texture changes, gas production, odors

Question 3

Tissues with _____ concentration of proteolytic enzymes will autolyze the quickest. ex?

Answer 3

greater

ex. GI tract, pancreas, gall bladder

Question 4

The rate of decomposition depends on:

Answer 4

• cause of death
• environmental& body temp
• microbial flora (GI, bacterial fermentatioon continues after death –> gas & heat)

Question 5

Pulp kidneys in sheep

Answer 5

accelerated renal decomposition associated w/ Clostridium perfringens type D septicemia

Question 6

The presence of ____ is the most likely to be microscopically obscured by decomposition

Answer 6

cell injury (necrosis)

Question 7

Rigor Mortis

Answer 7

• contraction of the muscles after death
• begins 1-6hrs post death, persists 1-2d
• high heat & high activity before death accelerate the onset of rigor mortis
• due to depletion of ATP & inability of myosin to detach from actin binding site

Question 8

Livor Mortis

Answer 8

(aka hypostatic congestion)

• gravity will pull blood post death
• variation in color of tissues, skin, lung, kidneys
• in some areas the tissues will be more red and in other areas pale

Question 9

Post-mortem blood clotting

Answer 9

• occurs several hrs post death in the heart & vessels
• coagulopathies can delay or cause failure of blood to clot
• chicken fat clot appearance: due to separation of RBCs and clotted serum
• differentiate from pre-mortem clotting!!!

Question 10

Antemortem Clot (thrombus)

Answer 10

(before death)

• attached to vessel walls
• dry & dull
• lamellated
• friable

Question 11

Postmortem Clot

Answer 11

• unattached
• shiny & wet
• elastic
• perfect cast of vessel lumen

Question 12

Hemoglobin inbibition

Answer 12

• red staining of tissue, especially the intima of heart, arteries & veins
• Hb is released by lysed RBCs, penetrates the vessel wall, and extends into the adjacent tissues

Question 13

Bile inbibition

Answer 13

• bile in the gallbladder starts to penetrate the wall & stains the adjacent tissues- yellowish to greenish brown
• tissues stained are those in contact w/ the gall bladder: liver, intestines, diaphragm

Question 14

Bloat

Answer 14

• results from postmortem bacterial gas formation in the lumen of the GI tract
• herbivores Vs carnivores: herbivores bloat faster
• associated changes: rectal/vaginal prolapse, froth in trachea, ruptured viscera

Question 15

Common PM eye changes

Answer 15

• corneal opacity due to dehydration of cornea

- “cold cataracts”

Question 16

Pseudomelanosis

Answer 16

• refers to greenish-black discoloration of tissues post mortem
• decomposition of blood by bacterial action forming hydrogen sulfide w/ iron
• occurs soon after death
• commonly seen in tissues in contact w/ gut: kidney, liver, spleen, even the gut wall itself