Postmortem Changes and Non-Lesions

Question 1

Autolysis

Answer 1

-Degradation of cells and tissues by the hydrolytic enzymes normally present in tissues

Question 2

When does autolysis occur?

Answer 2

After somatic death due to total diffuse hypoxia

Question 3

Putrefaction

Answer 3

Process by which post mortem bacteria break down tissues

Question 4

Signs of putrefaction?

Answer 4

Color, texture changes, gas production, odors

Question 5

Which tissues will utilize the quickest? Name them…

Answer 5

The tissues that have the greatest concentration of proteolytic enzymes.
1. GI tract 2. Pancreas 3. Gall bladder 4. Other soft tissues

Question 6

Rate of decomposition depends on what? (3)

Answer 6

1. Cause of death 2. Environmental and body temp. 3. microbial flora (bacterial fermentation continues = gas and heat)

Question 7

When does rigor mortis begin and how long can it last?

Answer 7

begins 1-6 hours post death and persists 1-2 days

Question 8

Why does rigor mortis occur and what can effect the onset of it?

Answer 8

It is due to a depletion of ATP and inability of myosin to detach from actin binding site and if the animal was very active before death (high heat) it can accelerate the onset of rigor mortis

Question 9

What is Liver Mortis (hypostatic congestion)?

Answer 9

Gravity pulls the blood post death (see in fair skinned animals, the lungs and kidney)

Question 10

When does post-mortem clotting occur?

Answer 10

Several hours post death both in the heart and vessels

Question 11

Coagulopathies

Answer 11

delay or cause failure of blood to clot

Question 12

What is the chicken fat clot appearance due to?

Answer 12

separation of RBCs and clotted serum

Question 13

What are the characteristics of a premortem clot?

Answer 13

1. Attached to vessel walls
2. dry and dull
3. lamellated
4. friable

Question 14

Characteristics of a postmortem clot?

Answer 14

1. Unattached
2. Shiny and wet
3. Elastic
4. Perfect cast of vessel lumen

Question 15

What is hemoglobin imbibition?

Answer 15

Red staining of tissues which is caused by Hb released from lysed RBCs and penetrates the vessel walls which extends into the adjacent tissues

Question 16

What is bile imbibition? What tissues are stained?

Answer 16

• Bile in the gallbladder starts to penetrate the wall and stains the adjacent tissues (yellow to green brown)
• Liver, intestines, diaphragm

Question 17

If ruminal tympany occurs what will you see?

Answer 17

An esophageal “bloat line”

Question 18

What PM changes will you see with the eye?

Answer 18

Corneal opacity which is due to dehydration of the cornea

Question 19

Pseudomelanosis

Answer 19

green to black discoloration of tissues post mortem due to decomposition of blood by bacteria which forms hydrogen sulfide with iron

Question 20

When and where is pseudomelanosis seen?

Answer 20

Soon after death and can be seen in tissues in contact with the gut
kidney, liver, spleen, and the gut wall itself