Lesson 3: Agonal Changes, Postmortem Changes & Signs of Decomposition

Question 1

Physical Postmortem Changes

Answer 1

algor mortis, dehydration, hypostasis, livor mortis, increased blood viscosity, endogenous invasion of microorganisms. Physical changes involve rearrangement of molecules and do not produce new by-products or compounds, change in physical condition of body due to forces of nature

Question 2

Chemical Postmortem Changes

Answer 2

postmortem caloricity, changes in pH, rigor mortis, postmortem stain, and decomposition, these chemical changes involve chemical activity, and new compounds being produced by molecule rearrangement

Question 3

Hypostasis

Answer 3

gravitation of blood and body fluids to dependent (lower) areas of body, causes livor mortis, will lead to postmortem stain, causes edema in dependent body tissues

Question 4

Algor Mortis

Answer 4

cooling of the body to temperature of surrounding environment, slows onset of rigor mortis and decomposition, keeps blood in liquid state, increases livor mortis and postmortem stain

Question 5

Dehydration

Answer 5

loss of moisture from surface of body into surrounding atmosphere, increases blood viscosity, discolors skin tissue, causes wrinkling and shriveling, can slow decomposition

Question 6

Livor Mortis

Answer 6

intravascular blood discoloration to dependent areas of body as a result of hypostasis, can be removed with arterial injection and gravitation, can be made permanent with stong arterial chemicals, will lead to postmortem stain

Question 7

Endogenous Invasion of Microorganisms

Answer 7

relocation of microorganisms in body due to body’s inability to continue natural and metabolic activities, accelerates decomposition, creates unsanitary conditions for embalmer

Question 8

Increase in Blood Viscosity

Answer 8

Thickening of blood due to loss of moisture from vascular system, blood is thicker and coagulated, causes poor fluid distribution and blood drainage

Question 9

Rigor Mortis

Answer 9

Temporary stiffening of body muscles by natural processes, causes extravascular resistance, difficulty in body positioning and setting of features, can lead to tissue distension, preservative chemical does not absorb well into tissues, increases need for more preservative, pH level unsuitable for preservation, can cause false sense of preservation

Question 10

Postmortem Caloricity

Answer 10

temporary rise in temperature of body after death, accelerates rigor mortis cycle, accelerates decomposition

Question 11

Postmortem Stain

Answer 11

Extravascular blood discoloration where hemolysis causes blood pigment to stain the tissues, cannot be cleared with arterial injection, body requires more preservative, indicates longer postmortem interval

Question 12

Decomposition

Answer 12

separation of compounds into simpler substances, causes poor distribution, causes tissue distension upon injection, creates need for more preservative, causes discolorations, gases, odor, skin slip, and purge

Question 13

Shifts in pH

Answer 13

after death body goes acidic during rigor mortis then alkaline during decomposition, creates environment not suitable for preservative to react as effectively with tissue cells

Question 14

Problems for embalmers due to rigor mortis

Answer 14

1. extravascular resistance
2. problems with body positioning and feature setting
3. tissue swelling during arterial injection
4. acidic pH not suitable for reaction of preservative chemical with tissue cells
5. reduces absorption of preservative
6. can create false signs of preservation
7. can contribute to blotchy colorations of tissues if dyes are used
8. increases demand for preservative

Question 15

Somatic Death

Answer 15

death of whole body, body loses its ability to sustain physiologic and metabolic activity, somatic death includes clinical death, brain death, biological death, and cellular death

Question 16

if the body is cooled quickly what would you expect to see?

Answer 16

livor mortis and postmortem stain would be increased because quick cooling of the body keeps blood in a liquid state

Question 17

what is the normal body pH and best for reaction with preservatives?

Answer 17

pH of 7-7.4

Question 18

how many hours after death does postmortem staining occur?

Answer 18

6-10 hours

Question 19

how many hours after death does rigor mortis naturally leave a body?

Answer 19

36-72 hours

Question 20

how soon after death can livor mortis be observed?

Answer 20

30-90 minutes

Question 21

how many hours after death is rigor mortis first observed?

Answer 21

2-4 hours

Question 22

how many hours after clinical death may cells continue to live before cellular death is complete?

Answer 22

6 hours

Question 23

within how many hours of death will the migration and invasion of pathogenic microorganisms from the colon to the heart, lungs, urinary tract, bladder, and the base of the brain occur?

Answer 23

4-8 hours

Question 24

Why does the body shift to an alkaline pH during decomposition?

Answer 24

A build-up of ammonia by-products from decomposition change the pH to alkaline

Question 25

why does the body shift to an acidic pH during rigor mortis?

Answer 25

A build-up of lactic acid which causes the pH to become acidic as rigor mortis goes on