Death - Agonal and Postmortem Changes

Death

Total and irreversible cessation of all metabolic processes

Nysten's Law

Directional occurrence of rigor from face to feet

Moribund

Dying condition; dying

Death Rattle

Rattling or gurgling sound produced by air passing through mucus in the lungs and air passages of a dying person, caused by a loss of throat reflex and accumulation of mucous

Death Struggle

Semi-convulsive twitches which often occur before death

Somatic Death

Death of the entire body

Agonal Period

Period immediately before somatic death. Sequence of steps as an expanding inability of the body to sustain the physiologic and metabolic process for life

Brain Death

Occurrences in a sequence of events that are a function of time without oxygen: 1. cerebral cortex, 2. midbrain, 3. brain stem

Biological Death

Irreversible somatic death - cessation of simple body processes, organs no longer function

Postmortem Cellular Death

Individual cells die, process may continue for hours after somatic death

Progression of Cellular Death

Brain and nervous cells -> 5 min
Muscle cells -> 3 hours
Cornea cells -> 6 hours
Blood cells -> 6 hours

Stages of Death

Agonal period
Somatic death
Clinical death
Brain death
Biological death
Postmortem cellular death

Necrobiosis

(Physiology) The normal degeneration and death of living cells (as in various epithelial cells); antemortem, physiological death of cells of the body followed by their replacement

Necrosis

Pathologic death of cells or tissue as a result of disease

Clinical Death

When spontaneous respiration and heartbeat irreversibly cease

Death Is a:

Process, not a moment in time

Changes During the Agonal Period

1. Temp changes
2. Circulatory changes
3. Moisture changes
4. Trans-location of microorganisms

Agonal Algor

Decrease in body temperature immediately before death

Agonal Fever

Increase in body temperature immediately before death

Agonal Hypostasis

Settling of blood into the dependent tissues before death. Due to the slowing of circulation, prior to death

Agonal Coagulation

Change from a fluid into a thickened mass, clotting and congealing, prior to death

Agonal Capillary Expansion

Opening of the pores in the walls of capillaries as the body attempts to get more oxygen to tissue and cells

Signs of Death

1. Cessation of respiration
2. Cessation of circulation
3. Muscular flaccidity
4. Changes in the eye: clouding of cornea, loss of luster and conjunctiva, flattening of the eyeball, dilated and unresponsive pupil
5. Postmortem lividity
6. Rigor mortis
7. Algor mortis
8. Decomp

Temperature Changes

Agonal algor
Agonal fever

Circulatory Changes

1. Agonal hypostasis
2. Agonal coagulation
3. Agonal capillary expansion

Moisture Changes

1. Agonal edema
2. Agonal dehydration

Agonal Edema

Increase in amount of moisture or fluids in tissues and body cavities due to disease or agonal capillary expansion

Agonal Dehydration

Decrease in amount of moisture or fluids in tissues and body cavities due to disease or capillary expansion

Translocation of Microorganisms

Movement of microorganisms from one area of the body to another due to capillary permeability changes
Results from organisms no longer being restricted
Movement established by hypostasis, entering circulatory system, or natural mobility features
Movement from intestinal areas to the blood vascular system
Also known as agonal translocation

Postmortem Changes

Physical changes
Chemical changes

Postmortem Physical Changes

Brought about by the 'forces of nature' and create changes in the physical state of the body and its tissues

Algor Mortis

Cooling of the body to the temperature of the surrounding environment

Hypostasis

Gravitation of blood and body fluids to dependent areas of the body

Liver Mortis

Postmortem intravascular blood discoloration brought about by hypostasis

Dehydration

Loss of moisture from the body's surface due to the surrounding atmosphere

Increased Viscosity of Blood

Thickening of blood primarily due to loss of liquid portion to tissue spaces

Endogenous Invasion of Microorganisms

Relocation of microorganisms in the body due to cessation of natural activities

Postmortem Chemical Changes

Brought about by chemical activity and result in the formation of new substances

Postmortem Caloricity

Temporary rise in body temperature after death

Change in Body pH

Shift from slightly alkaline to acidic during rigor, then back to alkaline for decomposition

Rigor Mortis

Natural body process causing postmortem stiffening of body muscles

Postmortem Stain

Color change due to heme seeping into body tissues from hemolysis

Decomposition

Compounds breaking down into simpler substances by enzymes

Intrinsic Factors

Factors originating within the body

Extrinsic Factors

Factors from the body's surrounding environment

Dependent Parts

Body parts closest to the ground

Contact Palor

Pale areas due to inhibited blood movement

Liver Mortis Also Known As

Postmortem Lividity or Cadaveric Lividity

Imbibition

Cells drawing moisture from surroundings

Sludge

Thick, viscous clumps formed by blood elements

2 Portions of Blood

Solid portion: made up of blood cells
Liquid portion: what the cells are suspended in

Clostridium Perfingens

Produces tissue gas
Embalmer's Nightmare

Metabolism

Sum of all chemical reactions within the cell
1. Anabolism - building phase
2. Catabolism - breakdown phase

Primary Flaccidity

Relaxation of muscles immediately after death

Secondary Flaccidity

Occurs after rigor mortis has left the body
Muscles return to a state of limpness and flaccidity

Autolysis

Digestion of cells or tissues by the cell's own enzymes

Amines

Organic compounds with an amino group; derivatives of ammonia

Ptomaines

Smelly breakdown products of protein putrefaction
- Alkaline substances
- Foul odor

Putrefaction

Decomposition of proteins by enzymes from anaerobic bacteria

Decay

Decomposition of proteins by enzymes from aerobic bacteria

Catalyst

Speeds up chemical reaction rate

Transition State

Chemical bonds break and new bonds form

Fermentation

Glucose breakdown process

Adipocere

Forms from postmortem body fats hydrolysis

Order of Decomp of Bodily Compounds

1. Carbs
2. Soft proteins
3. Fats
4. Hard proteins
5. Bones

Signs of Decomp

1. Color
2. Odor
3. Skin slip
4. Gases
5. Purge

First Color Change in Death

Greenish discoloration over right lower quadrant of abdomen

Desquamation (Skin Slip)

Outer skin layer weakens due to autolysis in deeper layers

Purge

Evacuation of gases, liquids, and semisolids from body orifice

Expert Tests of Death

Stethoscope, Ophthalmoscope, Electroencephalogram, Electrocardiogram, Evoked Response

Inexpert Tests of Death

Listen for Breath/Heart Beat