Lesson 3.1 Death Defined - Embalming 1

Inexpert Test: Pulse

Digital pressure to check for pulse beat.

Agonal Period

During the agonal period the body is said to be moribund, a dying condition, or dying. Occurs prior to the point in the process where the body loses its ability to sustain vital physiologic and metabolic activities. Might be quite short, as would be the case in an accident where death resulted from sudden, fatal injuries. Or, the process might take place over an extended period of time, as would be the case in a death caused by chronic illness. Whether the agonal period is long or short, at a given point in the process, the body can no longer function as a whole organism.

Hemoglobin Molecules

Each red blood cell contains several million hemoglobin molecules. Hemolysis releases the hemoglobin, which rapidly decomposes into globin and heme. The heme then passes through the walls and pores of the capillaries and moves into the tissue spaces where it stains the tissue a reddish color. This reddish stain is permanently fixed, because it is now extravascular.

Purge

Evacuation of gases, liquids, and semisolids from a natural body orifice. In decomposition, purge is generally caused by the buildup of pressure from gas formed in the abdomen.

Primary Flaccidity

After rigor mortis passes, it does not recur. Usually, the muscles are relaxed as death occurs. This is called primary flaccidity.

Agonal Edema

An increase in the amount of moisture, or fluids, in the tissues and the body cavities. It may result from disease processes or from agonal capillary expansion.

Contact Pallor

Areas where blood movement has been inhibited.

Sludge

As dehydration occurs, the blood will become increasingly viscous. Eventually the formed elements of the blood will stick together in clumps.

Hydrolysis

Been called the single most important factor in the initiation of decomposition. It is a chemical reaction in which the chemical bonds of a substance are split by the addition or taking up of water.

Agonal Dehydration

Decrease in the amount of moisture, or fluids, in the tissues and the body cavities. It may result from disease processes or from agonal capillary expansion.

How long after blood has settled will discoloration begin to appear?

1/2 to 2 hours after death.

Expert Test: Electrocardiogram

A record of the electrical activity of the heart.

Expert Test: Electroencephalogram

A record of the electrical activity of the heart.

Inexpert Test: Ammonia Injection Test

A small amount of ammonia is injected subcutaneously. If there is a reddish reaction in the skin, it indicates that life is present.

Catalyst

A substance that speeds up the rate of a chemical reaction without itself being permanently altered in the reaction. In every chemical reaction there is a transition state, where chemical bonds of reactants are broken down and new chemical bonds are formed.

Imbibition

A third factor that works in conjunction with the gravitation of liquids. Imbibition is the ability of the cells to draw moisture from the surrounding areas into themselves. The areas where the liquids move to can become edematous (postmortem edema).

Inexpert Test: Ligature Test

Finger is ligated with string or a rubber band. If the litigation causes swelling or discoloration, it indicates that circulation of blood is still occurring.

Increase in blood viscosity

Physical Change Thickening of the blood after death caused primarily by the loss of the liquid portion of the blood to the tissue spaces.

Necrobiosis

Physiologic, or natural, death of cells as they complete their life cycles.

What is one of the last organ systems to decompose?

Vascular system, even in advanced decomposition it would be possible to inject some preservative chemicals in an attempt to slow decomposition and control odor.

What happens when hydrolysis occurs?

Water is broken apart, another compound is broken apart, and new products are formed. The process requires (1) water (2) catalysts, and (3) compounds with which to react. Hydrolysis is the first chemical reaction in the putrefactive process. During hydrolysis large protein molecules are broken down into smaller fragments called - proteoses, peptones, and polypeptides.

Gravitation or Hypostasis

When the blood and body fluids in the physical movement of body fluids to dependent regions of the body. The higher areas where liquids move from are likely to become dehydrated. Conversely, the lower areas where the liquids are flowing to may become engorged, a condition called postmortem edema.

Secondary Flaccidity

Within 36 to 72 hours, rigor mortis passes naturally from an un-embalmed body. In this phase, there will be a greater demand for preservatives because muscle protein has been broken down to some extent. Rigor results from the body's inability to re-synthesize ATP that causes the muscle proteins to lock together and form an insoluble protein. Rigor marks the end of muscle cell life and is generally observed in the average body 2 to 4 hours after death.

What are the two factors that play an important role in the degree of intensity of livor mortis?

- Blood Volume - Blood Viscosity

List the inexpert tests for death

- Ligature test - Ammonia injection test - Pulse - Listening for respiration or heart beat

What are the postmortem chemical changes

- Postmortem caloricity - Postmortem stain - Shift in pH - Rigor mortis - Decomposition

List the expert tests for death

- Stethoscope - Ophthalmoscope - Electroencephalogram - Electrocardiogram - Evoked Response

List the postmortem physical changes

1. Algor Mortis 2. Hypostasis 3. Livor Mortis 4. Dehydration 5. Increased viscosity of the blood 6. Endogenous invasion of microorganisms These changes are brought about by the stoppage of blood circulation, gravity, and surface evaporations.

Algor Mortis: Extrinsic Factors

1. Body coverings - include clothing or other coverings that protect the skin from direct exposure to the environment 2. Surrounding environment

What is the order of decomposition of the body compounds?

1. Carbohydrates 2. Soft Proteins 3. Fats 4. Hard Proteins 5. Bones

Signs of Death

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

Postmortem factors that contribute to the translocation of endogenous microflora

1. Chemical and physical changes 2. Movement and positional changes of the body 3. Passive recirculation of blood from contaminated body sites 4. Thrombus fragmentation and relocation 5. The inherent true mobility of many of the intestinal bacilli

How can the effect of Agonal Period changes be categorized?

1. Temperature of the body 2. Ability of the body to circulate blood 3. Moisture content of the tissues 4. Translocation of microorganisms within the body

Algor Mortis: Intrinsic Factors

1. The ratio of surface area of the body to body mass. 2. Body temperature at the time of death 3. Combinations of the effects of the ratio of surface area to body mass and body temperature at the time of death.

Decomposition of Lipids

Body fats are broken down by hydrolysis that occurs in the presence of enzymes called lipase. The products of this breakdown are glycerol and fatty acids. These by-products do not significantly affect the embalming operations because they do not change the alkaline environment, nor do they give off any bad odors.

Chemical Changes

Brought about by chemical activity. As a result, new substances are formed. For example, there are autolytic processes taking place in the body during the postmortem period. These processes are largely dependent on autolytic enzymes, which break tissues by stimulating chemical reactions between substances found in the tissues. As existing substances react chemically with one another, new compositions are formed.

Physical Changes

Brought about by the forces of nature. Forces of nature act on the body in such a way as to create changes in the physical state of the body or body tissues. These physical changes, however, do not create chemical by-products or change the chemical composition of the body. The force of gravity, for example, may move blood from one place to another in the body.

Change in body pH

Chemical Change Change in body tissues from slightly alkaline in life (pH 7.38-7.40) to acid (pH 6.0-5.5) during rigor, then a return to alkaline in decomposition.

Postmortem Stain

Chemical Change Extravascular color change brought about by hemolysis where liberated hematin seeps through the capillary walls and into the body tissues; this type of stain cannot be removed by arterial injection and venous drainage. After death, the blood gravitates into the vessels of the dependent areas of the body. The pooling of blood in the dependent areas of the body results in an intravascular discoloration called livor mortis.

Decomposition

Chemical Change Separation of compounds into simpler substances by the action of bacterial and/or autolytic enzymes.

Rigor Mortis

Chemical Change Temporary postmortem stiffening of body muscles by natural body processes. Once the condition passes, it does not recur. Usually, the muscles are relaxed as death occurs.

Postmortem caloricity

Chemical Change Temporary rise in body temperature after death.

A condition which may be mistaken for rigor mortis is called what?

Cold Stiffening - it is due to solidification of body fats and tissues when the body is exposed to cold temperatures.

Adipocere

Commonly known as "grave wax" is thought to be composed of fatty acids and appears in bodies that have been dead for an extended period of time (3 months or longer).

Agonal Algor

Cooling or decrease of the body temperature prior to death. This is often seen in the death of elderly patients, especially when death occurs slowly. Metabolism has slowed in these individuals and, no doubt, the circulatory system has slowed.

Signs of Decomposition

Five classic signs of decomposition. 1. Color 2. Odor 3. Skin slip 4. Gases 5. Purges Decomposition in the dead human body is not a uniform process. It may be present in one location and absent in another. Decomposition can also be present without all five "signs" being present at the same time. For example, a body may evidence decomposition by skin slip and color changes but exhibit no abdominal gases or purge.

Endogenous Invasion (Translocation) of Microorganisms

Following somatic or functional death, normally structurally intact epithelial, fascial and other tissue barriers undergo a loss of structural integrity and permit the body wide translocation and distribution of systemic microflora and create alternate body fluid and body tissue reservoir sites of host contamination. All body fluids and body tissues may become reservoirs of infectious agents within a relatively short postmortem interval.

Shifts in Body pH

In chemistry, degrees of acidity or alkalinity of a substance are expressed in pH values. The neutral point, where a solution would be neither acid nor alkaline, is pH 7. Increasing acidity is expressed as a number less than 7 and increasing alkalinity as a number greater than 7. Maximum acidity is pH 0 and maximum alkalinity is pH 14. Because each unit on the scale represents a logarithm, there is a 10-fold difference between each unit. After death occurs, the oxygen is gradually used up, and the lactic acid is no longer inhibited and begins to accumulate in the muscle tissues. The buildup of acid occurs during the first hours after death (approximately the first 3 hours). This cycle is closely and directly related to the cycle of rigor mortis. The pH will drop to an acid level of approximately 6.0 and has been recorded as low as 5.5.

Agonal Fever

Increase of the body temperature just prior to death. Often seen in persons with infection, toxemia, or certain types of poisoning. Frequently, elevated temperature can stimulate microbial growth.

Postmortem Cellular Death

Individual cells can sustain metabolic activity by utilizing available stores of essential elements. At some point, individual cells will use up stored elements, or will be overcome by autolytic processes, and die. Process during which individual cells die. May take a matter of hours depending on numerous variables.

Expert Test: Ophthalmoscope

Instrument used to examine the interior of the eye, especially the retina. Instrument would be used to examine the blood vessels in the retina for signs of circulating blood. Because it is a light source, it could also be used to detect responses in the pupils of the eyes.

Expert Test: Stethoscope

Instrument used to mediate sounds produced in the body. Would be used to listen for sounds of respiration or cardiac activity.

Postmortem Caloricity

Metabolism is defined as the sum of all of the chemical reactions that occur within a cell. It is dependent on oxygen. There are two phases of metabolism (1) anabolism, the building phase and (2) catabolism, the breakdown phase that releases heat and energy. After death occurs, the cells may still have a supply of oxygen and, therefore, metabolism will continue.

Expert Test: Evoked Response

Method of testing the function of certain sense organs, even if the subject is unconscious or uncooperative. For example, in a living patient, an auditory evoked response will appear on an electroencephalograph if sound reaches the brain.

Agonal Coagulation

Occurs as the circulation of blood slows and the formed elements of the blood begin to clot and congeal.

Brain Death

Occurs in a sequence of events that are a function of time without oxygen. The first part of the brain to die, usually in 5 or 6 minutes, is the cerebral cortex. Next the midbrain dies, followed by the brain stem.

Clinical Death

Occurs when spontaneous respiration and heartbeat cease. It is during this time that the person can be resuscitated and, therefore, this is the reversible phase of the somatic death process. If respiration and heartbeat are not reestablished, brain death will result. Occurs when spontaneous respiration and heartbeat irreversibly cease.

Somatic Death

Once the body loses its ability to sustain physiologic and metabolic activity, somatic death occurs. Death of the entire body. It proceeds in an orderly progression from clinical death to brain death, then to biological death, and finally to postmortem cellular death.

Agonal Capillary Expansion

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

Amines

Organic compounds that are considered to be derivatives of ammonia. Amines such as skatole, indole, cadaverine, and putrescine are alkaline substances that have a foul odor. They are commonly called ptomaines.

Biological Death

Period in the process where simple life processes of the various organs and tissues of the body begin to cease. Irreversible phase of somatic death and represents the cessation of simple body processes. The organs no longer function.

Hypostasis

Physical Change Gravitation of blood and bodily fluids to dependent areas of the body. Process by which blood settles, as a result gravitational movement within the vessels, to the dependent, or lowers parts of the body. The dependent parts of the body would be those parts closer to the ground. The designation of dependent parts would change depending on the position of the body.

Dehydration

Physical Change Loss of moisture from the surface of the body to the surrounding atmosphere. Loss of water from body tissues and fluids by surface evaporation. Surface evaporation results from the passage of air or air currents over the surface of the body. It is to the embalmer's advantage to have the body covered or in some way protected against the effects of the air currents.

Algor Mortis

Physical Change Postmortem cooling of the body. Cooling of the body to the temperature of the surrounding environment. Rapid cooling of the body by refrigeration or natural means helps to slow the onset of rigor mortis, slow the onset of decomposition, and keep the blood in a liquid state. These are all advantageous for embalming.

Livor Mortis

Physical Change Postmortem intravascular blood discoloration brought about the presence of blood in the dependent surface vessels of the body. Occurs as a result of hypostasis. Also known as postmortem lividity or cadaveric lividity. Discoloration may first be noticed as dull reddish patches. As it becomes more established it can take on a deep reddish-blue appearance. Categorized as an intravascular discoloration, meaning that it occurs within the blood vascular system and can be reduced or removed during the embalming process as embalming solution flushes the pooled blood from the area.

Endogenous invasion of microorganisms

Physical Change Relocation of microorganisms in the body as a result of the cessation of natural and metabolic activities which, in life, keep the organisms in check.

Nysten's Law

Pierre Nysten (1774-1817) he was a French pediatrician. Rigor Morits was first demonstrated in small muscles such as the jaw and gradually it becomes evident in large muscle groups. Thus it appears to begin in the involuntary muscles of the eye, then moves to the jaw and face, neck, upper extremities, trunk, and lower extremities. This directional occurrence of rigor mortis from the face to the feet is what is known as Nysten's Law.

Inexpert Test: Listening for heartbeat

Placing your ear over the chest of the individual.

Fermentation

Process by which glucose breaks down.

Putrefaction

Protein decomposition. Some authorities restrict the term putrefaction to the decomposition of proteins by anaerobic bacteria (those able to live without oxygen) and use the term decay for the decomposition of proteins by aerobic bacteria (those that need oxygen to live).

Peptide Bond or Peptide Linkage

Proteins are also an essential element from the standpoint of embalming because successful embalming is achieved by establishing cross-linkages between proteins of the body and proteins of microorganisms. Proteins are large molecules that contain elements of carbon, hydrogen, oxygen, and nitrogen. This is the chemical bond that links the two proteins together. It is possible for many proteins to link together. During decomposition, the protein chains break down. If the breakdown is caused by catalytic enzymes, the enzymes are called proteases.

Necrosis

Refers to the pathologic death of body cells as a result of disease processes (gangrene or decubitus ulcers)

Viscosity

Refers to the thickness of a liquid. The blood is composed of two portions: (1) a "solid" portion made up of the various groups of blood cells and (2) a "liquid" portion in which the cells are suspended. After death, blood has a tendency to increase in viscosity and thicken.

Death Rattle

Respiratory gurgling or rattling in the throat of a dying person, caused by the loss of the cough reflex and the accumulation of mucous.

The embalming process is intended to what?

Retard, interrupt, or reverse the changes.

Taphonomy

Scientific study of decomposition.

Autolysis

Self-decomposition. The products of autolysis are - amino acids, sugars, fatty acids, and glycerol. In human remains the enzymes of decomposition have two different sources: saprophytic bacteria and lysosomes. These bacteria are normal residents of the human digestive tract. After death, they translocate and increase in number by using dead organic matter for their nutrition. Aerobic bacteria may also enter the body through the respiratory tract. They deplete the tissues of oxygen, producing chemical conditions favorable for anaerobic organisms, most of which originate in the intestinal tract. As the pH changes from alkaline to acidic, the membranes surrounding the lysosomes rupture. As the cells own digestive enzymes are released, they digest surrounding cellular material.

Death Struggle

Semi-convulsive twitches that often occur before death.

Agonal Hypostasis

Settling of the blood into the dependent tissues of the body. Occurs as a result of the slowing of circulation just prior to death, which allows the force of gravity to overcome the force of circulation.

Desquamation

Skin slip. The layers of the skin weaken because the deeper skin layers are undergoing autolysis. Hydrolysis of collagen and elastin causes the superficial skin to be pulled away easily from the deeper skin layers. As decomposition progresses, accumulations of gases and liquids can separate layers of skin, forming blisters.

Cadaveric Spasm

Sudden involuntary movement or convulsion brought about by involuntary muscular contractions, may also be associated with rigor mortis.

Decomposition of Carbohydrates

The breakdown of carbohydrates does not have any significant effect on embalming.

Translocation

The movement of microorganisms from one area of the body to another. It occurs as organisms normally confined to a specific area of the body by natural body defenses are able to move as the body loses its ability to keep them in check. The movement may be the result of the organism: 1. Having natural motility 2. Entering the blood stream and circulating to other parts of the body 3. Gravitating to other parts of the body during hypostasis or shifts in tissue moisture.

When the body is embalmed while the muscles are flaccid, what will happen?

The proteins will react well with the preservative and tissue fixation will occur. If the body is embalmed while rigor is fully developed, the stiffness of the muscles will impeded distribution. The proteins of the muscles are tightly bound together so they are less reactive.

Clostridium perfringens

The tissue gas-producing anaerobic bacillus is responsible for true tissue gas. Its presence throughout the body after death can bring about immediate embalming and preservation problems.