Chapter 13: Thanatology

Mesenteric thrombosis

________ and embolism leading to infarction of the gut are not sudden, but may be rapid and remain undiagnosed.

Viability

________ of transplantable tissues and organs falls sharply after somatic death; a liver must be removed within 15 minutes, kidney within 45 minutes and heart within an hour.

chemical stimulus

It can be confirmed by absence of any response to an electrical, thermal or ________ in the tissues.

Intestinal gangrene

________ due to strangulated hernias and torsion due to peritoneal adhesions can be a fulminant and fatal condition.

Blacks Law Dictionary

The ________ defines death as ‘ the cessation of life.

Harvard Ad hoc Committee on Brain Death

published a report describing the following characteristics of a permanently non functioning brain, a condition it referred to as "irreversible coma," now known as brain death

No movements or breathing

all spontaneous muscular movement, spontaneous respiration are absent

No reflexes

fixed, dilated pupils; lack of eye movement even when hit or turned, or ice water is placed in the ear; lack of response to noxious stimuli; unelicitable tendon reflexes

Somatic Death

the irreversible cessation of functioning of the brain, heart and lungs, resulting in complete loss of sensibility and ability to move the body

Cessations of heart beating

by careful auscultation of precordium for the heart sounds by a stethoscope continuously, for 5 minutes, and then repeating it thrice, at an interval of 5 minutes

Cessation of breathing

by thorough auscultation of the chest for the breath sounds using a stethoscope

Cessation of brain activity

by the dilated fixed pupil and absence of pupillary and corneal reflexes

Brain stem Death

The cerebrum is intact, but cut off functionally

Apnoeic test

No respiratory movement occurs when the patient is disconnected from the ventilator for long enough to ensure that the CO2 concentration in the blood rises above the threshold for stimulating respiration

Whole Brain Dead

It comprises a combination of both cortical and brain stem death

Anoxic anoxia

This is mainly due to mechanical asphyxia leading to defective oxygenation in lungs

Anemic anoxia

This is mainly due to the reduced oxygen carrying capacity of blood

Histotoxic anoxia

This is mainly due to the depression of tissue oxidation

Stagnant anoxia

This is mainly due to the inefficient circulation of blood

Stage of dyspnoea

This is due to excess accumulation of carbon dioxide, which stimulates the respiratory center resulting in increased rate and amplitude of respiratory movements

Stage of convulsions

This is due to lack of oxygen and the victim will show labored respiration, clouding of consciousness, convulsions, sphincteric relaxation, etc

Mechanism of Death

it is the physiological or biochemical derangement produced by the cause of death, which is incompatible with life and results in death

Contributory cause

the pathological process involved in or complications, but not causing the terminal event, e.g

Feather test

no movement of a feather held in front of the nose

Magnuss test (Ligature test)

fingers fail to show congestion distal to a ligature applied at their base

Icards test

fluorescent dye on being injected at a given site in a dead body fails to produce any discoloration

Fingernail test

no blanching and filling of blood in the fingernail on application of pressure and release

Suspended animation

a condition, wherein the vital functions of the body are maintained at a low pitch reduced to a minimum for sometime, that they cannot be detected by routine methods of clinical examination

Tachenoire (Taches Noire De La sclerotica)

is an artifact of drying consisting of brownish discolouration of sclera in exposed parts, when eyelids are not closed at death and left open for 2 to 3 hours

Postmortem lividity

the purplish or reddish purple areas of discolouration of skin and organs after death due to accumulation of blood in dependent parts of the body and seen through the skin

Rigor Mortis

the postmortem stiffening/rigidity of the muscles in a dead body

Primary Flaccidity

Immediately after death, as the control from brain on each of the muscles is lost and every muscle of the body shows complete relaxation

Secondary Flaccidity

When the molecular death has occurred in each of the actin and myosin filaments, the muscular stiffness that had developed earlier in the previous stage will begin to disappear slowly and gradually, relaxing the body back to the original state

Cadaveric spasm

condition wherein stiffening occurs in certain groups of muscles, which were already in a state of contraction at the time of death

Gas stiffening

this is due to accumulation of putrefaction gasses in the tissues so as to cause a false rigidity resulting in stiff limbs

Autolysis

self destruction

Bacterial Action

Certain bacteria can produce proteolytic and other enzymes, mainly lecithinase which are capable of bringing lysis of tissues

Marbling of skin

This is a color change scene in the form of mosaic like pattern on the skin on certain parts of a cadaver where the veins converge

Putrefaction in Water

It is slower than on ground, because of lower ambient temperature, non-availability of air and protection from insect and small animal predators

Pseudoabrasion

The animal eaten parts of the body may be mistaken for antemortem injuries

Skeletonisation

the complete decomposition of the non-bony tissues of a corpse, leading to a bare skeleton

CSF chloride level

It is found to decrease and a concentration below 440 mg per cent indicates PMI to be less than 25 hours

Blood creatinine value

It is found to increase after death

Radioactive carbon (C-14)

formed in atmosphere by the action of cosmic radiation and enters in all living beings through various channels, it gradually diminish after death

Adipocere formation

a modified process of putrefaction, wherein the fatty tissues of the body change into a substance known as adipocere, by hydrolysis and hydrogenation

Maceration

is due to autolysis in an aseptic environment

Freezing

If a body is kept in deep freeze or amidst thick layers of ice, it can remain in good preservation for a long time

Taxidermy

this process can be adopted for preservation of the dead body, especially when it is to be taken from one place to another for burial or to avoid putrefaction before cremation or burial, which might take some time

Thanatology

It is a subject that deals with scientific study of death, types of death, the various events, or changes that occur in the cadaver after death and their medico-legal significance.

Harvard Ad hoc Committee on Brain Death

It published a report describing the following characteristics of a permanently non-functioning brain, a condition it referred to as “irreversible coma,” now known as brain death:

Unreceptively and unresponsitivity

The patient shows total unawareness to external stimuli and unresponsiveness to painful stimuli.

No movements or breathing

All spontaneous muscular movement, spontaneous respiration are absent.

No reflexes

Fixed, dilated pupils; lack of eye movement even when hit or turned, or ice water is placed in the ear; lack of response to noxious stimuli; unelicitable tendon reflexes.

Black’s Law Dictionary

It defines death as ‘the cessation of life.’

Chamber’s Twentieth Century Dictionary

It defines death as ‘the extinction of life’.

Death

_____ is a process not an event and, while the cells of some tissues are still alive and even capable of movement, others are dying or dead.

Somatic Death

the irreversible cessation of functioning of the brain, heart and lungs, resulting in complete loss of sensibility and ability to move the body.

Cessations of heart beating

by careful auscultation of precordium for the heart sounds by a stethoscope continuously, for 5 minutes, and then repeating it thrice, at an interval of 5 minutes. A flat ECG may also confirm it.

Cessation of breathing

by thorough auscultation of the chest for the breath sounds using a stethoscope.

Cessation of brain activity

by the dilated fixed pupil and absence of pupillary and corneal reflexes. A flat Electroencephalogram (EEG) would confirm it.

Molecular Death

The ultimate death of all cellular elements.

Cerebral/Cortical Death

The brain stem is intact, with continuous heart sounds and respiration, but total loss of sentient activity.

Brain Stem Death

The cerebrum is intact, but cut off functionally.

Apnoeic test

No respiratory movement occurs when the patient is disconnected from the ventilator for long enough to ensure that the CO2 concentration in the blood rises above the threshold for stimulating respiration.

Time of Death

The time at which brain stem death is established. This does not coincide with the time when the ventilator is switched off; or heartbeat ceases.

Whole Brain Dead

It comprises a combination of both cortical and brain stem death. Clinical definition of death has been now modified as irreversible state of coma consisting of:

Syncope

a result of sudden stoppage of functioning of the heart, which may prove fatal.

Asphyxia

a condition resulting from interference with respiration or sudden stoppage of functioning of the lung causing unconsciousness or death.

Gordon’s Hypothesis

emphasizes the fact that tissue anoxia, irrespective of its origin can invariably lead to the cessation of vital functions, especially circulatory failure resulting in death.

Anoxic anoxia

This is mainly due to mechanical asphyxia leading to defective oxygenation in lungs.

Anemic anoxia

This is mainly due to the reduced oxygen carrying capacity of blood.

Histotoxic anoxia

This is mainly due to the depression of tissue oxidation.

Stagnant anoxia

This is mainly due to the inefficient circulation of blood.

Stage of dyspnea

This is due to excess accumulation of carbon dioxide, which stimulates the respiratory center resulting in increased rate and amplitude of respiratory movements.

Stage of convulsions

This is due to lack of oxygen and the victim will show labored respiration, clouding of consciousness, convulsions, sphincteric relaxation, etc.

Stage of exhaustion and respiratory failure

It lasts for 2 to 3 minutes. Respiratory and other nervous centers are completely paralyzed.

Coma

* Results from sudden stoppage of functioning of the brain.
* It is a state of unarousable unconsciousness determined by absence of any psychologically understandable response to external stimuli or inner need.
* It is due to paralysis or insensibility of central portion or vital centers of the brainstem.

Manner of death

explains how the cause of death came about. It is generally considered to be natural, homicide, suicide, accident, and undetermined.

undetermined

Manner of death is ______, when the facts are insufficient about circumstances surrounding the death, or when the cause of death is unknown.

unclassified

Suicide, accident, homicide, natural and undetermined, some people use the term ______. This also refers to death in which the cause and circumstances are not known.

Agonal Period

It is the time between a lethal occurrence and death.

Mechanism of Death

it is the physiological or biochemical derangement produced by the cause of death, which is incompatible with life and results in death.

Cause of Death

the disease or injury that produces a physiological derangement in the body that results in death of the individual.

Immediate cause

the actual cause at the time of terminal event, e.g. bronchopneumonia, peritonitis, trauma, etc.

Antecedent cause

the actual pathological process responsible for the death at the time of the terminal event or prior to or leading to the event, e.g. gunshot wound of abdomen complicated by generalized peritonitis.

Contributory cause

the pathological process involved in or complications, but not causing the terminal event, e.g. Carcinoma stomach.

Cardiac tamponade

constitutes a lesion wherein ruptured myocardial infarct, trauma, etc. results in collection of blood in the pericardial sac.

Insensibility

comprise complete loss of response to sensation.

Feather test

A test where no movement of a feather held in front of the nose.

Mirror test

A test where mirror held in front of the nose does not turn dim due to any moisture of breath.

Winslow’s test

A test where no movement of surface of water in bowl kept on the chest.

Circulatory Arrest

It is the complete absence of heart sounds for more than 3 to 5 minutes.

Respiratory Arrest

It is the complete stoppage of respiration for more than 3 minutes.

Magnus’s test (Ligature test)

A test where fingers fail to show congestion distal to a ligature applied at their base.

Diaphanous test (Transillumination test)

Failure to show redness in the web space between the fingers on transillumination from behind.

Icard’s test

A test where fluorescent dye on being injected at a given site in a dead body fails to produce any discoloration.

Fingernail test

A test where no blanching and filling of blood in the fingernail on application of pressure and release.

Suspended animation

a condition, wherein the vital functions of the body are maintained at a low pitch reduced to a minimum for some time, that they cannot be detected by routine methods of clinical examination.

Voluntary Suspended Animation

happens from yoga practice.

Involuntary Suspended Animation

happens in newborn infants, insanity, drowning, electrocution, cholera, frozen coma, after anesthesia, typhoid state, shock, sun-stroke, etc.