PRELIM LEC: SOMATIC DEATH Flashcards
Refers to the complete cessation of metabolic and functional abilities of an organism
SOMATIC DEATH
Occurs 4-6 minutes, then death follows
Primary Changes of Death
Primary Changes of Death (CRC)
- Circulatory failure
- Respiratory failure
- Central Nervous System failure
start of death when cardiac function
ceases; flat electrocardiogram (ECG), and/or absence of heartbeat is indicative
Circulatory failure
decrease O2 and increase CO2; loss of all
processes necessary for life; absence of respiratory sounds and movements is indicative
Respiratory failure
loss of coordination and reflexes; absence of brain stem reflex, and/or electroencephalogram (EEG) activity is indicative
Central Nervous System failure
Secondary Changes of Death (ARLPDPA)
- Algor Mortis
- Rigor Mortis
- Livor Mortis/Sugillation
- Post-mortem Clotting
The next 3 stages of death occurs simultaneously and leads to the total digestion of cells:
5. Dessication
6. Putrefaction
7. Autolysis
Cooling of the body; decrease in temperature
Algor Mortis
Equalizing of the body temperature to the external temp
Algor Mortis
Algor Mortis Normal rate of cooling:
7 Fahrenheit/hr
Algor Mortis Sped up by:
cold environment, malnutrition/dehydration, severe hemorrhage
Algor Mortis Slowed by:
fever, extreme physical activity before death
Stiffening of muscles due to lack of ATP (ATP is
responsible for driving calcium ions back to sarcoplasmic reticulum of muscles)
Rigor Mortis
First appears in the involuntary muscles of heart
Rigor Mortis
Observed in eyelids, followed by neck, then lower extremities
Rigor Mortis
Starts 2-3 hrs post-mortem, completes 6-12 hrs post-mortem; persists for 3-4 days
Rigor Mortis
After 3 to 4 days, relaxation occurs due to breakdown of contracted muscles
Rigor Mortis
Rigor Mortis Factors:
muscle activity by the time of death;
Rigor Mortis Sped up by:
warm environment; infancy; thin-layered muscles
Rigor Mortis Slowed by:
cold environment; obese people
Purplish discoloration of skin due to blood stasis
Livor Mortis/Sugillation
Blood vessels dilate due to loss of muscle tone
Livor Mortis/Sugillation
Lividity of the dependent portions of the body due to settling of blood to the lowest parts of the body at the time of death
Livor Mortis/Sugillation
Cause
Livor Mortis/Sugillation
Post-mortem stasis of blood
After application of pressure (Blanching test)
Livor Mortis/Sugillation
Discoloration disappears
After incision
Livor Mortis/Sugillation
Has oozing
Cause
Ecchymosis
Trauma
After application of pressure (Blanching test)
Ecchymosis
No disappearance
After incision
Ecchymosis
No oozing
Occurs immediately after death; apparent only in autopsy
Post-mortem Clotting
Appearance
Post-mortem Clotting
Upper layer is clear (resembles chicken
fat); RBC settles at the lowest part of the blood vessel (resembles currant jelly)
Consistency
Post-mortem Clotting
Rubbery
Shape
Post-mortem Clotting
Assumes blood vessel shape
Appearance
Ante-Mortem Clot
Has tangled, irregular fibrin
Shape
Ante-Mortem Clot
Seldom assumes blood vessel shape
Consistency
Ante-Mortem Clot
Non-rubbery
General drying and wrinkling of fluid-filled organs;
Dessication
most evident in the cornea, and anterior chamber of eye
Dessication
Decomposition of body carried out by microbial action (normal flora from gut migrates to blood vessels and spreads all over the body)
Putrefaction
Putrefaction Principal agent:
Clostridium welchii (gram-positive,
anaerobic, rod-shaped)
Putrefaction First external sign:
Greenish discoloration of skin over the
right iliac fossa due to bacterial hydrogen sulfide reacting with hemoglobin, thus forming sulphahemoglobin which stains the area green
Eventual production of foul-smelling gas due to invasion of saprophytes, which leads to distension of abdomen, swelling of face and genitalia, and liquefaction of internal organs
Putrefaction
Most resistant to putrefaction: prostate gland
Putrefaction
“Self-destruction”; the self-digestion of the cells by their own enzymes;
Autolysis
First external sign is the whitish appearance of cornea
Autolysis
The next 3 stages of death occurs simultaneously and leads to the total digestion of cells:
- Dessication
- Putrefaction
- Autolysis
