Morphologic Appearance of Postmortem Changes Flashcards
(32 cards)
Occurs After Somatic Death
Autolyisis
Due to total Diffuse Hypoxia.
Somatic Death
Process by which post mortem bacteria break down tissues [gives color, texture changes, gas production odors]
Putrefaction/Decomposition
Which tissues will undergo autolysis first?
Tissues with greater concentration of proteolytic enzymes
- gastrointestinal tract
- pancreas
- gall bladder
- Liver
- Kidneys
Morpholgic appearance of postmortem changes vary depending on:
Cause of death
Environmental and body temperature
Microbial Flora
- Defined as mild, moderate, to severe
What inhibits autolysis, delaying putrefaction?
Cool Environmental Temperatures and refrigeration
- Not recommended to freeze the carcass
Exceptions to inhibition of autolysis by refrigetartion include:
BECAUSE:
Ruminants forestomach
Equine Cecum and Ascending Colon
- ingesta will continue to undergo bacterial fermentation after death►gas and heat
Refers to the contraction of the muscles after death
Rigor Mortis
When does Rigor mortis occur?
Begins at 1-6 hours post death, is persistent 1-2 days
What factors can accelerate the onset of rigor mortis?
High heat and high activity before death accelerate the onset of rigor mortis
Cooling of the body post mortem
Algor Mortis
What factor influences algor mortis?
Depends on the temperature of the body at time of death
This is caused by gravity pulling blood post death.
Causes a variation in color of skin, lung, heart, kidneys, liver
Some areas he tissue will be more red and in other areas pale due to that the blood was kept away
Only a post mortem change [no blood pressure]
Livor mortis:
AKA Hypostatic Congestion
When and where does post mortem clotting occur?
Several hours post death in the heart and vessels
What is post mortem clotting influenced by?
Ante mortem changes in the blood
i.e. warfarin poison, hereditary coagulopathies can delay or cause failure of blood to clot
Due to seperation of RBCs to the bottom and clotted serum at top
Chicken clot appearance
Pre-Mortem Clotting characteristics:
Atached to vessel walls (arterial type)
Loosely attached to vessel walls (venous thrombi, may resemble post mortem clots)
Dry, duller color, laminated
Post mortem clot characteristics:
Unattached to vessel walls
Shiny and wet, perfect cast of vessel lumina
Red staining of tissue, especially the heart, arteries and veins
Hemoglobin imbibition
What causes Hemoglobin imbibition?
- hemoglobin is released by lysed RBCs and penetrates the vessel wall and extends into the adjacent tissues
Tissue sensitivity to hypoxia is dependant upon:
Energy demands of the cell and/or its ability to utilize anaerobic glycolysis as a source of energy
Neurons>Hepatocytes,Myocardium, Renal Epithelium>Fibroblast, Epidemia, Skeletal Muscle
True or False:
Hemoglobin staining can occur in acute intravascular hemolysis
TRUE
Identify
Bile Imbibition
How does bile imbibition occcur?
Bile in the gallbladder starts to penetrate the wall and stains the adjacent tissue yellowish to greenish brown
