Path Summer 1

What types of damage to bone occur as a result of canines?

"V" shaped injury Punctures Pits Scoring Furrows

Tardieu spots

A type of lividity that occurs when the PMI increases (18-24hrs) and BVs rupture as a result of the pressure from the blood accumulating in lividity

What other bacteria are responsible for Putrefaction in the colon/bowel?

Aerobes (enterococci, proteus) 1-4% of bacteria in colon/bowel

Why does fixed LM occur?

After being in one position for long enough, the fat surrounds and closes off the capillaries of blood vessels so that the blood can't escape

When do beetles typically begin to colonize bodies?

After flies and maggots since they like to feed on fly eggs and larvae

Three basic things we can look at to help determine time of death

Algor Mortis Livor Mortis Rigor Mortis

Medical Examiner

Appointed position, almost always a physician and usually a board certified forensic pathologist

Where does one of the earliest signs of decomposition occur?

Around the appendix

Coroner

Elected position (you only need to be 18y/o, a registered voter, and have a high school diploma)

Are Tardieu spots larger or smaller than petechiae?

Larger! And they're only found in areas of lividity

What finding might be confused w/ drag marks?

Linear marks from 3instar maggots crawling away to pupate

What pm change may falsely lead you to think that the patient had pneumonia?

Livor Mortis in the lungs! It can mimic pneumonia

Adipocere formation

Malodorous, cheesy compound that results when a body is placed in a moist environment

Accident death

Manner of death caused by violent means not due to intentional or criminal act by another person

Natural death

Manner of death caused exclusively by disease (MI, stroke, sepsis, etc.)

Undetermined death

Manner of death which, after a complete autopsy/investigation of circumstances, doesn't have a determined cause

Homicide death

Manner of violent death at the hand of another person due to a hostile or illegal act of that person (i.e. gunshot wound)

Suicide death

Manner of violent death caused by an act of the decedent w/ the intent to kill himself

Which gas mostly causes distention of the abdomen and scrotum?

Methane

What are the products of decomposition produced by bacteria?

Methane (bloating) Hydrogen Hydrogen sulfide Carbon dioxide Alcohol Ammonia (amino acids break down --> release nitrogen, form ammonia)

Viracow method of autopsy

Method of autopsy that looks internally and then takes organs out separately

Rokitansky method of autopsy

Method of autopsy that takes all of the organs (from the tongue to the rectum) out in one big block

Will someone who is very muscular have more significant or less significant Rigor?

More significant

What type of decomposition tends to be seen in dry areas, extremes of hot and cold, and indoor deaths?

Mummification

What color is urobilin?

brown

Livor Mortis

Purple/red discoloration in the dependent areas of the body due to accumulation of blood after cardiac activity has ceased

What form of decomposition results in the gut as bacteria proliferate unchecked?

Putrefaction

What are the products of Putrefaction?

Putrescine Cadaverine Biliverdin Bilirubin Urobilin Hydrogen Sulfide

What is the difference b/w a rat indentation and a canine indentation?

Rats produce parallel striae with their incisors rather than V-shaped indentations

What color is bilirubin?

Red

Why does pm ejaculation occur?

Rigor Mortis occurs in the muscles of the seminal vesicles

What is "gooseflesh?"

Rigor mortis in the erector pillae muscles of the skin/hair follicles

Typically, beetles like to feed on remains in what location?

Sheltered, dried, and mummified**

What changes occur during advanced decomposition?

Significant color changes, bloating, and some tissue loss

Which types of beetles feed on decomposing flesh?

Silphids and dermestids

What changes occur during early decomposition?

Skin slippage and color changes

Rigor Mortis

Stiffening of the muscles after death due to lack of ATP

Where to cockroaches tend to feed?

Superficial keratinized portions of the epidermis

True or False: Rigor Mortis involves all muscles at the same time and at the same rate

TRUE

True or False: Rigor resolves more quickly in a warm environment

TRUE

True or False: larval masses can move remains

TRUE

True or False: lividity becomes darker the longer that a person is dead

TRUE

What changes occur during fresh decomposition?

The body has just died, may have some rigor or algor mortis

What does it mean if rm is inconsistent w/ gravitational forces?

The body was moved!

Cadaveric spasm

The instantaneous type of rigor mortis

What might happen to solid organs during decomposition?

They tend to get spongy from gasses expanding and creating bubbles

What is "unfixed" LM?

When you press on the LM and it blanches

What is "fixed" LM?

When you press on the LM and it doesn't blanch

What color will plant matter be if it is growing towards a body?

Yellow tinged "chlorosis" from the body's amino acids

Which parts of the body will canines tend to feed on first?

face, neck, hands then, thorax, upper extremities, clavicles as the body decomposes- makes it easier to disarticulate long bones, etc.

Skeletal remains degrade more quickly in a wet environment or an ____/_____ environment

acid/alkaline

What color is hydrogen sulfide?

black

What produces cadaverine?

breakdown of amino acids

What produces putrescine?

breakdown of amino acids

In what order to the tissues tend to decompose?

intestines/heart/stomach/blood/digestive organs air passages and lungs kidneys and bladders brain and nervous issue skeletal muscle connective tissue

If beetles are feeding, how long is the PMI?

months to years

Autolysis begins sooner in which organs?

those w/ abundant lysosomes

What happens to the vitrous potassium as the time since death increases?

vitrous potassium increases as well (not in a predictable way, though)!! (vs. vitreous glucose, which decreases)

What groups of people may have minimal lividity?

1) Anemic 2) Those who were stabbed/shot and became hypovolemic They both have dec. circulating volume

What does cherry red lividity indicate?

1) Carbon monoxide poisoning 2) Cyanide poisoning 3) Cold temperatures

How long does it take a body to skeletonize if buried at a depth of 4+ feet?

2-3yrs

When does Rigor Mortis usually begin?

2-4hrs after death OR if they're using a lot of ATP at the time of death, it can begin much more quickly

When does Livor Mortis begin?

30min-2hrs after death

When does Rigor Mortis typically resolve?

36hrs

What stage of development does a fly/maggot need to be in in order to determine the species?

3rd instar

What is a lethal CO2 level?

40%

How long does it take a body to skeletonize if buried at a depth of one foot?

6mo

When does Livor Mortis usually become fixed?

8-12hrs after death

Forensic pathology

A branch of medicine that applies the principles and knowledge of the medical sciences to problems in the field of law

What is biliverdin and what color is it?

A breakdown product of blood- has a green color to it

Algor Mortis

A decrease in body temperature after death

What is a peritrophic membrane?

A protective covering of beetle fecal matter, also known as beetle frass

How long does it take a fly to go from an egg to a mature, adult fly?

About 2wks

What is Rigor Mortis determined by?

Ambient temperature and metabolic state at the time of death

What kind of bacteria in the colon/bowel are most responsible for Putrefaction?

Anerobes (bacteroids, clostridia) Account for 96-99% of bacteria in the colon/bowel

What must purge fluid be differentiated from?

Antemortum trauma (since it can be blood tinged)

Cause of death

Any injury or disease that produces a physiological derangement in the body that results in the individual dying (cancer, pneumonia, etc.)

What are the four breakdown products of hemoglobin?

Biliverdin Bilirubin Urobilin Hydrogen Sulfide

What type of decomposition is typically seen in cities and moist areas?

Bloating

What is a secondary grave depression?

Bloating causes movement of soil, followed by collapse back down when bloating resolves

What areas of the body will begin to decompose first?

Blood rich areas (lividity)

Forensic anthropology

Branch of pathology that deals predominantly w/ skeletal remains (determining height, etc.)

Forensic odontology

Branch of pathology that deals w/ dentistry, can identify remains using teeth, examine bite wounds, etc.

Forensic ballistics

Branch of pathology that deals with bullets and firearms

Forensic botany

Branch of pathology that examines the plant activity growing around the body, can help you determine how long body has been there

Forensic toxicology

Branch of pathology that looks into ETOH use, drugs of abuse, etc.

Forensic entomology

Branch of pathology that studies bugs (insects that colonize your body when you die, etc.)

How is scoring typically produced?

By the molars of the dogs, producing grooves in the bone

Vitreous humor glucose level

Can be used during an autopsy toxicological analysis to see how long the person has been dead (glucose decreases as PMI lengthens)

Besides tache noir, what are the other two post-mortem eye changes that take place?

Clouding of the cornea early on Sludging and intravascular coagulation of retinal vasculature

What species can cause superficial feeding artifacts of the skin that look like thermal burns?

Cockroaches

What species may feed on the eyebrows b/c of their big mouths?

Cockroaches/dictyopetera

What is another name for cockroaches?

Dictyoptera

Tache Noir

Dark band of dried epithelium on the sclera when the eyes don't close completely

Why does bullae formation occur?

De-compositional fluid expands between the dermis and the epidermis

Putrefaction

Decay/rotting produced by bacteria that contributes to decomposition

What is purge fluid?

Decomposed gastric lining and contents that expand up and out of the nose and mouth

What do Tardieu spots indicate?

Decomposition that is rapidly approaching

Does clean water increase or decrease decomposition?

Decrease

Does salt water increase or decrease decomposition?

Decreases b/c it acts as a bactericidal

What changes can plant material make to a body?

Degrade clothing Degrade tissue Cause grooving of the outer bone cortex

What beetles produce peritrophic membranes?

Dermestid beetles

True or false: temperature decreases at a readily detectible level in Algor Mortis

FALSE

True or False: maggots/larvae can create bore holes through bone

FALSE- only tissue

Where might drugs be deposited in the exoskeleton of an insect that was feeding off of a dead body?

Fat bodies and chitin of the exoskeleton

Where does adipocere formation typically occur in the body?

Fatty portions like the brain

What are the four stages of decomposition?

Fresh Early Advanced Skeletonization

Where does tissue decompensation occur first?

G tract b/c that's where the bacteria are

What is adipocere formation also known as?

Grave wax

At what rate will a submerged body decomposed compared to a body that decomposes in air?

Half of the decomposition rate of air

What causes adipocere formation?

Hydrolysis and hydrogenation of fats to fatty acids

What is another name for wasps?

Hymenoptera

Where is Rigor Mortis most evident?

In smaller muscle groups!! It gradually becomes more evident in larger muscle groups

What is marbling?

Intravascular hemolysis (as blood vessels decompose, they give the body a marble pattern like a statue, table, etc.)

Should a body with no maggots skew your idea of the PMI?

No, because ants and wasps may have eaten the maggots

Where do female flies usually lay their eggs?

On a food source in a moist environment (eyes, mouth, nose) with protection from solar radiation

In what environments will a body decompose most rapidly?

On the surface of the ground most rapidly, then when the body is in water, and then when the body is buried

What is a primary grave depression?

Outline of the grave from settling of soil

How can you break Rigor Mortis?

Passive stretching of the muscles

External autopsy examination

Portion of autopsy that looks for things like pitting edema, skin lesions, etc.

Internal autopsy examination

Portion of autopsy that uses either the Rokitansky or Viracow method to examine the organs

Why is LM typically red-purple?

The oxygen is dissociating from hemoglobin, and deoxyhemoglobin is typically purple

Pedestal phenomenon

When rodents chew away the epiphyseal cartilage (the softest part), leaving adjacent areas of long bone on a 'pedestal' since the epiphysis and metaphysics are still attached

What two other arthropods colonize the body and like to feed on fly eggs and larvae?

Wasps and ants

What determines when a submerged body will resurface?

Water temperature

What is autolysis?

hydrolytic enzymes released by lysosomes, triggered by a decrease in cellular pH

What is skin slippage?

release of hydrolytic enzymes at the dermal/epidermal junction, allowing the epidermis to slough off of the dermis like a glove/sock