1.2.1 Autopsy Test Review

How do different surrounding air temperatures affect the body's rate of cooling?

- body temp decreases at a slower rate in warmer surroundings while body temperature decreases at a faster rate in cooler surroundings - a body in an environment with a colder ambient temp than body temp will decrease more quickly in temp until it matches the ambient temp - a body in an environment with a warmer ambient temp than body temp will increase less quickly in temp until it matches the ambient temp

Medical examiner: Day to day tasks Challenges of the job

- perform autopsies, complete follow-ups, dictations, and reports on cases and testify in court - staying strong when working on tough cases, being sympathetic in horrible situations with sad families, and maintaining a full staff due to the nationwide shortage of forensic pathologists

Define decomposition When it begins/ends How it's used

- the body turns greenish in color and may sweep or bloat as bacteria break down tissue and release gas; also comes with a nasty smell - it begins 36-48 hours after death - the stage of decomposition of the body can help estimate the time of death

Define Algor mortis When it begins/ends How it's used

- the change in body temperature after death - it begins immediately after death and ends within 24 hours of death - it's estimated that a body loses or gains 1.5 degrees per hour so this can help estimate the time of death but external factors make it challenging to pinpoint an exact time of death

Define insect activity When it begins/ends How it's used

- the presence of eggs, larva, or full-grown bugs appear on the body as the body decays - it occurs between 1-145 hours - it can provide clues about how long a person has been death because the presence of certain insects or eggs can provide a timestamp for how long the body has been decaying

Define liver mortis or lividity When it begins/ends How it's used

- when the heart stops beating, the blood is at the mercy of gravity so blood settles or collects on the parts of the body facing the ground - early signs occur within the first 2 hours of death while full signs occur within 5 hours; lividity is fixed in place within 8-12 hours - the severity of liver mortis shown can help estimate the time of death

How long does primary flaccidity last after death?

1 to 2 hours

Timeline after death: 30 mins

Blood continues to collect(liver mortis). The body temperature continues to change(algor mortis).

Timeline after death: 36 hours

Decomposition begins. There is insect activity.

Mechanism of death examples:

Exsanguination(blood loss), cardiac arrhythmia(irregular heart rhythm), air embolism(blockage in blood vessel), sepsis leading to organ failure

Manner of death examples:

Homicide, accident, natural

Cause of death

It is the injury, trauma, or disease that directly caused the victim to die

Manner of death

It is the situation that results in death end is either natural or unnatural

Mechanism of death

It is what happens inside the body that results in death

What are the categories of manners of death?

Natural, accident, homicide, suicide, or undetermined

Paragraph relating the cause, mechanism, and manner of featg

People die from a cause of death. The cause of death triggers the mechanism of death. The manner of death is what categories and helps explain the cause of death.

Timeline after death: 24 hours

The body reaches the temperature of the surrounding environment(algor mortis). There is insect activity.

Timeline after death: Immediately

The body starts changing temperature to reach the temperature of the surrounding environment(algor mortis). Blood begins to settle on the parts of the body facing the ground(liver mortis).

A body is found lying face down, with fixed lividity on their back. What does this tell investigators?

The body was moved after death

Explain the importance of a control group in an experiment

The control group affects your conclusion, as it is what you compare your results to. It is used as a benchmark to measure change in the experiment

Timeline after death: 2-4 hours

The corneas begin to cloud and the muscles start to contract and stiffen(rigor mortis). Early signs of blood settling are present and full signs start to show(liver mortis). The body continues to change temperature(algor mortis). There is insect activity.

Physiological Time of Death

Time at which the decedent's vital functions actually stopped

Estimated time of death

Time at which the medical examiner estimates that the death occurred

Legal time of death

Time of death that is recorded on the death certificate; it is based on when the body was found or physically pronounced dead

A body is found in "Peak rigor," approximately what is the PMI, or tie since death?

approximately 12 hours ago

How to convert from Celsius to Fahrenheit

(°C x 1.8) + 32 = °F

Morgue Autopsy

- Where a dead body is stored - conducted by medical examiners; all bodies are labeled that come from a morgue

What is a body farm? Where is the first one? Why are they made?

- a body farm is a research compound where scientists study what happens to human bodies after death - the first body farm was founded at the University of Tennessee in Knoxville - the observations and data collected at body farms contribute to forensic scientists' understanding of the factors that impact how a body changes after death

Define rigor mortis When it begins/ends How it's used

- after the body stops functioning, the muscles contract and stiffen - it begins 2-4 hours after death and full rigor is present throughout the body in 8-12 hours; after 36-48 hours, rigor fades as decomposition begins - the severity or spreading of rigor mortis shown can help estimate the time of death

A body is found to have flaccidity in the upper body but rigor in the lower body. Approximately what is the time since death?

approximately 18 hours - the body has already peaked (over 12 hours) and is now losing its rigor. Rigor is lost in the small muscles like the eyelids/fingers first, and then slowly is lost in the legs and feet

Why is pallor mortis not typically used to determine PMI

because it is unprobable for a medical examiner to arrive at the scene within 30 minutes of death

Rigor mortis is lost

in the same order that they began contraction

Which indicator is most reliable in determining PMI?

rigor mortis; this process occurs progressively throughout the body

Rigor mortis will begin around 2 hours after death in which parts of the body?

small muscles such as the eyelids and neck

If the outside temperature is higher than 37 degrees Celsius, the body temperature will

still decrease, just at a much slower rate

"PMI" or "Post Mortem Interval" can also be referred to as

the time since death

How does heat travel from the inner organs to the outer organs during algor mortis?

through blood

Steps of an autopsy: Brian exam Tools External exam identification Documentation Internal exam Sample collection Stomach contents Gross examination

- brain is checked for signs of injury and is removed from the skull, it is then weighed and examined - various saws, needles, and scissors are needed to complete the internal examination as well as stitch up the body after the autopsy is finished - description of the body is recorded, it is measured and weighed, evidence of external unhurt is also noted - features of identity are noted, ID by personal documents are also noted - photographs are taken to document injury, features of identification, and/or the state of decomposition - the first cut extends from each shoulder to the center of the chest and down the center of the body ("Y incision"), then organs are examined in place and then removed to be examined and weighed - samples of blood, urine, and tissues are collected and sent away for additional testing to help determine identity and/or cause of death - the stomach contents are examined and the identity and degree of digestion of foods is determined which may help determine the time of death - gross examination refers to the study of anatomy at the visible or macroscopic level rather than the microscopic level

Define clouding or corneas When it begins/ends How it's used

- clear parts of the eyes become milky or cloudy - within the first several hours after death - the degree of cloudiness can help estimate when the person died

Autopsy report: Lab results

- describe additional blood or urine testing results (outside of the toxicology screens)

Autopsy report: Evidence of injury

- describe any wounds, cuts, bone breaks, or other invasive injury, including locations and measurements

Autopsy report: Features of identification

- describe how an ID was made and confirmed - could be made through ID by a family member but usually happens through photos, scars, marks, tattoos, ID carried like a drivers license - further ID may include fingerprints, dental records, surgical records, medical device records, and DNA

Autopsy report: Histology results

- describe the analysis of tissue samples that were taken from the main organs of the body and may highlight traumatic injury, evidence of cancer, damage due to a natural disease process, or events such as a heart attack

Autopsy report: Toxicology results

- describe the rest it's of routine toxicology testing typically completed for all autopsies (includes a drug screening)

Autopsy report: Postmortem changes

- detail evidence that may be linked to determination of time of death (rigor mortis, ocular clarity, etc.)

Autopsy report: Internal examination

- document abnormalities or injury to internal organs as well as the presence of normal structures - this surgical procedure includes an examination of the organs in the body and the removal of these organs for examination and weighing - tissue samples of each organ are typically collected and sent away for histological testing

Autopsy report: Anterior and Posterior

- document the location of injuries noted on the report; photographs are also taken

Autopsy report: External examination

- document the overall condition of the outside of the body (as determined visually and by palpation) - include info on scars, marks, and tattoos - this section will not typically include injury and trauma (recorded in a different section)

Autopsy report: Forensic autopsy Clinical or pathological autopsy

- if they seek to find the cause and manner of death or to ID the decadent - to diagnose a disease or for research

Autopsy report: Front analysis Top analysis Side analysis

- illustrate damage to the skull (if any)

Autopsy report: Cause of death

- list a cause, mechanism, and manner of death

Autopsy report: Clothing/personal effects

- list of any items that are found on the body before the autopsy procedure begins (includes clothing, jewelry, wallets, or other personal items

Autopsy report: Case summary

- opinion of the medical examiner - provide a narrative about the overall findings and details of the case

At approximately what time does rigor mortis "peak"? (This means approximately all of the muscles in the body are stiff)

12 hours

Timeline after death: 8-10 hours

Full rigor is present in the body(rigor mortis). Lividity is fixed in place(liver mortis). The body continues to change temperature(algor mortis). There is insect activity.

Cause of death examples:

Gunshot wound, drug overdose, stab wound, bacterial infection

Timeline after death: 36-48 hours

Rigor fades(rigor mortis). Decomposition continues. There is insect activity.

After death, the body temperature

decreases

We can only approximate how quickly body temperature falls because

many factors play a role in how the body temperature decreases