Unit 3 Test PLTW

Morgue

Where an autopsy occurs

Autopsy

-Systematic examination of the entire body

-Completed postmortem or after death

Reasons for Autopsy

-When a death is unexpected or suspicious

-When there is a public health concern

-Upon request

Autopsy Professionals

-Medical examiner

-Coroner

What do autopsies study?

-Changes to the external or internal structures of the body

-Body tissues and fluid

-Places with clues about diseases

-Evidence of chemicals and toxins

Manners of Death

-Natural

-Accidental

-Homicide

-Suicide

-Undetermined

Natural Death

-Interruption and failure of body functions resulting from age and disease

-ex. heart failure, cancer

Accidental Death

-Caused by unplanned events

-ex. car accidents, falling from a ladder

Suicide

-Person purposefully killing oneself

-ex. hanging, drug overdose, gunshot

Homicide

-Death of one person caused by another person

-ex. murder

Undetermined Death

-Listed as the official cause when cause cannot be determined

Cause of Death

-What caused the death to occur

-ex. disease, injury, stroke, heart attack, shooting, drowning, strangulation

Mechanism of Death

-Specific change that brought about death

-ex. loss of blood, pulmonary arrest

Autopsy Report

-Completed data observations and findings recorded in a detailed paper

Physiological time of death

-Vital functions actually ceased

Estimated time of death

-Medical examiner estimates that the death occurred

Legal time of death

-Time of death recorded on the death certificate

-Based on when the body was found or physically pronounced dead

Livor Mortis

-RBC break down and a blue-purple color forms

-Blood seeps down and settles in lower parts of the body

What is Livor Mortis also known as?

-The Leaden-Color of Death

Livor Mortis Time Frames

-Begins 2 hrs after death

-Becomes permanent after 8 hrs

-Accelerates with warmth

Rigor Mortis

-When skeletal muscles do not relax at death

-Calcium accumulates in the muscles and makes them stiff

-Starts in the head and works its way down

What is Rigor Mortis also known as?

-The rigidity of death

Rigor Mortis Time Frame

-Muscle fibers begin to dissolve after 15 hrs

-Body is at its most rigid state at 12 hrs

-If the body has no visible signs of rigor, it has been dead for less than 2 hrs or more than 48 hrs

-If it is only visible in the next that means it has been just over 2 hrs

-Most stiffness will disappear after 36 hrs

Algor Mortis

-The body no longer generates warmth and begins to cool down

-Body heat is lost at about 1 to 1.5 degrees an hour

-A thermometer is inserted into the liver to calculate temperature

What is Algor Mortis also known as?

-The chill of death

Changes to the eye after death

-Surface of the eye dries out

-Thin film will show within 2-3 hours if eyes are open

-Thin film will show within 24 hours if eyes are closed

-Potassium accumulated inside the vitreous humor

Glaister Equation

-Can calculate time of death

-(98.4°F - Measured Body Temp) / Rate = Hours

Decomposition in 2 days

-Cell autolysis

-Green and purplish staining from blood decomposition

-Skin looks marbled

-Face becomes discolored

Decomposition in 4 days

-Skin blisters

-Abdomen swells

Decomposition in 6-10 days

-Corpse bloats

-Fluids leak from body openings

-Eyeballs and other tissue liquify

-Skin sloughs off

Forensic Entomologist

-Study arachnids, such as mites, spiders, ticks, and insects, such as flies

Flies (Forensic Entomology)

-Blowflies are found at sites of decay

Scene Markers

Clues left at the scene that help establish a timeline

-Ex. texts, emails, clocks, etc.

Toxicology

-Field of science that studies the effects of chemicals, such as drugs, alcohol, poisons, metals, and gases on the human body

Safe Dosage

Depends on factors such as height and weight

Reactions to medications and chemicals

Depend on what other substances are in a person's system

Exposure to Toxins

-Acute: short term

-Chronic: long term

Samples to Test

-Urine

-Blood

-Saliva

-Hair

-Breath

Digestive System Parts

-Mouth

-Esophagus

-Stomach

-Liver

-Small Intestine

-Large Intestine

Forensic Chemists

-Test non biological samples such as powders, pills, and other substances to determine their identity, components, or concentration

Presumptive Test (Forensic Chemistry)

-Quick tests that indicate if a type of substance is present

-Ex. Marquis test for opioid-based drugs

Confirmatory Test (Forensic Chemistry)

-Tests that can determine the exact identity and composition of a substance

-Ex. Gas Chromatography

Right side of the heart

-Pulmonary Pump

-Pumps deoxygenated blood to the lungs to get oxygen

Left side of the heart

-Systemic Pump

-Pumps deoxygenated blood to the whole body

Aortic Arch Branches

-Brachiocephalic Trunk

-Left Carotid Artery

-Left Subclavian Artery

Brachiocephalic Trunk

-Branches into the right subclavian artery (right arm)

-Branches to the right carotid artery (brain and right side of the head and neck)

Left Carotid Artery

-Supplies the brain

-Supplies the left side of the head and neck

Left Subclavian Artery

-Supplies your left arm and the back of your brain

Valves in the heart

-Pulmonary Valve

-Aortic Valve

-Bicuspid Valve

-Tricuspid Valve

Myocardium

Heart muscle

Coronary Arteries

Blood vessels that branch from the aorta and carry oxygen-rich blood to the heart muscle

Chambers

-Right Atrium

-Left Atrium

-Left Ventricle

-Right Ventricle

Veins

Carry deoxygenated blood back to the heart from the body

Pulmonary Vein

Carries oxygenated blood from the lungs to the heart

Arteries

Carry oxygenated blood away from the heart to the body

Pulmonary Artery

Carries deoxygenated blood from the heart to the lungs to pick up oxygen

Vena Cavae (superior and inferior)

-2 largest veins in the body

-Bring deoxygenated blood from all parts of the body back to the right atrium of the heart

Aorta

-Main artery of the body

-Supplies oxygenated blood to the circulatory system and entire body

What is an autopsy?

An autopsy is a thorough examination of a body after death to determine the cause, mechanism, and manner of death.

What are the types of autopsies?

There are three main types of autopsies: forensic (medicolegal), clinical (medical), and academic (anatomical).

What is a forensic autopsy?

A forensic autopsy is performed when a death is related to a suspected crime or is suspicious.

What is a clinical autopsy?

A clinical autopsy is performed when the family wants to know how or why their family member died, and the death is not suspicious.

What is an academic autopsy?

An academic autopsy is performed for educational purposes, such as in teaching hospitals or colleges.

What are the major components of an autopsy?

The major components of an autopsy include identification, external examination, and internal examination with sample collection.

What is the purpose of the identification process in an autopsy?

The identification process involves checking the toe tag and documenting identifying features of the body.

What is the external examination in an autopsy?

The external examination involves observing, documenting, and photographing the condition of the body, measuring and weighing it, and sometimes taking X-rays.

What is the internal examination process in an autopsy?

The internal examination involves making incisions, removing organs, examining them, and obtaining samples before returning the organs and stitching the incision.

What is the mechanism of death?

The mechanism of death refers to the specific physiological event(s) that resulted in death, such as cardiac arrhythmia.

What is the cause of death?

The cause of death is the specific disease, injury, or trauma that led to the mechanism of death, such as a myocardial infarction.

What is the manner of death?

The manner of death describes the circumstances surrounding the death, categorized as natural, unnatural (accidental, homicide, suicide), or undetermined.

What is algor mortis?

Algor mortis is the post-mortem change in body temperature until it matches the ambient temperature, beginning immediately at death.

What is livor mortis?

Livor mortis, or lividity, is the pooling of blood in a body after death due to gravity, becoming apparent after about one hour.

What is rigor mortis?

Rigor mortis is the stiffening of muscles after death, first evident in facial muscles after 1-4 hours and in other muscles after 6-12 hours.

What is the significance of cloudy corneas after death?

Cloudiness of the corneas begins approximately two hours after death and is a sign of post-mortem changes.

What is decomposition?

Decomposition is the breakdown of the body's tissues after death, impacted by variables such as insects and bacteria.

What are the stages of decomposition?

The stages of decomposition include Fresh/Autolysis, Bloat, Active Decay, Advanced Decay, and Skeletonization.

What occurs during the Fresh/Autolysis stage of decomposition?

During the Fresh/Autolysis stage, algor mortis, livor mortis, and rigor mortis occur, and enzymes begin to rupture cells.

What happens during the Bloat stage of decomposition?

In the Bloat stage, gases produced by bacteria cause the body to swell, and insect activity increases.

What occurs during the Active and Advanced Decay stages?

During these stages, tissues liquefy, the skin ruptures, and insect activity peaks.

What is the final stage of decomposition?

The final stage, Skeletonization, occurs after about 50 days post-mortem when most soft tissue is gone, leaving only bones.

What is the role of a medical examiner?

A medical examiner is responsible for investigating deaths, performing autopsies, and determining the cause and manner of death.

What factors can complicate determining the time of death?

Factors such as environmental conditions, body position, and the presence of insects can complicate the estimation of time of death.

What is the physiological time of death?

The physiological time of death is when vital functions actually stopped.

What is the estimated time of death?

The estimated time of death is the time the medical examiner estimates that death occurred.

What is the legal time of death?

The legal time of death is recorded on the death certificate, based on when the body was found or pronounced dead.

What is the Time of Death?

The Time of Death refers to the estimated time when a person has died, which can be determined through various forensic methods.

What is forensic toxicology?

Forensic toxicology is the field of science that tests biological samples for the presence of chemicals, alcohol, poisons, metals, and gases to determine their role in suspicious deaths or crimes.

What is forensic chemistry?

Forensic chemistry involves testing non-biological samples, such as powders and pills, to identify their components and concentrations related to suspicious deaths or crimes.

What is toxicology?

Toxicology is the study of the effects of chemicals, including drugs, alcohol, poisons, metals, and gases, on the human body.

What are the major components of a toxicology report?

A toxicology report typically includes positive findings, testing required, specimens received, detailed findings, reference comments, and an analysis summary with reporting limits.

What is the difference between mechanical digestion and chemical digestion?

Mechanical digestion involves the physical breakdown of food into smaller pieces (e.g., chewing), while chemical digestion involves the enzymatic breakdown of food into simpler molecules.

What organs does food pass through in the digestive system?

Food passes through the mouth, esophagus, stomach, small intestine, large intestine, and rectum, with each organ having specific functions in digestion.

What is the overall function of the nervous system?

The overall function of the nervous system is to detect, process, and trigger responses to stimuli.

What is a Traumatic Brain Injury (TBI)?

A Traumatic Brain Injury (TBI) is a disruption in the normal function of the brain caused by a bump, blow, or jolt to the head, or a penetrating head injury.

What is Chronic Traumatic Encephalopathy (CTE)?

Chronic Traumatic Encephalopathy (CTE) is a brain degeneration condition likely caused by repeated head traumas, leading to abnormal protein buildup and nerve tissue death.

What are the four types of tissues in the human body?

The four types of tissues are epithelial tissue, connective tissue, muscle tissue, and nervous tissue.

What is the role of epithelial tissue?

Epithelial tissue serves roles in protection, secretion, and excretion, and is characterized by being anchored on one side and free on the other.

What is the role of connective tissue?

Connective tissue protects, supports, and binds together other body tissues, with each type having specific cells contained within a matrix.

What is the role of muscle tissue?

Muscle tissue is responsible for movement and is composed of elongated contractile cells.

What is the role of nervous tissue?

Nervous tissue detects, processes, and causes responses to stimuli, primarily composed of neurons and supporting cells called neuroglia.