Deck Dr Williams

Question 1

List 5 common toxic fire gases, not including carbon monoxide

Answer 1

Cyanide
Phosgene
Acrolein
Sulfur dioxide
Nitrogen dioxide
Hydrogen chloride
CO2

Question 2

List and describe 5 types of cervical vertebral fractures below C2

Answer 2

Flexion-distraction (injury posterior ligaments, anterior displacement of vertebrae with no fracture)

Flexion-compression (same as flexion distraction, but with anterior and inferior displacement of a vertebrae, causing compression and fracturing of the adjacent vertebra)

Extension distraction (opposite of flexion distraction, no fracture)

Extension compression (opposite of flexion distraction, but with fracture posterior elements)

Vertical compression: compression and fracturing of a vertebra

Question 3

What is the most important factor determining the state of skeletalized remains?

Answer 3

The environment(s) to which they were exposed (much more important than the period of time elapsed since death)

Question 4

list effects of alcohol

Answer 4

CNS depression
Diuresis
Disregulation of heat-regulatory mechanisms (peripheral vasodilation and heat loss)
Electrolyte disturbances
Cerebellar vermal degeneration

Question 5

3 categories of cardiomyopathy

Answer 5

Hypertrophic
Dilated
Restrictive

Question 6

What are the forensic pathology priorities and necessary examinations in airline crashes?

Answer 6

Identification
Determination of COD
Autopsy for pilots/crew
Detection of potential evidence

Question 7

What is an explanation for low levels of cyanide in the blood of a seemingly natural or traumatic death?

Answer 7

Postmortem production, especially if no sodium fluoride added or if stored prolonged before testing

Question 7

Symptoms of diabetes

Answer 7

Polyphagia
Polydypsia
Weight loss
Polyuria

Question 8

Ways to reduce risks in autopsy suite

Answer 8

Staff training
PPE with proper N95 mask
Avoid aerosol
Consider not performing autopsy in certain cases

Question 9

Explain the biochemical changes in the exercise and post-exercise periods that may contribute to sudden death

Answer 9

During:
Sympathetic NS stimulation, leading to increased HR, BP, increased cathecholamines, elevated potassium

Post-exercise:
Cathecholamine levels continue to rise
Potassium levels drop rapidly, leading to hypokalemia

Question 10

List normal oxygen concentration in atmosphere and common symptoms at lower levels

Answer 10

20.9%

10-15%: impaired judgement
8-10%: loss of consciousness
<8% Death

Question 11

What % of ‘drowning’ cases are so-called dry-lung drowning, with normal lung weights?

Answer 11

10-20%

Question 12

Contrast classical findings in hanging vs ligature strangulation

Answer 12

Hanging:
- Uprising ligature mark
- No congestion or petechial hemorrhages

Ligature stangulation:
- Horizontal ligature furrow
- Periligature mark
- Congestion and petechial hemorrhage
- Over or below laryngeal proeminence

Question 13

Radiographic finding in lead poisoning

Answer 13

Lead lines in gums or metaphyseal plate

Question 15

What is the major resistor in the body?

Answer 15

Skin

Question 16

what is methyl alcohol metabolized by and what is the product?

Answer 16

Formaldehyde –> formic acid

Question 17

Give some generalized signs and symptoms of alcohol toxicity at various BACs

Answer 17

over 30 - impaired complex skills
50-100 - loss of inhibition, laughter, sensory disturbance
80 - legal limit for driving in Canada
150-200 - obvious drunkeness, nausea, staggering
200-300 - stupor, vomiting, coma
Over 350 - progressive danger of death from respiratory paralysis

***CAUTION - may case examples of high BAC in surviving and functioning individuals exist, eg. woman surviving 1510 mg/dL, Australian drivers at 500 mg/dL at roadside checkpoint stops….

Question 18

list causes of death for ‘death in dental chair’

Answer 18

Natural causes
Anaesthetic related
- Local anaesthetic related (IV or overadministrtion of drugs)
- Allergic reaction

Question 19

what ECG changes are associated with hypothermia?

Answer 19

Inverted T waves
Prolongation QT

Question 20

What is ‘triple risk’ model of SIDS?

Answer 20

A vulverable infant in a critical period of development with environmental factors (external stressor)

Question 21

What are the 3 conclusions that can be reached with fingerprint comparison?

Answer 21

Positive ID
Exclusion
Inconclusive

Question 22

How many phases are in the Lovejoy assessment of the ilium for age estimation?

Answer 22

8

Question 23

List 4 general categories of deaths during/after surgery

Answer 23

Directly caused by the disease or injury
Disease or abnormality other than for what the procedure was being carried out
Mishap during or complication of rugical or diagnostic procedure
Mishap or complication of the anaesthetic

Question 24

Signs and symptoms of hyponatremia

Answer 24

Nausea Vomiting Headache Weakness Confusion Seizures

Question 25

What is a flash fire? How can it cause death?

Answer 25

Flash: brief flash of fire, due to combustion of vaporised hydrocarbon or rapid consumption of other fire fuel in the air Cause death: - Rapid O2 drop - Co2 and CO rise rapidly - Intense heat

Question 26

Mechanism of death in hydrogen sulfide

Answer 26

production of methemoglobinemia

Question 27

Histo findings in carbon tetrachloride poisoning

Answer 27

Centrilobular necrosis Fatty change Tubular necrosis

Question 28

Metabolism of ingested methanol

Answer 28

Formaldehyde Formic acid

Question 29

What are the common fatal abdominal injuries in children?

Answer 29

Liver laceration Pancreaticoduodenal laceration Mesenteric laceration

Question 30

list 3 of the most common blast injuries

Answer 30

Tympanic membrane rupture Lung injury GI tract rupture

Question 31

What factors most effect insect development?

Answer 31

Temperature Humidity

Question 32

Describe stages of pressure ulcers

Answer 32

1: hyperermia 2 : blister or ulceration of skin, not extending past demis (not subcutaneous fat) 3: ulceration of skin and subcutaneous tissues to level of muscular fascia 4 : up to the bone

Question 33

Which 3 organs are most affected by chronic alcoholism?

Answer 33

Liver (ASH/cirrhosis) Brain (Cardiomyopathy) Heart (hemorrhage and atrophy of mammary bodies, cerebellar vermis degeneration)

Question 34

What is the mechanism of action of organophosphorus pesticides?

Answer 34

Inhibition of cholinesterase

Question 35

what is the mechanism of death in methanol poisoning?

Answer 35

metabolic acidosis

Question 36

what is the mechanism of death in tricyclic antidepressant overdose?

Answer 36

cardiac arrhythmia (widening of QRS, tachycardia, arrhythmia)

Question 37

What is the most common coronary artery anomaly?

Answer 37

Origin of the left coronary from the right sinus

Question 38

What is the most common underlying cause of aortic dissection

Answer 38

Hypertension

Question 39

What is the most common underlying pathology in sudden cardiac death in exercise < 35 years & > 35yrs

Answer 39

< cardiomyopathy, channelopathy, anomalous coronary anatomy

Question 40

What is the most reliable method of age estimation using teeth in adults?

Answer 40

Lamendin method. Useds parodontal disease and translucency of root in monoradicular teeth.

Question 41

What is the nature of C14?

Answer 41

Interaction of a neutron with N14 ( 14N + n → 14C + p) Neutron flux from cosmic rays and/or neutron flux from nuclear fission (bombs, reactors) C14 in atmosphere oxidized to CO2, enters food web via plant biomass and seawater via air-sea exchange

Question 42

What is the pharmacological action of naloxone (Narcan)?

Answer 42

μ-opioid receptor (MOR) inverse agonist κ-opioid receptor (KOR) antagonist δ-opioid receptor (DOR) antagonist

Question 43

what is the pharmacological effect of cocaine?

Answer 43

-inhibits NE reuptake -stimulates NE release -moderate similar effects on serotonin and dopamine -local anesthetic effects via sodium channel blockade

Question 44

What is the proposed mechanism of death in inhaled solvent abuse?

Answer 44

Arrhythmia facilitated by sensitization of myocardium to catecholamines

Question 45

what is the relationship between the concentration of EtOH in the alveolar air and the alveolar capillary plasma?

Answer 45

1:2300

Question 46

what is the relative affinity of CO for Hb compared to O2

Answer 46

CO 200-300x stronger affinity than O2

Question 47

What is the stereotypical position of a body in water?

Answer 47

dorsal torso upward, hands, knees, face downward important to remember as dorsal hands, face, and anterior knees may have postmortem changes related to movements in the water (against floor etc)

Question 48

what is the t1/2 of COHb? what therapy may improve this?

Answer 48

4-6 hours on room air Oxygen therapy 40-80 minutes on normobaric 100% O2 15-30 minutes on hyperbaric O2

Question 49

What is the theory behind diatoms tests in drowning cases?

Answer 49

Diatoms will be aspirated and readily cross alveolar wall into bloodstream - if heart beating then will be delivered to organs (brain, kidney, liver, bone marrow). Extremely resistant to decay, so can dissolve away tissue, including bone, but leave the silicaceous exoskeletons of diatoms for microscopic analysis. If present in significant numbers and of species similar to the body of water where found, then supports drowning. (this method is largely considered debunked for lack of specificity)

Question 50

What is the threshold of contemporary forensic interest in skeletal remains?

Answer 50

70-100 years

Question 51

what level of ethanol can be produced by postmortem decomposition (fermentation)?

Answer 51

Up to 80 mg/dL, some reports up to 220 mg/dL

Question 52

What may be found in electrocutions in bathtub (peculiar postmortem change)?

Answer 52

Hypostasis may stop at level of the water

Question 53

what may be found in starvation at autopsy?

Answer 53

low BMI lack of fat stores (abdominal wall, omentum, mesenteric, epicardial) muscular atrophy edema & effusions may occur ulcerations of colonic mucosa have been described ('pseudo-dysentery')