Deck Dr Williams Flashcards
List 5 common toxic fire gases, not including carbon monoxide
Cyanide
Phosgene
Acrolein
Sulfur dioxide
Nitrogen dioxide
Hydrogen chloride
CO2
List and describe 5 types of cervical vertebral fractures below C2
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
What is the most important factor determining the state of skeletalized remains?
The environment(s) to which they were exposed (much more important than the period of time elapsed since death)
list effects of alcohol
CNS depression
Diuresis
Disregulation of heat-regulatory mechanisms (peripheral vasodilation and heat loss)
Electrolyte disturbances
Cerebellar vermal degeneration
3 categories of cardiomyopathy
Hypertrophic
Dilated
Restrictive
What are the forensic pathology priorities and necessary examinations in airline crashes?
Identification
Determination of COD
Autopsy for pilots/crew
Detection of potential evidence
What is an explanation for low levels of cyanide in the blood of a seemingly natural or traumatic death?
Postmortem production, especially if no sodium fluoride added or if stored prolonged before testing
Symptoms of diabetes
Polyphagia
Polydypsia
Weight loss
Polyuria
Ways to reduce risks in autopsy suite
Staff training
PPE with proper N95 mask
Avoid aerosol
Consider not performing autopsy in certain cases
Explain the biochemical changes in the exercise and post-exercise periods that may contribute to sudden death
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
List normal oxygen concentration in atmosphere and common symptoms at lower levels
20.9%
10-15%: impaired judgement
8-10%: loss of consciousness
<8% Death
What % of ‘drowning’ cases are so-called dry-lung drowning, with normal lung weights?
10-20%
Contrast classical findings in hanging vs ligature strangulation
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
Radiographic finding in lead poisoning
Lead lines in gums or metaphyseal plate
What is the major resistor in the body?
Skin
what is methyl alcohol metabolized by and what is the product?
Formaldehyde –> formic acid
Give some generalized signs and symptoms of alcohol toxicity at various BACs
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….
list causes of death for ‘death in dental chair’
Natural causes
Anaesthetic related
- Local anaesthetic related (IV or overadministrtion of drugs)
- Allergic reaction
what ECG changes are associated with hypothermia?
Inverted T waves
Prolongation QT
What is ‘triple risk’ model of SIDS?
A vulverable infant in a critical period of development with environmental factors (external stressor)
What are the 3 conclusions that can be reached with fingerprint comparison?
Positive ID
Exclusion
Inconclusive
How many phases are in the Lovejoy assessment of the ilium for age estimation?
8
List 4 general categories of deaths during/after surgery
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
Signs and symptoms of hyponatremia
Nausea
Vomiting
Headache
Weakness
Confusion
Seizures
What is a flash fire? How can it cause death?
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
Mechanism of death in hydrogen sulfide
production of methemoglobinemia
Histo findings in carbon tetrachloride poisoning
Centrilobular necrosis
Fatty change
Tubular necrosis
Metabolism of ingested methanol
Formaldehyde
Formic acid
What are the common fatal abdominal injuries in children?
Liver laceration
Pancreaticoduodenal laceration
Mesenteric laceration
list 3 of the most common blast injuries
Tympanic membrane rupture
Lung injury
GI tract rupture
What factors most effect insect development?
Temperature
Humidity
Describe stages of pressure ulcers
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
Which 3 organs are most affected by chronic alcoholism?
Liver (ASH/cirrhosis)
Brain (Cardiomyopathy)
Heart (hemorrhage and atrophy of mammary bodies, cerebellar vermis degeneration)
What is the mechanism of action of organophosphorus pesticides?
Inhibition of cholinesterase
what is the mechanism of death in methanol poisoning?
metabolic acidosis
what is the mechanism of death in tricyclic antidepressant overdose?
cardiac arrhythmia (widening of QRS, tachycardia, arrhythmia)
What is the most common coronary artery anomaly?
Origin of the left coronary from the right sinus
What is the most common underlying cause of aortic dissection
Hypertension
What is the most common underlying pathology in sudden cardiac death in exercise < 35 years & > 35yrs
< cardiomyopathy, channelopathy, anomalous coronary anatomy
What is the most reliable method of age estimation using teeth in adults?
Lamendin method. Useds parodontal disease and translucency of root in monoradicular teeth.
What is the nature of C14?
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
What is the pharmacological action of naloxone (Narcan)?
μ-opioid receptor (MOR) inverse agonist
κ-opioid receptor (KOR) antagonist
δ-opioid receptor (DOR) antagonist
what is the pharmacological effect of cocaine?
-inhibits NE reuptake
-stimulates NE release
-moderate similar effects on serotonin and dopamine
-local anesthetic effects via sodium channel blockade
What is the proposed mechanism of death in inhaled solvent abuse?
Arrhythmia facilitated by sensitization of myocardium to catecholamines
what is the relationship between the concentration of EtOH in the alveolar air and the alveolar capillary plasma?
1:2300
what is the relative affinity of CO for Hb compared to O2
CO 200-300x stronger affinity than O2
What is the stereotypical position of a body in water?
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)
what is the t1/2 of COHb? what therapy may improve this?
4-6 hours on room air
Oxygen therapy
40-80 minutes on normobaric 100% O2
15-30 minutes on hyperbaric O2
What is the theory behind diatoms tests in drowning cases?
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)
What is the threshold of contemporary forensic interest in skeletal remains?
70-100 years
what level of ethanol can be produced by postmortem decomposition (fermentation)?
Up to 80 mg/dL, some reports up to 220 mg/dL
What may be found in electrocutions in bathtub (peculiar postmortem change)?
Hypostasis may stop at level of the water
what may be found in starvation at autopsy?
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’)
