Forensic Pathology 1 Flashcards
what distance do shotgun wounds show a) central defect, b) scalloped wound, c) central defect w satellite defects, d) individual pellet wounds?
a) 0-2 feet,
b) 2-4 feet,
c) 4-15 feet,
d) >15 feet
what distance does a shotgun wad a) enter the body, b) leave wad mark(abrasion, NOT penetration) on the body?
a) 0-12 feet
b) 12-30 feet(below pellets bc gravity)
What is the half life of CO in a)hyperbaric oxygen, b) 100% oxygen, c) room air?
a) 25 minutes,
b) 90 minutes,
c) 6 hours
What are the histological findings of HIV encephalitis?
p24 antigen immunoreactivity, microglial multinucleated nodules, LITTLE inflammation (bc HIV decreases immune system)
what do inguinal stretch abrasions indicate?
in blunt force injury, that decedent was struck by vehicle at opposite end (i.e. right inguinal stretch abrasions = struck on posterior left)
LEGAL: what is “mens rea”?
principle of a guilty mind
LEGAL: what is “res ipsa loquitur”?
The occurrence of an accident implies negligence
LEGAL: what is “actus rea”?
principle of a guilty act
LEGAL: what is “legal doctrine respondeat superior”?
An employer is responsible for the actions of employees performed in the normal course of duties during their employment
LEGAL: What is a peremptory challenge?
The plaintiff or the defendant in a jury trial can have a juror dismissed before the trial without a stated reason
LEGAL: what is “subpoena duces tecum”?
writ requiring a person to appear in court to give testimony, and to bring documents, books, or other things for the court
What is the most common type of brain herniation and where does it herniate?
Subfalcine (cingulate) herniation: cingulate gyrus of frontal lobe moves under falx cerebri (medial)
Where is transtentorial herniation?
central Temporal lobe/diencephalon, moves inferiorly
when do you see shotgun petals on the body?
between 6 inches and 3 feet (when the petals “fan out”)
What poisoning causes a) brown lividity? b) green lividity?
a) nitrates b) hydrogen sulfide
What common illicit substance inhibits NMDA receptors which bind glutamate? Is it lipid/water/both soluble?
PCP, both lipid and water soluble
What compound is poisonous from “Jimson weed”/Datura stramonium?
anticholinergics (atropine, scopolamine and hyoscyamine)
What compound is poisonous from Rosary Pea and what does it do?
abrin, inhibits protein synthesis
What results in conj petechiae, partial or full suspension hangings?
partial suspension (bc forces occlude the venous return to the heart more than restrict arterial blood flow to the head)
What is despropionylfentanyl and what structural class is it in?
4-ANPP, piperidinamine (NOT opioid). is both precursor and inactive metabolite of fentanyl
What does ammonia and bleach combine to make?
water, sodium chloride, hydrochloric acid (HCl), chlorine gas (Cl2), chorine (Cl-), chloramine (NH2Cl), and hydrazine (N2H4)
Vitamin associations:
what vitamin(s) a) increases iron absorption and can interfere with warfarin, b) interfere with coagulation, c) cause hypercalcemia
a) Vit C,
b) vit K and E,
c) Vit D and A
what is Fitz-Hugh-Curtis syndrome?
result of PID (w N gonorrheae or C. trachomatis), infection travels from pelvis to abdomen and causes adhesion of liver to right hemidiaphragm
Forces causing rapid lateral velocity of the head cause SAH where and by tearing what artery?
base of brain, vertebral artery
What is filler (with GSW) and what kind of injuries does it cause?
white granular substance encased in a shotgun shell WITH the bird/buck shot; causes stippling to 2 - 3 meters
where do a) skin tags and b) skin tears point to in tangential graze GSW?
skin tags point towards the firearm, skin tears point towards the direction of travel of the bullet
what is the most common sarcoma of the heart, and where is it located?
angiosarcoma (in the right atrium, often involves pericardium and causes tamponade)
(rhabdomyosarcoma=most common of childhood)
where is myxoma most commonly located and what mutation is it associated with?
left atrium, PRKAR1A mutation with Carney’s complex/syndrome (myxomas, blue nevis, Schwannomas)
What is the time it takes skin to burn in hot water at: 1) 120F/49C, 2) 125F 3) 140F/60C, 4) 160F/70C
1) 10 min,
2) 2 min,
3) 6 sec,
4) 1 sec
What is Brugada syndrome and what electrolyte abnormalities/genetics are associated with it?
autosomal dominant SCN5A, Na+ channel mutations. sudden cardiac death from arrhythmias
What increases the affinity of hemoglobin for oxygen with: a) temperature,
b) CO,
c) CO2/ acidity/low pH,
d) 2,3 bisphosphoglycerate,
e) methemoglobin
a) decreased temp/hypothermia,
b) increased CO,
c) decreased CO2/high pH,
d) decreased 2,3 BPG,
e) decreased methemoglobin
what drugs are cause of diaphoresis, diarrhea, urination, cough, nasal discharge, vomiting, lacrimation, salivation, bradycardia, and constricted pupils? What is the antidote?
Acetylcholinesterase inhibitors (i.e. organophosphates); atropine is antidote
What does N-acetyl-cysteine replenish in tylenol toxicity and what toxic metabolite does that reduce?
glutathione, which reduces NAPQI (toxic byproduct)
What is Loeffler’s endocarditis?
restrictive cardiomyopathy more common in tropical areas, has hypereosinophilia (like endomyocardial fibrosis but more severe)
How long are a) wet stock tissue and b) paraffin blocks kept in forensic vs non-forensic autopsies?
a) 1 year(forensic), 3 months (non-forensic),
b) indefinitely (forensic), 10 years (non-forensic)
How long are a) microscopic slides, b) reports, c) body fluids & tissue for tox kept in forensic vs non-forensic autopsies?
a) indefinitely (forensic), 10 years (non-forensic),
b) indefinitely (forensic), 10 years (non-forensic),
c) 1 year (forensic), N/A (non-forensic)
NAME maximum SUGGESTED and REQUIRED autopsies per year
suggested: 250,
required: 325
What type of brain herniation is associated with Duret hemorrhages?
transtentorial/uncal herniation
What is a primary blast injury and where are they common in air vs water?
blast wave injuries; in air to the ear and airway, in water to the abdomen
What are a) secondary blast injuries, b) tertiary, and c) quaternary blast injuries?
a) flying debris hitting the body from a blast
b) body in motion striking an object (i.e. wall)
c) burns from fire from a blast or building collapsing on a person
What is Stanford A and Stanford B dissection?
A) ascending +/- descending
B) descending
What is DeBakey I, II, IIIA, and IIIB aortic dissection?
I) ascending + descending
II) ascending
IIIA) descending, extending prox and distal
IIIB) descending, extending distal
What is the most common primary tumor of heart in children?
rhabdomyoma, 50% in association w tuberous sclerosus (while rhadomyoSARComa is most common sarcoma of childhood)
How much stronger is the hemoglobin affinity for CO than O2, and what percent carboxyhemoglobin do you see cherry-red lividity?
250-300x, and >=30%
What is the a) Daubert standard, and b) Frye standard?
a) admissibility of scientific evidence is the responsibility of the judge,
b) scientific principles must be sufficiently established to have gained general acceptance in the particular field in which it belongs
What is rule 702?
Federal Rules of Evidence: expert may give an opinion if 1. The expert’s knowledge will help to understand a fact or evidence, 2. The testimony is based on sufficient data, 3. The testimony is based on reliable principles, and 4. The expert has reliably applied the principles to the case
What specific electrolyte imbalance from bulimia causes death?
hypokalemia (arrythmias)
What cocaine metabolite is metabolically active?
norcocaine
What causes false positive amphetamine screen?
nasal decongestions (ephedrine, pseudo, phenylephrine), antihistamines, some antidepressants(buproprion & trazodone), some antipsychotics (promethazine, chlorpromazine)
How much % blood volume loss is a) class I hemorrhage, b) class IV hemorrhage
a) <15% blood volume loss
b) >40% blood volume loss (class IV=increased risk of dying by exanguination alone)
what causes death with acute altitude/mountain sickness?
pulmonary and cerebral edema
what treats a) cyanide toxicity, b) ethylene glycol/methanol
a) amyl nitrate
b) fomepizole
what environmental element causes intestinal type sinonasal adenocarcinoma?
wood dust
What neurotransmitter change is associated with sudden infant death?
decreased serotonin
How many milliamps of electrical current cause a) tingling sensation, b) painful shock, c) muscular contraction forcing victim to hold on to the electrical force, d) v fib?
a) 1 milliamp,
b) 5 milliamps
c) 16 milliamps
d) 100 milliamps
what are gun cartridge casings made of?
brass (alloy of zinc and copper)
what are most primers (in ammo) made from?
barium, antimony, lead
what is black powder composed of?
potassium nitrate, sulfur and charcoal
What elements are bleach made up of?
NaO- Cl+
What are at least 4 encapsulated organisms that would cause infection in someone with sickle cell anemia?
SHiNE SKiS: Strep pneumo, H flu, N. meningitidis, E Coli, Salmonella, Klebsiella, Group B streptococcus (agalacticae)
How many pounds of pressure does it take to compress the a) jugular veins, b) carotid arteries, c) trachea, d) vertebrals
a) 4.4,
b) 11,
c) 33,
d) 66
What is the Widmark equation?
% BAC = (A x 5.14 / W x r) - 0.015 x H, where A = ounces of alcohol consumed(as equal to 100%), W = weight in pounds, r = gender constant of alcohol distribution (0.73 for men and 0.66 for women), H = hours elapsed.
what symptoms do organophosphates cause?
parasympathetic activation (rest and digest): diarrhea, urination, cough, nasal discharge, vomiting, lacrimation, bradycardia, miosis
(acetylcholinesterase inhibitors)
what is the chemical compound found in glue (glue sniffing) and what electrolyte change does it cause?
toluene (methylbenzene), hypokalemia with metabolic acidosis (& distal renal tubule acidosis)
What are carbon monoxide levels usually in a) house fires, b) car exhaust deaths?
a) 50-60%,
b) >70%
What are CO levels in a) non-smoking, non-city dwellers, b) non-smoking urban dwellers, c) smokers?
a) 0.4-0.7%,
b)1-2%,
c) 3-10%
How many permanent teeth are there and how are they labeled? How many deciduous teeth?
32, with #1 being upper right molar, #17 being lower left molar (moving in that sequence)
20 deciduous
What antidotes are given in a) lead and b) thallium poisoning respectively?
a) EDTA,
b) Prussian blue
What is the different in the rule of nines (burns) in children as opposed to adults?
18% instead of 9% for entire head, 14% instead of 18% for each leg
What is a) beer potomania and what symptoms would you see? vs b) Wernicke Kosakoff syndrome?
a) hyponatremia from solute/protein underconsumption: lethargy, AMS, gait disturbance
b) thiamine deficiency, with Wernicke: opthalmoplegia (weakness of eye muscles), dementia, ataxia; Kosakoff: anterograde amnesia
LEGAL: what is voir dire?
preliminary examination of witness/jury by a judge/counsel
what do formic and sulfuric acid combine to make?
carbon monoxide
How many petals does a regular shotgun’s plastic sleeve/wadding have, except for what kind?
4 petals, except for the 0.410 (smallest gauge) which has 3 petals
what does codeine metabolize into and through what mechanism in liver?
morphine, by CYP450 2D6
what is Marchiafava-Bignami disease?
demyelinization of corpus callosum, usually seen with chronic alcoholism
(“big margarita corpus”)
What is the 1) first and 2) last bone to undergo epiphyseal fusion?
1) humerus (9-15 y),
2) medial aspect of clavicle (19-30 y)
What conditions are associated with cortical laminal necrosis?
hypoglycemia, status epilepticus, hypoxia & ischemia including stroke
What metal poisoning is associated with dialysis patients and has symptoms of AMS, muscle weakness, bone pain/osteoporosis?
aluminum poisoning
What metal poisoning is associated with peripheral neuropathy, skin desquamation/discoloration, sympathomimetic symptoms(increased BP, epinephrine), AKI/ATN, hemorrhagic colitis, tooth/hair loss?
mercury poisoning
What is PCR amplification of amelogenin useful for?
determination of sex (of skeleton)
- inclusive and a probability is given if all loci match, exclusive if one or more do not match, or inconclusive if all loci match but the probability is low
What metal poisoning is associated with headaches, confusion, somnolence, diarrhea, acute hemolytic anemia, white lines on fingernails?
arsenic poisoning
HOCM: how much wider should IVS be than LV for diagnosis? WHat is HOCM also known as?
1.3x,
idiopathic hypertrophic subaortic stenosis (IHSS)
When does peripartum cardiomyopathy tend to occur and what is it?
In third trimester or first 6 months post-partum; a dilated cardiomyopathy
Where are AVMs generally found in the brain?
area of MCA blood flow (followed by midbrain, cerebellum, spinal cord)
What tumor is found in the a) fourth ventricle (central to cerebellum) and b) what tumor is found in the third ventricle?
a) subependymoma,
b) colloid cyst (remember it can cause hydrocephalus, and acellular cyst contents are PAS-positive)
What is Schmidt syndrome, and what should you worry as the immediate COD in it (if presenting symptoms leading to death include flu-like illness)?
type II polyglandular autoimmune syndrome (2+ autoimmune disease such as T1DM, Hashimoto’s, etc); acute Addisonian crisis with adrenal hypoplasia (measure cortisol!)
what is the mechanism of helium, methane, and nitrous oxide use?
helium and methane: O2 displacement,
Nitrous oxide: chemical pneumonitis
What does sertraline cause a false positive for in a standard urine drug screen?
benzodiazepines
What do venlafaxine and dextromethophran cause a false positive as?
PCP
(D and P in V)
What drugs cause false positive drug screen for methadone?
ibuprofen, some antipsychotics, antihistamines, the Ca+2 channel blocker verapamil, clomipramine (antidep)
What drugs can cause false positive drug screen for cannabinoids and barbituates?
NSAIDS ibuprofen and naproxen
What abnormalities can you see on ECG for a) digoxin, b) antipsychotics, c) TCAs?
a) heart block,
b) prolong QT interval,
c) widen QRS complex
What blood collection tubes are best for a) DNA analysis, A1c, CBC, b) serum chemistry/serology/ABO typing, c) chromosome analysis, CO, NH3,
d) alcohol/drug/glucose testing,
e) coagulation studies & heavy metals/trace elements
a) EDTA (purple top),
b) red top (silicon-you know it’s chemistry bc of vitreous)
c) heparin (green top),
d) NaF/K-oxalate (grey top=SALT, margarita w sugar/bananas)
e) citrate (blue top)
What is Ohm’s law?
V=IR
(voltage = current x resistance)
What can cause false positive drug screen for opiates?
quinolone antibiotics
With what kind of guns and bullet qualities do you see sympathetic discharges (two bullets fire with one pull of trigger) with?
revolver with rimfire (most commonly 0.22) ammunition. the 2nd bullet travels out of the side of the weapon so it has no rifling & part of the bullet is seared off
What is axial loading and what kind of fractures happen with it?
head hitting surface perpendicularly i.e. diving in shallow water or head hitting ceiling of automobile.
Atlas (C1) fracture
What happens to cyanide if its not put in grey top (NaF) top tube, and what happens to it with embalming?
CN can increase or decrease post-mortem if not put in grey top tube, and is destroyed by embalming
What are a) benzos and b) barbituates’ mechanism of action?
a) increase frequency of Cl- channel opening by binding to GABA-A receptors
b) increase duration of Cl- channel opening by binding to GABA-A receptors & block AMPA receptor (glutamate)
What is a) amphetamines’ and b) cocaine’s mechanism of action?
a) monoamine (NE, DA, SE) release AND reuptake inhibitor.
b) blocks dopamine, serotonin and norepinephrine reuptake, and block Na+ channels
What is Ebstein’s anomaly / what are the findings?
congenital heart defect where tricuspid valve’s septal and posterior leaflets are displaced downwards towards the apex. See atrialization of RV, endocardial fibroelastosis of RA&RV
what is difference between endomyocardial fibrosis and endocardial fibroelastosis?
endoMyocardial fibrosis (M=Marshall Islands, tropical areas, eosinophilic restrictive cardiomyopathy.
endocardial fibroelastosis: found in kids under age 3, NO eosinophils
Color change of sodium rhodizonate to pink then blue indicates the presence of what?
lead
What gas causes a chemical pneumonitis?
Nitrogen dioxide, the primary gas formed in silos (“sillage gas”), hydrolyzes in the respiratory tract to nitrous acid and nitric acid
wedge fracture: how can you tell direction of the force?
from the broad edge of the fracture to the point
What findings should you look for with acceleration-deceleration injury?
diffuse axonal injury - petechial hemorrhages may be centered in the corpus callosum
what ranges do you see stippling with flake vs spherical gunpowder?
Flake powder: 18 to 24 inches,
spherical powder: 36 to 42 inches
What are the 2 categories of rifles?
rimfire (low power, 0.22); and centerfire (high power, most others in this category)
What is the significance of a stellate vs slit-like exit wound?
slit like = low velocity, the projectile may still be in the vicinity of the decedent’s body
What is not seen on xray from projectiles?
aluminum jackets, the blue cap of a Glaser safety slug
What is the range for a) small, b) medium, and c) large caliber projectiles?
a) 0.22-0.25,
b) 0.32-0.40, 9 and 10 mm,
c) 0.44 - 0.50
Small uniform projectiles on xray diff dx?
birdshot, Glaser safety slugs (frangible bullets), and ratshot/snakeshot
What are cathiones (drugs)
bath salts (stimulants)
What CNS complication that results in death can you see in eclampsia?
intracranial hemorrhage
What other stains besides congo red will stain for amyloid?
methyl violet, thioflavin T or S with UV light, Alcian blue
What is histiocytoid cardiomyopathy, where you see multifocal yellow-tan nodular lesions/plaques?
seen in girls <2, sheets histiocytoid cells fill myocardium & are +desmin, myoglobin. thought to originate from Purkinje cells
how fast does loss of consciousness occur with compression of carotid arteries, and death?
LOC: 5-10 seconds;
death: 3-5 minutes
Drowning is defined as asphyxia within how many hours of water submersion? Aspiration of how much water impairs gas exchange?
24 hrs; 1-3 mL/kg
What gross change does prolonged CNS damage (i.e. from near drowning, but is non-specific) cause in the brain?
laminar necrosis: thinning of grey matter
What would be the cause of a cerebral artery gas embolism?
SCUBA diving –> extra-alveolar air syndrome, during ascent
How is pneumothorax assessed for at autopsy?
Erlenmeyer flask partially filled with water, put glass tube into it and into a needle going into the body, other whole is left open; air will bubble in flask
What is the range of voltage for high voltage electrocutions?
600-1000 volts
What are the physiologic effects of envenomation from hymenoptera?
hemolysis, rhadbdomyolysis, hepatocellular & myocardial necrosis ->shock
What are the physiologic effects from a) pit vipers (rattlesnakes), and b) coral snakes?
a) compartment syndrome, shock (from hemohhagic/neurotoxic enzymes),
b) CNS paralysis inc respiratory paralysis (from neurotoxin)
What are the physiologic effects from a) brown recluse spiders, and b) black widow spiders?
a) necrotic ulcer-> necrotizing fascitis, DIC from hyaluronidase, alkaline phosphatase, sphingomyelinase D (freeze ulcered skin for ELISA testing),
b) target-like lesion->autonomic nervous system dysfunction (N/V, HTN, tachy) from neurotoxin alpha-latrotoxin (rarely fatal)
What does diffuse axonal injury look like grossly?
Intraparenchymal punctate hemorrhages in brain & brainstem
difference between stun guns and tasers?
stun gun requires placement of electrodes directly against subject (& will see 2 small dots 2 cm apart on skin), taser shoots two electrodes out from gun-like device (two small puncture wounds)
What does Bielschowsky stain highlight in the brain?
Silver stain (yellow background, black cells) for IDing neurofibrillary tangles and neuronal (senile) plaques
What does Ziehl-Neelsen stain highlight?
Acid fast:
Mycobacterium, histoplasma,blastomyces
What is the most common organism of necrotizing fasciitis?
Strep pyogenes (group A strep)
What histology is seen in the brain with multiple sclerosis?
Periventricular leukomalacia: demyelination (brown-pink discoloration) of the white matter adjacent to the lateral ventricles
What is 2-chlorobenzylidene malonitrile?
CS gas, used by police as riot control argent, potent lacrimator, NO associated deaths/safest one
What is lidocaine metabolized to and what is its relevance?
MEGX (monoethylglycinexylidide) and GX (glucinexylidide), can cause seizures i.e. in liposuction surgeries where it is injected directly into fat
What is minimum velocity associated with high explosives, and what is the most common COD for those who initially survive?
> 3300 ft/sec,
Pulmonary injury (blast lung)
What is chemical asphyxia vs suffocation?
Chemical: a compound prevents utilization of oxygen (ie CO, H2S making methemoglobin)
Suffocation: failure of O2 to reach the blood (inc anoxia and hypoxia)
What are findings related to disorder of fatty acid oxidation in a newborn?
hepatic microvesicular steatosis, low carnitine concentration, glucose depletion
What are some autopsy findings seen in SIDS?
perioral/perinasal blood-tinged fluid, intrathoracic petechiae (NOT skin/conj petechiae which would be more asphyxial, BUT often not seen in infant asphyxia either)
What is the most common CNS finding on autopsy with cerebral palsy?
hydrocephalus
What is 1) type 1, 2) type 2, 3) type 3 Chiari malformation?
1) displacement of cerebellar tonsils into foramen magnum; asymptomatic (chronic tonsillar herniation),
2) elongation of cerebellar vermis and brainstem with their displacement into cervical canal; often with hydrocephalus –> polygyria, and spina bifida,
3) elongation + kinking of brainstem & lumbar spina bifida
What is Dandy-Walker malformation?
1) agenesis of cerebellar vermis,
2) enlargement of posterior cranial fossa (UNLIKE Chiari),
3) cystic dilatation of fourth ventricle
(can also be with hydrocephalus, polygyria, agenesis of corpus callosum)
What is external hydrocephalus?
excessive CSF in subarachnoid space (not ventricular system), i.e. in cerebral atrophy
Where is acute myocarditis in infants most common anatomically?
anterior inferior segment of the interatrial septum
What specimens do you save to test for long QT syndrome?
EDTA-preserved blood and/or heart/liver/spleen frash-frozen and stored at -80 deg C
What is Brugada syndrome?
aut dom disorder associated with cardiac Na+ channels
What is example of a) hypertonic, b) isotonic, and c) hypotonic dehydration?
a) high Na+, with water deprivation/loss and DM, most common in neglect,
b) normal Na+, with viral diarrhea, most common form
c) low Na+, cystic fibrosis
all usually have high BUN/Cr additionally
What is a known complication seen with severe dehydration (that is in the head)?
thrombosis of superior sagittal sinus
hypoglycemia, diffuse microvesicular hepatosteatosis, and cerebral edema with neuronal degeneration in a child: think what etiology?
Reye’s syndrome
What findings should you look for in child with sickle cell disease (signs of vasoocclusive crisis)?
cerebral or cardiac infarct from microthrombi; atrophied & fibrotic spleen
What 5 findings are seen in Kawasaki disease?
1) rash / lip fissures / strawberry tongue
2) injected conjunctivae
3) cervical lymphadenopathy
4) multisystem vasculitis (with dense inflammation, necrosis/fibrinoid change of vessels)
5) aneurysms/artery thrombosis –> (** think of this for MI in kids**), complete heart block
What is caveat emptor (LEGAL)?
buyer alone is reponsible for checking quality of goods before a purchase is made
