Chapter 7 - Environmental Pathology Flashcards
(125 cards)
0
Q
What is the most important preventable cause of death in the United States?
A
Smoking: most important preventable cause of death in United States
1
Q
What is the leading cause of premature death in developed countries?
A
Tobacco use leading cause of premature death in developed countries
2
Q
What is nicotine?
A
Nicotine: addictive component in tobacco
3
Q
Besides addiction, nicotine patch can be used to treat what?
A
Nicotine patch used to Rx ulcerative colitis
4
Q
What is cotinine?
A
Cotinine: nicotine metabolite; used for screening
5
Q
What does tar in cigarette smoke contain?
A
Tar contains carcinogenic agents
6
Q
What are the carcinogens in cigarette smoke?
A
Carcinogens: polycyclic hydrocarbons, phenol, nitrosamine
7
Q
What can smokeless tobacco cause?
A
Smokeless tobacco: addictive; ↑risk for oral squamous cancer
8
Q
What does passive smoke increase the risk of in children?
A
Passive smoke: ↑risk of respiratory/middle ear infections in children
9
Q
What does secondhand smoke exacerbate in children?
A
Smoking exacerbates asthma
10
Q
What does passive smoke increase the risk for in adults?
A
Passive smoke: risk for lung cancer; CAD
11
Q
What are the beneficial effects of smoking cessation?
A
Live longer; ↓risk for heart disease, lung cancer, stroke
12
Q
What is the most common recreational drug taken in the U.S.?
A
Alcohol MC recreational drug
13
Q
Where is alcohol metabolized and reabsorbed?
A
Stomach/liver metabolize alcohol; stomach/small bowel reabsorb alcohol
14
Q
Why are women at risk for acute/chronic alcohol complications?
A
Women at risk for acute/chronic alcohol complications; ↓alcohol dehydrogenase
15
Q
What are the enzymes that metabolize alcohol?
A
Enzymes metabolizing alcohol: alcohol dehydrogenase, CYP2E1, catalase
16
Q
What is the rate-limiting enzyme in alcohol metabolism?
A
ADH: rate-limiting enzyme in alcohol metabolism
17
Q
What is key to lab abnormalities in alcohol metabolism?
A
↑NADH key to lab abnormalities
18
Q
How does role of increased NADH in alcohol metabolism?
A
↑NADH: ↑synthesis lactic/β-OHB acids; ↑liver TG synthesis
19
Q
Acetyl CoA is used to synthesize what?
A
Acetyl CoA used to synthesize fatty acids/ketoacids
20
Q
Describe why there is increased risk for fasting hypoglycemia in alcohol metabolism.
A
NADH enhances pyruvate conversion to lactate → ↓pyruvate → fasting hypoglycemia
21
Q
What anions are present in the increased anion gap metabolic acidosis of alcohol abuse?
A
↑Anion gap metabolic acidosis: lactic acid, β-OHB acid
22
Q
Which ketone is not detected with standard urine/blood tests for ketone bodies?
A
β-OHB not detected with standard urine/blood tests for ketone bodies
23
Q
Besides fasting hypoglycemia and acidosis, what are the other laboratory findings in alcohol abuse/alcoholic liver disease?
A
Lactic acid/β-OHB → hyperuricemia (potential for gout); hypertriglyceridemia
Alcohol liver disease: AST > ALT; ↑GGT
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What is the most common systemic complication of IVDU?
Hepatitis C: MC systemic complication of IVDU
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What are the effects of acetaminophen overdose?
Acetaminophen: chemical hepatitis; renal papillary necrosis
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What are the general symptoms of aspirin overdose?
Aspirin: tinnitus, vertigo, tachypnea
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What is the initial acid-base disorder in aspirin overdose?
Initial respiratory alkalosis
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What is the mixed acid-base disorder in aspirin overdose in adults?
Mixed primary respiratory alkalosis and metabolic acidosis (adults)
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What is there danger of in salicylate poisoning?
Salicylate poisoning: danger of hyperthermia
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Both acetaminophen and aspirin toxicity may cause what?
Both acetaminophen and aspirin toxicity may cause fulminant hepatitis
31
Unopposed estrogen increases the risk for what?
Unopposed estrogen: adenocarcinoma endometrium/breast
Risk venous thromboembolism; intrahepatic cholestasis
Risk myocardial infarction/stroke
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OCPs increase the risk for what?
OCP: risk breast adenocarcinoma, cervical SCC
Risk folic acid deficiency (macrocytic anemia)
OCP MCC hypertension in young women → ↑angiotensinogen → ↑ATII
Risk hepatic adenoma causing intraperitoneal hemorrhage
Risk of intrahepatic cholestasis/cholesterol gallstones
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What is the most common cause of death due to a venomous bite?
Bee/wasp/hornet sting: MCC death due to a venomous bite
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What is a contusion?
Contusion: blunt force injury to blood vessels with blood leaking into tissue
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What is an abrasion?
Abrasion: superficial excoriation of epidermis
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What is a laceration?
Laceration: jagged tear with intact bridging vessels/nerves/connective tissue
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What is an incision?
Incision: wound with sharp margins; severed blood vessels
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Describe contact gunshot wounds.
Contact wound: stellate-shaped; fouling (soot + gunpowder)
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Describe an intermediate-range gunshot wound.
Intermediate-range wound: powder tattooing
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Describe a long-range gunshot wound.
Long-range wound: no powder tattooing
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Describe exit gunshot wounds.
Exit wounds: larger than entrance wound
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What is the most common cause of death ages 1 to 44 years?
MVAs MCC death ages 1 to 44 years
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What accounts for more than 50% of deaths from child abuse?
Shaken baby syndrome: >50% deaths from child abuse
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What is the key finding in shaken baby syndrome?
Key finding: retinal hemorrhages
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What is the most common cause of burns?
MCC burns is fire
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What is the most common site for burns?
MC site for burn is upper extremities
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What is the common denominator in all burns?
Common denominator in burns is protein denaturation
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What does the center of a burn have?
Center of burn has irreversible coagulation necrosis
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Describe the zone of ischemia of a burn.
Zone of ischemia has reduction in dermal microcirculation
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Describe the zone of hyperemia in a burn.
Zone of hyperemia due to immediate and transient increase in perfusion
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What does the depth of a burn determine?
Depth of burn determines potential for skin regeneration
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What are the sources for skin regeneration?
Sources for skin regeneration: basal layer of cells at margins; dermal skin appendages
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What is a first degree burn?
1st degree burn: limited to epidermis
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What is a superficial second-degree burn?
2nd degree superficial: extends into papillary dermis; partial-thickness burn
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What is a deep second-degree burn?
2nd degree deep: extends into reticular dermis; partial-thickness burn
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What is a third-degree burn?
3rd degree burn: extends through epidermis/dermis; full-thickness
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What common occurs following a third-degree burn? What can potentially develop?
SCC risk in keloids
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What is a fourth-degree burn?
4th degree burn: extends thru skin, subcutaneous fat, muscle/bone
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What is a possible effect of losing plasma from the burn surface?
Hypovolemic shock from loss of plasma; pitting edema
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What is the most common cause of infection of a burn wound?
P. aeruginosa MCC infection of burn wound
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What may develop in the small intestine as a complication of a severe burn?
Curling ulcers of proximal duodenum
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What is hypermetabolic syndrome?
Hypermetabolic syndrome: heat loss from damaged skin surface → ↑BMR
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Smoke inhalation may result in what type of poisoning?
Smoke inhalation: CO/CN poisoning
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What is heat edema?
Heat edema: mild swelling feet, ankles, hands
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What is heat edema due to?
Cutaneous vasodilation with gravitational pooling
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Who is affected by heat edema?
Elderly in tropical/semitropical area; healthy traveler coming from cold to hot area
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What are heat cramps?
Heat cramps: painful, spasmodic muscle contractions postexercise
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Describe the electrolyte derangement in heat cramps.
Deficiency Na+, Cl−, and fluids in muscle
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What is heat exhaustion?
Heat exhaustion: volume depletion under conditions of heat stress
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What are the clinical findings in heat exhaustion?
Heat exhaustion: <104° F); profuse sweating/no mental status changes
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Describe the laboratory findings in heat exhaustion.
Hemoconcentration, variable serum Na+
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What are the predisposing factors for heatstroke?
CHS: high ambient temperature; poor, elderly without air-conditioning
CHS: chronic disorders (psychiatric, alcoholism) requiring medication
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What are the clinical findings in classic heatstroke?
Core body temp >40° C (104° F); skin hot/dry; mental status abnormal; CNS dysfunction
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What are the laboratory findings in classic heatstroke?
Mild respiratory alkalosis; mild ↑serum CK
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What are the predisposing factors for exertional heatstroke?
EHS: athletes/military recruits; endogenous heat production overrides cooling mechanisms
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What are the clinical findings in exertional heatstroke?
EHS: Core body temp >40° C (104° F); profuse sweating; severe CNS dysfunction
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What are the lab findings in exertional heatstroke?
Lactic acidosis, rhabdomyolysis, ARF, DIC, liver damage, hypocalcemia
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What is the most common freezing injury to tissue?
Frostbite MC freezing injury to tissue
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What is trench foot/immersion foot?
Trench foot/immersion foot: nonfreezing injury; exposure to wet cold
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What is chilblain?
Chilblain: nonfreezing injury; exposure to dry cold
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What is the pathogenesis of frostbite?
Frostbite: tissue exposed to temperature <0° C
Frostbite: ice crystallization; stasis of blood flow
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What occurs during the prefreeze phase of frostbite?
Prefreeze: endothelial plasma leakage; vasoconstriction; ↑plasma viscosity
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What occurs during the freeze-thaw phase of frostbite?
Freeze-thaw phase: extracellular ice crystallization; intracellular volume depletion → death
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What occurs during the postthaw phase of frostbite?
Postthaw: microvascular collapse → necrosis
85
Describe the epidemiology of electrical injury.
Most injuries in children or work-related
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What is the main determinant of tissue injury in electrical injury?
Current main determinant of tissue injury
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What is Ohm's law?
Ohm’s law: Current (I) = Voltage (V)/Resistance (R)
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What change in resistance or voltage results in a decrease in current?
↑Resistance (R) or ↓Voltage (V) = ↓Current (I)
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What change in resistance or voltage results in an increase in current?
↓Resistance (R) or ↑Voltage (V) = ↑Current (I)
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How does AC exposure compare to DC exposure at the same voltage?
AC 3× more dangerous that DC at same voltage
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How do muscle contractions differ during AC and DC exposure?
AC induces tetanic contractions (hold on); DC induces single muscle spasm (throws away)
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How does wet skin affect resistance and current?
Wet skin ↓R causing ↑I
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How does dry skin affect resistance and current?
Dry skin ↑R causing ↓I
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What is the most common cause of death in an electrical injury?
Cardiorespiratory arrest MCC death electrical injury
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What is the most common cause of death from lightening injury?
Cardiorespiratory arrest MCC death from lightening injury
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Who is most at risk for drowning?
Children 1 to 4 and 10 to 14 years old most at risk for drowning
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Define drowning.
Drowning: death by suffocation from immersion in a liquid
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What is wet drowning?
Wet drowning: aspiration of water; MC type of drowning
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What is immersion syndrome?
Immersion syndrome: sudden death from submersion in cold water; vagally mediated cardiac arrest
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What is dry drowning?
Dry drowning: asphyxia from laryngospasm without aspiration
101
Describe two features of the diving reflex.
Diving reflex protective; shunts blood to vital areas
102
Describe the cause of death in drowning.
Death in drowning: laryngospasm/closed glottis; hypoxemia with respiratory/metabolic acidosis
103
How are O2 concentration and atmospheric pressure affected at high altitude?
High altitude: O2 concentration 21%, ↓atmospheric pressure
104
Describe the effect of hypoxemia at high altitude.
Hypoxemia stimulates peripheral chemoreceptors → respiratory alkalosis
105
Describe the effect of respiratory alkalosis on OBC.
Respiratory alkalosis → activates PFK → ↑2,3-BPG → right-shifted OBC
106
Acute mountain sickness occurs at what elevation?
AMS occurs at elevations >8000 feet (2440 m)
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What are the clinical findings in acute mountain sickness?
Headache, fatigue, dizziness, anorexia, nauseous, insomnia
108
Describe the pulmonary edema in high altitude pulmonary edema.
HAPE: noncardiogenic pulmonary edema
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What are the clinical findings in high altitude cerebral edema?
HACE: ataxia, stupor, coma
110
Give two examples of ionizing radiation.
Ionizing radiation: x-rays, γ-rays
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Describe the pathophysiology of ionizing radiation.
Damage to DNA by hydroxyl free radicals
112
Which tissue is most sensitive to ionizing radiation?
Lymphoid tissue most sensitive to ionizing radiation
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Which tissue is least sensitive to ionizing radiation?
Bone least sensitive to ionizing radiation
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What is the first hematologic sign of total body radiation?
Total body radiation: lymphopenia first hematologic sign
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What are the vascular effects of radiation?
Vascular system: thrombosis/fibrosis; ischemia
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What are the acute integumentary effects of radiation?
Acute—erythema, edema, blisters
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What are the chronic integumentary effects of radiation?
Chronic—radiodermatitis; danger of SCC
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What are the acute and chronic GI effects of radiation?
Acute—diarrhea; chronic—bowel adhesions
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What is the most common cancer caused by radiation?
Acute leukemia MC cancer caused by radiation
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What other cancers are caused by radiation besides acute leukemia?
Other radiation cancers: papillary carcinoma of thyroid, osteogenic sarcoma
121
Describe the pathogenesis of injury with UVB light.
UVB: ↑pyrimidine dimers distort DNA helix
UVB: inactivates p53 suppressor gene; activates RAS proto-oncogene
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What are the general effects of UVB light injury?
Sunburn, actinic (solar) keratosis (danger SCC), corneal burns from skiing
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What are the cancers associated with UVB light injury?
UVB cancers: BCC (MC), SCC, melanoma
124
What type of radiation may cause third-degree burns?
Laser radiation: third-degree burns
