Path: Environmental Pathology

Question 1

How does ozone form and cause pathology?

Answer 1

nitrogen oxides form combustion rxn to make ozone

generates free radicals that injure respiratory and alveolar lining

Question 2

How do sulfur dioxide particulates form and cause pathology?

Answer 2

emitted by coal and oil power plants, industrial processes
less than 10 microns move to alveoli, larger particles trapped by mucociliary defenses
macrophages and neutrophils react

Question 3

What are some physical signs you can look for w CO poisoning?

Answer 3

cherry red lividity

may have soot in oral cavity

Question 4

What are the heavy metals and how do they cause pathology?

Answer 4

found in earth’s crust, often necessary in trace amounts

lead, mercury, arsenic, cadmium

Question 5

What is the role of lead in environmental pathology?

Answer 5

mostly occupational
tons of effects, ill-defined cut-offs
mostly stored in bones and teeth
interferes w heme production to cause anemia
headache, memory loss, lack of attention, low IQ, demyelination, ab pain, kidney dz

Question 6

What is the role of mercury in environmental pathology?

Answer 6

fish and dental amalgams

cerebral palsy, deafness, blindness, CNS defects in fetuses

Question 7

What is the role of arsenic in environmental pathology?

Answer 7

water, soil, wood, preservatives, herbicides
homicidal poisoning
GI, cardiac, CNS, skin damage

Question 8

What is the role of cadmium in environmental pathology?

Answer 8

batteries
in soil, water, plants
damages lungs, kidneys, bones

Question 9

What are the effects of tobacco?

Answer 9

irritates mucosa = bronchitis
recruits leukocytes (elastases) = emphysema
compounds risks of other exposures
increased atherosclerosis and MI, maternal risks

Question 10

What are important numbers to remember w ethanol?

Answer 10

> .3 = coma and death

chronic alcoholics = .7

Question 11

What are the various pathological effects of ethanol?

Answer 11

fatty liver due to NADH > NAD
cirrhosis - hepatocyte death and regeneration
portal HTN –> varices
nutritional def (B12, thiamine, calories)
heart, pancreas, fetus
increased cancers
acute respiratory depression

Question 12

What are the pathological effects of aspirin?

Answer 12

respiratory alkalosis then metabolic acidosis
chronic use –> headache, dizziness, tinnitus, vomiting, diarrhea, gastric ulcers, bleeding, nephropothy
may lead to coma and death

Question 13

What are the pathological cardiovascular effects of cocaine?

Answer 13

tachy, HTN, vascoconstriction-hemorrhagic stroke
myocardial ischemia-infarction due to constriction and hypercoagulation
arrhythmias
not dose dependent

Question 14

What are the pathological CNS effects of cocaine?

Answer 14

hyperpyrexia and seizures

Question 15

What are the pathological fetal effects of cocaine?

Answer 15

fetal hypoxia, abortion
placental abruption
focal neurologic impairment

Question 16

What are the pathological effects associated w chronic use of cocaine?

Answer 16

nasal septum perfs in snorters
DCM
COPD-like effects in smokers

Question 17

How does heroin work?

Answer 17

acts on mu opioid receptors

stops GABA, stops reuptake of dopamine, stimulates reward centers

Question 18

What are the pathological effects associated w heroin?

Answer 18

sudden death - depressed respirations, arrhythmia, pulmonary edema
pulm dz - edema, foreign body granulomata, septic emboli, lung abscesses
infections inc skin
renal injury - amyloidosis and focal glomerulosclerosis

Question 19

What does clinical severity of burns depend upon?

Answer 19

depth - partial means basal layer okay and can regenerate, full means opposite
% BSA
inhalation of hot or toxic fumes - damages airways and lungs, poisons

Question 20

What are the different manifestations of hyperthermia?

Answer 20

heat cramps - loss of electrolytes via sweat w cramping muscles, can maintain core body temp
heat exhaustion - sudden collapse due to hypovolumia due to water loss, quick restoration
heat stroke - ambient high temps, sweating ceases, core body temp rises, peripheral pooling w myonecrosis, arrhythmia, DIC
malignant hyperthermia

Question 21

What are the features of hypothermia as environmental pathology?

Answer 21

homeless alcoholics
intra and extracellular water freezes - increases ion concentrations, blood viscosity, vascular permeability, edema
only evident after rewarming

Question 22

What is important to know about rewarming?

Answer 22

no one dead until warm and dead, especially children
functions halted w hypothermia can be regained after warming w/o permanent damage
some trauma pts treated w induced hypothermia

Question 23

What are the types of electrical injury?

Answer 23

burns, v fib or cardiac/respiratory electrical impulse disruption
extent depends on amps and path w/i body

Question 24

How does low voltage electricity cause injury?

Answer 24

120-220 V
low resistance (wet skin) can cause v fib
prolonged current flow causes burns at contact and to internal organs
muscle tetany prolongs contact-apshyxia

Question 25

How does high voltage electricity cause injury?

Answer 25

higher current stuns respiratory centers and causes burns

usually blown away from source –> short contact

Question 26

What are the factors that can affect the pathological effects of ionizing radiation?

Answer 26

rate of delivery - time to repair b/w doses
field size - keep small, use shields
proliferation rate of target - faster turnover, more sensitive
hypoxia - center of tumors w no blood flow, no damage
vascular damage - sensitive endothelium leads to leakage
CNS effects due to vascular damage not direct damage to neurons

Question 27

What is total body radiation?

Answer 27

from atomic bomb, nuclear power plant accident, etc

even low doses devastating

Question 28

What are the clinical manifestations of total body radiation?

Answer 28

acute radiation syndrome = N/V, fatigue
1-5 Gy = hematopoietic form
5-50 Gy = GI form - toxemia, death in 8-9 days
over 50 Gy = cerebral form - death w/i hrs, max 3 days