Environmental Pathology Flashcards
What is the mechanism of lead induced anemia?
-lead is found in air, soil, water, food, house dust, batteries, old paints, and gasoline
-85% of lead is taken up by bone and developing teeth
-lead competes with Calcium and interferes with remodeling
LEAD ALSO BLOCKS OR HINDERS THE INCORPORATION OF IRON INTO HEMOGLOBIN = anemia
What factors affect the clinical significance of thermal burns?
% body surface area (THE RULE OF 9's) *Head and Neck = 9% *Trunk Front = 18% *Trunk Back = 18% *Arms = 9% each *Hands= 1% each *Legs = 18% each *Perineum = 1 % [IF MORE THAN 50% BSA IS INVOLVED= grave prognosis] [IF MORE THAN 20% BSA IS INVOLVED= shock, infections, and hypermetabolic state]
What are the major cellular effects of radiation injury?
- Direct Damage to DNA
2. Indirect Damage: free radical production damages membranes, nucleic acids, and enzymes
What is the difference between marasmus and kwashiorkor?
Marasmus:
- deficient CALORIE intake
- break down proteins/amino acids for energy
- depletion of skeletal muscle and subcutaneous fat
- EMACIATED appearance of extremeties
- head looks too large for the body
- normal albumin
- T cell defects (Thrush is common infection)
- drop in body temp
Kwashiorkor:
- PROTEIN deficiency is greater than reduction in calories
- depletion of visceral protein compartments
- low albumin and generalized EDEMA
- skin/hair color changes
both: vitamin deficiencies, immune defects, growth retardation
What are the clinical signs of Vitamin A deficiency?
- impaired night vision (earliest sign)
- impaired immunity
- squamous metaplasia of respiratory and urinary tracts (infections and stones)
- dry eyes leading to corneal damage (later sign)
What are the clinical signs of Vitamin C deficiency?
- Scurvy:
- elderly, alcoholics, those with erratic eating habits, hemodialysis patients, infants fed non-fortified formula
- impaired collagen synthesis
- hemorrhages are common in skin and gingiva
- bleeding behind eyes, joints, and brain
- skeletal changes (cartilaginous overgrowth, bowing of long bones)
- depression of the sternum
- poor wound healing
- anemia is common
What are the clinical signs of Vitamin C toxicity? What is an excessive amount of Vitamin C?
> 2 grams per day
- fun fact: there are 51 mg in an orange*
- large doses causes enhanced iron absorption which could create iron overload
- high vitamin C will acidify urine and increase the risk for stones
- sudden change from high to low vitamin C could results in “rebound scurvy” which causes precipitation due to enhanced clearance mechanisms
What are the clinical signs of Vitamin A toxicity? What is an excessive amount of Vitamin A? Where do you get Vitamin A?
> 25,000 IU per day
= yellow/green leafy vegetables, liver, fish, EGGS, milk and butter
-usually toxicity is from supplement use
-acute toxicity: nausea, vomiting, irritability, headache, blurred vision
-chronic toxicity: anorexia, hair loss, dry skin, pruritis, dry mucous membranes, fissured lips, fatigue, weight loss, bone and joint pain
What are the four regulatory agencies for environmental hazards?
- EPA
- FDA
- OSHA
- Consumer Product Safety Commission
Injuries from _______ agents occur by inhalation, ingestion, injection, or absorption.
chemical
Children account for ____% of chemical injuries.
60
What are the factors that affect chemical injuries?
"CLADME" Concentration Liberation Absorption Distribution Metabolism Excretion
True or False: US work-related injuries occur twice as often as home injuries and has an annual cost of $500,000.
False
work injuries do occur twice as often
cost to the US is $25 BILLION annually!!!!!
True or False: Of the estimated 2 million hazardous exposures each year in the U.S., 90% are unintentional.
True
Oral intake accounts for ____% of exposures.
73
Children less than 6 years old account for ____% of exposures.
61
What are the most frequent agents of chemical exposure?
household items (cleaning agents, cosmetics, analgesics, plants, etc)
Anaphylaxis can occur with any medication but is most often associated with ______.
antibiotics (penicillin is the classic)
What are three common Adverse Drug Reactions (ADRs)?
- Aspirin
- Acetaminophen
- Exogenous estrogen/Oral contraceptives
- minor ADR = rash, GI upset
- major ADR = anaphylaxis, clots, anemia, arrythmias
True or False: ADRs are common.
True, adverse drug reactions account for 2%
Until 2002, exogenous estrogens were widely used for what reason? What does the recent data indicate?
Hormone Replacement Therapy for menopausal symptoms and osteoporosis prevention
-long term use is associated with elevated risk of breast cancer, strokes, and clots
What can been seen on x-rays and the gingival sulcus area in a patient exposed to high levels of lead?
“Lead Lines”
Wristdrop and Footdrop are associated with neural and sensory deficits from excess _____.
lead exposure
What is the threshold blood level of concern for lead?
greater than 45 micrograms/dL
True or False: Lead toxicity could take years to develop.
True
What kind of therapy is indicated when lead levels reach more than 45 micrograms?
Chelation therapy to bind the lead….however, there is no full recovery (kidney damage, GI tract damage)
What are the general classes of “drugs of abuse”?
- sedative-hypnotics (alcohol, benzo)
- CNS stimulants (cocaine)
- opioids (heroin, morphine, codeine)
- Cannabinoids (marijuana)
- Hallucinogens (LSD, ketamine)
- Inhalants (glue, paint thinner, gasoline)
- Nonprescription Drugs (atropine, antihistamines)
What are club drugs?
a collective term for substances that have become popular in dance clubs, bars, and raves. There are a variety of drugs including ecstasy, Meth, LSD, and Rohypnol (roofies)
What is a side effect of MDMA (ecstasy)?
bruxism
*many deal with the potential for fracturing teeth in a rave by using a pacifer (reportedly storing another hit)
Abrasion, contusion, and laceration are examples of _____ injuries.
mechanical
What is a laceration?
a tear in tissue, usually with irregular edges
What is a contusion?
a wound caused by a blunt object, doesn’t break the skin but could damage blood vessels (bruise)
____ is a wound caused by scraping or rubbing that leads to removal of superficial layers of skin.
abrasion
ADR’s are highly related to ______ which is seen most clearly with _______ drugs.
potency
anti-cancer drugs
In what temperature range does the body operate?
31 to 41 degrees celsius
90 to 105 degrees F
_____ cause more than 5000 deaths per year in the US.
Hyperthermia (burns)
A burn that covers a surface area percentage greater than _____ will put the patient at high risk for sudden death due to fluid/electrolyte loss and infection.
50
According to the “rule of 9’s” what bsa percentage does the trunk account for?
18% front
18% back
The bsa for each arm is ____ % and each leg is ____%.
arm 9%
leg 18%
The hands and the perineum each account for ___% of bsa.
1 % each
What are the factors that affect clinical significance of burns?
- percentage of BSA
- depth of burn (full vs partial thickness)
- Potential for internal injury from fumes or gasses
- Age of the patient
- How quickly and efficiently the burn is treated
With more than 20-30% total bsa involvement, a burn can cause massive fluid shifts that lead to _______.
hypovolemic shock
What are two organisms that frequently cause infections in burn sites?
pseudomonas and candida
True or False: Any part of the respiratory tract can be damaged through noxious fume inhalation (CO, cyanide, steam).
True, URT or LRT can be affected
The most common cause of ARDS is sepsis; however, it can also result from breathing in high concentrations of smoke or chemical fumes. What is ARDS?
Acute respiratory distress syndrome (ARDS)
- occurs when fluid builds up in the tiny, elastic air sacs (alveoli) in your lungs.
- More fluid in your lungs = less oxygen
- Organs are deprived of the O2 they need to function.
______: often related to exercise with loss of fluids and electrolytes
heat cramps
What is heat exhaustion?
shock due to rapid hypovolemia
True or False: Recovery from heat exhaustion is usually spontaneous.
True
Heat Stroke occurs with temperatures above ______ that cause peripheral ______, confusion, ischemia, muscle necrosis, and ______.
above 40 degrees Celsius
vasodilation
DIC
True or False: Heat stroke has a low mortality rate.
False!
What causes hypothermia?
abnormally low core temperature
*Facilitated by: high humidity, wet clothes, vasodilation (alcohol)
What are the temperature ranges associated with mild, moderate, and severe hypothermia?
mild: 32-35 degrees C (89-95 F)
mod: 28-32 degrees C (82-89 F)
severe: less than 28 C (less than 82 F)
What are the local and systemic reactions associated with hypothermia?
LOCAL: freezing of cells/tissues due to crystallization of water, vasoconstriction and circulatory changes (gangrene), and edema (fibrosis/atrophy when long term)
SYSTEMIC: disorientation and “paradoxical undressing”
What are the common sources of radiation injuries?
cosmic rays UV rays elements from Earth's crust (radon) medical sources industrial sources weapons nuclear power plants
____ and _____ are two forms of electromagnetic waves that cause radiation injury.
x ray
gamma ray
True or False: Low energy neutrons and charged particles called alpha and beta particles can cause radiation injury.
False, alpha and beta= HIGH energy
Radiation interacts with atoms and molecules by _____ and ______.
excitation
ionization
What are the mechanisms of radiation injury on biological systems?
- target effects: direct hit on DNA, causes mutation
2. indirect effects: free radical production, damage to membranes, nucleic acids, and enzymes
True or False: Radiation injuries may be reversed.
True,
reversible OR may lead to cell death and fibrosis
Radiation injuries cause harm to DNA, nucleic acid, enzymes. It also affects the ______ which leads to swelling, changes in membranes, mitochondria, and endoplasmic reticulum.
cytoplasm
What cell types are extremely susceptible to radiation damage?
hematopoietic and lymphoid
Describe the skin changes (over time) associated with radiation exposure.
2-3 days: erythema/redness
2-3 weeks: edema
4-6 weeks: blistering/desquamation
months-year: atrophy, fibrosis, neoplasia
Lymphocytes that are exposed to radiation will decrease within ______ and rebound within _____.
hours
weeks to months
Granulocytes exposed to radiation will decrease over _______ and rebound in ______. What is important about this time frame?
1-2 weeks decrease
2-3 months rebound
-during this time patients are extremely susceptible to infections!
True or False: Lymph nodes and spleen will increase in size due to radiation exposure.
False, they will shrink
True or False: The gonads are particularly sensitive to radiation injury and could become sterile.
True
How is the GI tract affected by radiation?
very sensitive
- ulcers
- strictures
- possible carcinomas occur later
Blood vessels exposed to radiation will first have ______ injury and then later may become _______ and narrow.
endothelial
fibrotic
What is the lethal range of total body radiation?
range begins at 2 Sieverts.
at 7 Sv, death is certain without treatment
What are the three fatal acute radiation syndromes?
- Hematopoietic
- Gastrointestinal
- Cerebral
Which radiation syndrome occurs with 2-10 sieverts and results in sepsis, GI symptoms, bleeding, decreased white blood cells, and death within 2-6 weeks?
hematopoietic
Which radiation syndrome occurs with 10-20 sievert exposure?
gastrointestinal
bloody diarrhea, dehydration, shock, death in 5-14 days
Which radiation syndrome occurs with more than 50 sievert exposure?
cerebral
drowsiness, followed by seizures, coma, and death in 1-4 hours
What is an adequate diet?
One that provides:
- sufficient Carbs, proteins, and fats for metabolic needs
- essential amino and fatty acids for synthesis of proteins and lipids
- vitamins, minerals, coenzymes, or hormones
What is primary malnutrition?
diet is deficient in one or more compartments
What is secondary malnutrition?
supply is adequate, but there may be a problem with absorption, storage, utilization, losses, or drug effects
What are the two major disorders associated with Protein-Energy Malnutrition?
Kwashiorkor
Marasmus
What are the two protein compartments within the body?
- Somatic (skeletal muscles, assessed by skinfold thickness)
- Visceral (mainly the liver, assessed by measuring serum proteins-albumin, transferrin)
Marasmus is a deficiency of _______. How does the body maintain its energy supply in this case?
calorie intake
- catabolism of muscle mass/proteins and subcutaneous fat
- results in growth retardation and depletion of somatic protein compartment
______ is a common finding and an indicator of immune system deficits. Also, the body temperature may be decreased and the pulse slowed.
Thrush
In kwashiorkor, the most common PEM found in Africa, there is a deficiency in _______.
PROTEIN more than in total calories
True or False: Marasmus is more severe than Kwashiorkor.
False, Kwashiorkor is more severe
Which protein compartment is depleted in each of the PEMs?
Kwashiorkor: depletes the VISCERAL compartment
Marsmus: depletes the SOMATIC compartment
With Kwashiorkor, there is a significant decrease in _______ which causes a loss of vascular _____ pressure and generalized fluid retention/edema.
albumin
oncotic
What are the changes that present in children with kwashiorkor?
hyperpigmentation desquamation and hypopigmentation (Flaky Paint) hair changes fatty liver vitamin and immune dysfunction
What are the fat soluble vitamins?
A
D
E
K
-absorption of fat-soluble vitamins depends on healthy intestinal mucosa and is influenced by diseases such as Crohn’s and alcoholic liver disease
-deficiencies develop slowly due to easy storage
Over 90% of vitamin A is stored in the _______.
liver
stored for 6-12 months
When needed, how does the body move vitamin A?
vitamin A has three active forms (retinol, retinal, retinoic acid)
- it is stored in the liver
- when needed, it is released by the liver and bound to a carrier protein (RETINOL-BINDING PROTEIN)
What are the three functions of Vitamin A?
- maintain normal vision in reduced light
- augments differentiation of specialized epithelial cells (mucus secreting)
- enhances immunity to infections, especially in kids
What are the three functions of Vitamin C?
- formation and stabilization of collagen (hydroxylation of proline and lysine)
- conversion of tyrosine to catecholamines
- role as an antioxidant
What is an early sign of Vitamin A deficiency?
impaired night vision
How is the respiratory and urinary tract affected by Vitamin A deficiency?
squamous metaplasia = increases risk for infections and stones
