Ch10: Environmental Pathology Flashcards
1
Q
What are three major determinants of our health?
A
- Air we breath
- Food and water we consume
- Exposure to toxic agents
2
Q
What is an environmental disease?
A
Condition caused by exposure to chemical or physical agents in a person’s environment
3
Q
What is overall fatality rate of occupational injuries?
A
4.8 per 100,000 workers
4
Q
Who set the standard for reporting health information?
A
Global Burden of Disease
5
Q
What is the GBD statistic for assessing premature mortality and disease morbidity?
A
DALY (Disability adjusted life year)
6
Q
What is the DALY statistic?
A
adds the years of life lost to premature mortality with the years lived with illness and disability.
7
Q
What is said to increase due to human activity in regards to climate change?
A
- CO2
- Methane
- Ozone
8
Q
Causes of increased CO2? (2)
A
- Combustion of hydrocarbons in automobiles and energy plants
- Deforestation
9
Q
Problems with human health in regard to climate change? (4)
A
- CV, Cerebrovascular, Respiratory disease
- Gastroenteritis and infectious disease
- Vector-borne infectious diseases
- Malnutrition
10
Q
What is the definition of poison?
A
A dose that causes harmful effects instead of helpful
11
Q
How many pounds of carinogenic toxic chemicals are released per year in the US?
A
4 billion pounds
12
Q
What 4 agencies determine exposure limits?
A
EPA
FDA
OSHA
CPSC
13
Q
The EPA regulates what?
A
Exposure to peticides, toxic chemicals, water and air pollutants
14
Q
The FDA regulates what?
A
drugs, medical devices, food additives, and
cosmetics
15
Q
What does OSHA mandate?
A
employers provide safe working conditions for
employees
16
Q
What does CPSC regulate?
A
other products sold for use in homes, schools, or
recreation
17
Q
What are xenobiotics?
A
Exogenous chemicals in the air, water, food
and soil that may be absorbed into the body
through inhalation, ingestion, and skin contact
18
Q
Where do xenobiotics act? (2)
A
Site of entry
Transported to distant tissues by BV’s
19
Q
What xenobiotics are metabolized to form inactive water-soluble products or activated to form toxic metabolites? 2
A
Solvents
Lipophilic drugs
20
Q
Most important catalyst of phase I reactions is what?
A
Cytochrome p450 system
21
Q
Carbon tetrachloride is metabolized to what in the liver?
A
Toxic trichloromethyl free radical
22
Q
Benzo-alpha-prene is metabolized to what?
A
DNA-binding metabolite carcinogen
23
Q
Xenobiotics are typically eliminated how?
A
Phase I reaction
Phase II reaction to soluble metabolite
Eliminated from body
24
Q
What does Radon cause?
A
Lung disease and cancer
25
EPA has limits for what 6 pollutants?
1. Ozone
2. Nitrogen oxides
3. Sulfur dioxide
4. Particulates
5. CO
6. Lead
26
Smog is what?
Smoke and fog
27
What leads to formation of ozone layer?
Interaction of UV radiation and oxygen in the stratosphere
28
Why is the ozone layer good?
Absorbs the most dangerous UV from sun
29
What causes ozone layer loss?
Halocarbons like CFP's
30
Toxicity of ozone is due to what?
Production of free radicals that injury lung epithelial cells and Type I alveolar cells
31
How does ozone cause release of inflammatory mediators?
Oxidizes lipids to H2O2 which acts as irritant
32
Overall effect of ozone on lungs? (3)
1. Increase epithelial permeability
2. Increased reactivity of airways
3. Decreased ciliary clearance
33
Nitrogen dioxide does what in the airway?
Dissolves in water to form nitric acid which damages airway epithelium
34
Sulfur dioxide is produced by who? 2
Power plants burning coal and oil
| Byproduct of mills
35
SO2 is absorbed in airways where it releases what? (3)
| Effect of this?
H+, HSO- (bisulfite), SO3 (sulfite)
| Local irritation
36
Particulate matter like soot is most hazardous at what size?
Ultrafine (<10 um)
37
What is effect of ultrafine soot in lungs?
Phagocytosed by macrophages which causes release of inflammatory mediators that damage lungs
38
What is anthracosis?
Black pigment in lungs
39
3 main effects of soot in lungs?
1. Cytokine release systemically
2. Increased blood viscosity
3. Autonomic changes affecting the heart
40
Carbon monoxide has what four characteristics?
1. nonirritating
2. colorless
3. tasteless
4. Odorless
41
What produces CO?
Incomplete oxidation of carbon materials
42
Greatest danger of CO toxicity is when?
Working in confined environments with high exposure (in a garage will kill in 5 minutes)
43
Carbon monoxide effects? 2
1. CNS depressant
| 2. Binds to hemoglobin causing loss of oxygen
44
Severe hypoxia occurs when with CO?
20-30% saturation
45
Death and loss of consciousness occur when with CO?
60-70 percent saturation
46
Indoor air pollution includes? (4)
1. tobacco smoke
2. CO
3. NO2
4. Wood smoke (NO's, soot, hydrocarbons)
47
Formaldehyde is found in what especially?
New carpet
48
Radon is a decay product of what?
Uranium and is found in soil
49
Asbestos fibers are found where?
Houses built before 1970
50
Bioareosols are used for what?
Aerosolization of bacteria
51
What is the famous bioaerosol exposure?
Legionella pneumophilia
52
Lead exposure occurs through what? 3
Air, food and water
53
Most absorbed lead goes where?
What does it compete with?
How is it seen radiographically?
Bone and teeth
Calcium
Lead lines along growth plates
54
Is acute poisoning of lead common?
No.
55
Acute Lead poisoning is seen with what main symptoms? 2
Neurologic symptoms
| GI symptoms
56
Why are children affected more than adults by lead?
1. Absorb 50% of ingested lead compared to adults' 15%
| 2. More permeable blood brain barrier
57
Which nervous system is affected more in children?
| More in adults?
```
Children = CNS
Adults = PNS
```
58
How does lead present in terms of blood?
Microcytic anemia with coarse basophilic stippling
59
When will you see the microcytic anemia with coarse basophilic stippling in lead toxic patients?
At 40 ug/ml
60
Arsenic intereferes with what?
Cellular longevity by interfering with oxidative phosphorylation
61
Signs and symptoms of acute arsenic poisoning?
1. HA
2. Confusion
3. Convulsion
4. Diarrhea
5. Vomiting
6. Neuropathies
62
Long term exposure to arsenic leads to what?
Night blindness due to Vitamin A deficiency
63
3 cancers caused by long term arsenic exposure?
1. Cutaneous basal cells
2. Squamous cell
3. Lung carcinomas
64
Cadmium is generated where? 2
Mining
| Cadmium nickel batteries
65
Toxicities of cadmium include what? 4
1. Obstructive Lung disease
2. End stage renal disease
3. Skeletal problems
4. Lung carcinomas
66
Three main forms of mercurcy?
1. Elemental
2. Inorganic: Mercury chloride
3. Organic: Methyl mercury
67
Modern sources of mercury? (4)
1. Contaminated sea food
2. Dental
3. Gold mining
4. industry
68
Clinical manifestation of mercury? 4
1. Nervous system: CNS malfunction and peripheral neuropathies
2. Kidney injury
3. Tremors/bizarre behavior
4. Gingitivitis
69
What is methyl mercury particularly toxic to?
Developing CNS
70
Chronic exposure of mining and industrial chromium and nickel has what effect?
Increased nasal and lung carcinomas
71
Cause of heart disease? (4)
1. CO
2. Lead
3. Solvents
4. Cadmium
72
Cause of nasal cancer? 2
1. Isopropyl alcohol
| 2. Wood dust
73
Cause of lung cancer? 7
1. Radon
2. Asbestos
3. Nickel
4. Arsenic
5. Chromium
6. Mustard gas
7. Uranium
74
Cause of COPD? 2
1. Dust
| 2. Cadmium
75
Cause of respiratory irritation? 3
1. ammonia
2. sulfur oxide
3. formaldehyde
76
Cause of fibrosis in respiratory?
1. Asbestos
77
Organic solvents are readily obsorbed where? 2
Skin
Lungs
GI
78
Organic solvent acute exposure can lead to what?
CNS depression/Coma
79
Huffing involves inhalation of what?
Organic solvents
80
Benzene is metabolized by what?
| What do its metabolites cause? (3)
Cytochrome p450
1. Bone marrow toxicity
2. Leukemia
3. Aplastic anemia
81
Polycyclic aromatic hydrocarbons are composed of what?
Aromatic rings in a flat plane
82
PAH's are found in what? 4
Foundries
Tars
Soot
Tobacco smoke
83
What are PAH's considered?
Most potent chemical carcinogens
84
PAH's are so potent why?
Very common and highly carcinogenic
85
Industrial exposure to PAH's is linked to what? 2
1. Bladder carcinoma
| 2. Lung carcinoma
86
Organochlorines are lipophilic products that can resist what?
Degradation
87
Organochlorines have what type of activity?
Anti-estrogenic and Anti-Androgenic leading to decreased fertility rates
88
What are most organochlorines used for?
Pesticides
89
Non-pesticide organochlorines are known to cause what? 4
1. Chloracne
2. CNS probs
3. Hepatic probs
4. Induce cytochromes
90
What is chloracne?
Hyperpigmentation and hyperkeratosis of face and ear
91
Vinyl chloride is used to produce what?
Polymer polyvinyl chloride (PVC)
92
What will vinylchloride cause?
Anglosarcoma of liver
93
Mineral dust inhalation causes what?
| 4 Examples?
Chronic, non-neoplastic lung disease "Pneumoconioses"
1. Black lung
2. Silicosis
3. Asbestosis
4. Berylliosis
94
What is the most preventable cause of human death?
Smoking tobacco
95
How many people die due to tobacco smoke in US a year?
440,000
96
What are the causes of death in smokers? (10)
1. Lung cancer
2. Esophageal cancer
3. Bladder cancer
4. Oral cavity/URT cancer
5. Pancreatic cancer
6. Athersclerosis
7. CAD
8. Emphysema
9. COPD
10. Respiratory infections
97
What is the number 1 cancer killer of men and women?
Lung cancer
98
What % of lung cancers is tobacco responsible for?
90%
99
Where does lung cancer rate in terms of cancer incidence in men and women?
#2
100
What are two ways to reduce your cigarette cancer risk?
1. Delay onset of smoking habits
| 2. Quitting
101
Is nicotine carcinogenic?
No, just a physical addiction
102
What does nicotine do?
Binds to receptors in brain causing release of ACh that increases HR and BP, and contractility and output
103
How are the inhaled agents of cigarette smoke harmful? (3)
1. Act on mucus membranes
2. Swallowed in saliva
3. Absorbed in blood stream to act on distant organs
104
How many components of tobacco are carcinogens?
60
105
Tobacco smoke increases risk of atherosclerosis how?
1. In addition to HT and hypercholesterolemia
2. Increases platelet adhesion and aggregation --> Vascular thromboses --> MI's and CVA's
3. Increase hypoxia --> increase arrhthmias and MI's
106
Effect of tobacco on respiratory? 2
1. Allows for RT infections by destroying cilia
| 2. Irritation of respiratory epithelium leading to COPD
107
Effect of tobacco on GI?
Peptic ulcer disease
108
Effects of tobacco on fetus?
1. Fetal hypoxia
2. Low birth weight
3. premature
4. increased spontaneous abortion
5. Complications at delivery mainly with placenta
109
Effect of smoking on kids? (3)
1. Infections
2. Asthma
3. SIDS
110
Differences between tobacco chewing and smoking? 4
1. Lungs spared
2. Oral cavity irritation
3. Increased caries, gingivitis, loss of feeth
4. stains tooth enamel
111
What are the numbers used to compare wine, beer, and liquor alcohol contents?
5 ounces of 24 proof wine
12 ounces of 10 proof beer
1.5 ounces of 80 proof liquor
112
Can one die from acute alcohol intake?
Yes
113
How is ethanol absorbed in GI?
Unaltered.
114
Oxidation of ethanol in metabolism produces what?
Toxic agents like acetaldehyde
115
How is ethanol oxidized to acetaldehyde? 3
1. In peroxisome by catalase
2. In cytosol by ADH
3. In microsomes by CYP2E1
116
How is acealdehyde converted to acetic acid?
ALDH in mitochondria
117
What is the genetic polymorphism in alcohol dehydrogenase?
50% of Asians have increased activity due to point mutation so that they convert more than normal ethanol to acealdehyde leading to flushing, nausea, and tachycardia
118
Who has higher levels of gastric alcohol dehydrogenase activity?
What does this mean?
Men
Women develop higher blood alcohol levels than men after same amount of ethanol
119
Acute ethanol toxicity includes? (4)
1. CNS depressant
2. Ulceration
3. Steatosis
4. Acetaldehyde effects --> Esophageal and oral cancers
120
Chronic ethanol toxicity includes?
1. Liver (steatosis, hepatitis, cirrhosis, liver carcinoma)
2. Nervous system: Wernicke-Korsakoff, PN's
3. GI tract: Ulcers, esophageal varices, malnutrition
4. Pancreas: Pancreatitis
5. Cardiac: cardiomyopathy, HT
6. Cancers: Oral, esophageal, liver
7. Pregnancy/Fetus: FAS
121
What is most common cause of preventable congenital retardation in US?
Rate of it?
FAS (1-5 per 1000 births)
122
Ethylene glycol is metabolized by what?
| To produce what?
Alcohol dehydrogenase
Glycolic acid and oxalate
123
Glycolic acid is responsible for what? 92)
1. CNS probs
| 2. Anion gap acidosis
124
Oxalate does what?
Binds calcium to form calcium oxalate that deposits in kidneys.
125
Methanol is metabolized by what?
| To form what?
Alcohol dehydrogenase
Formaldehyde and Formic acid
126
Methanol metabolites cause what? (4)
1. Ocular toxicity (blurred vision and blindness)
2. Vomiting
3. Dizziness
4. Elevated anion gap acidosis
127
What do you give to patients with ethylene glycol and methanol overdose? 2
Ethanol or fomepizole to compete for ADH enzyme spots.
| Dialysis
128
Elevated anion gap acidosis is do to what? 9
```
MUDPLIERS
Methanol
Uremia
Diabetic ketoacidosis
Paraldehyde/Phenformin
Isopropyl alcohol/Isoniazid
Lactic acidosis
Ethylene glycol/Ethanol
Rhabdomyolysis
Salicylates
```
129
How many women use hormonal contraception?
| What % of reproductive women use reversible methods?
greater than 100 million
64%
130
What population uses oral birth control pills the most?
Teenagers and Twentys
Never married
College degree
131
Adverse effects of OBC's include?
1. Thromboembolism
2. CV disease
3. Liver tumors
132
OBC's thromboembolism increases DVT risk how much?
| What factors increase risk? (5)
3 fold
```
Factor V mutation
Prothrombin mutation
Older than 35
Smoking
Combined estrogen/progestin OBC's
```
133
Increased thrombotic risk in OBC's seems due to what?
Acute phase response that increases CRP and coagulation factors (7, 9, 10, 12, 13) and a reduction in anticoagulants (protein S and anti-thrombin III)
134
Explain OBC and CV risk? 2
Being older than 35
| Smoker of all ages
135
What type of liver tumors with OBC's?
Benign hepatic adenoma
136
HRT has what risks? 3
1. Endometrial hyperplasia/carcinoma
2. Increased breast carcinoma risk
3. Venous thrombosis and PE (Especially first 2 years of use and if you have other risk factors)
137
Anabolic steroids can have what effects? 7
1. Stunted growth
2. Acne, gynecomastia, and testicular atrophy in males
3. Acne, hirsutism, and menstrual changes in females
4. Rage
5. CAD
6. Hepatic cholestasis
7. Increased prostate carcinoma
138
What is the most commonly used analgesic in the US?
Acetaminophen
139
What percentage of acute liver failure disease is acetaminophen caused?
Half
140
At therapeutic doses what happens in metabolism of acetaminophen?
1. 95% phase II detox in liver and excreted in urine
| 2. 5% cytochromes convert it to NAPQI which is a reactive metabolite that will harm the liver.
141
What is the therapeutic window?
The window where the therapeutic dose doesn't become toxic
142
Acetaminophen has a small or large therapeutic window?
Large
143
Overdoses of acetaminophen cause what?
GI problems and liver problems
144
What type of therapy is used to reverse acetaminophen toxicity?
Mucomyst (acetylcysteine)
145
What location in the liver has the lowest O2 concentration?
Around central vein
146
Where does acetaminophen cause damage in the liver?
Around central vein
147
Aspirin has what three effects?
1. Irreversibly inhibits COX-1
2. Modifies activity of COX-2
3. Blocks production of thromboxane A2
148
Acute overdose consequences of aspirin are morphologic or metabolic?
Metabolic
149
What happens in an acute aspirin overdose?
1. Respiratory alkalosis
2. Metabolic acidosis
3. Fatal
150
Acidosis in aspirin overdose allows what?
Formation of non-ionized salicylates which go to brain and cause nausea/coma
151
Chronic toxicity of aspirin (salicylism) involves what dose?
3+ grams daily for long periods
152
Symptoms of aspirin chronic toxcitiy?
1. Headaches and tinnitis
2. GI problems
3. Coma
4. Abnormal bleeding.
5. Neuropathy
153
Aspirin and tylenol together is hard on what?
Renal papillae
154
Crystallization of pure cocaine yields what?
Crack cocaine
155
What does cocaine produce?
Euphoria and stimulation
156
Does cocaine have physical dependence?
No, but severe psychological
157
Cocaine blocks reuptake of what? (3)
1. Dopamine
2. Serotonin
3. Catecholamines
158
Cocaine also prolongs what?
| And blocks what other reuptake?
Dopaminergic effects in brain pleasure areas
Epinephrine and norepinephrine
159
Clinical clues for possible cocaine abuse?
1. tachycardia/HT
2. CAD
3. Nasal septum problem
4. needle tracts
5. Seizures
160
What is heroin?
Opioid narcotic from opium or synthesized from morphine
161
What is used in treatment of heroine addiction?
| Has what problem?
Methadone
| Killing people in overdose
162
IV heroin and other opiates cause what?
1. CNS depression: hypoventilation (respiratory acidosis), GI issues, seizures
2. Pulmonary injury: Edema, emboli, granulomas
3. Infections: Skin, heart valves, liver, and lungs
163
What are two main infections due to heroin?
1. Staph aureus on tricuspid valve
| 2. Viral hepatitis
164
Evidence of heroin addiction? (4)
1. Narcotic abstinence syndrome
2. Infections
3. Renal disease: Focal segmental glomerulosclerosis
4. Cutaneous scars, hyperpigmentation of skin over veins and thrombosed veins.
165
Two types of amphetamines?
Methamphetamines
| MDMA
166
Methamphetamine acts how?
Releases dopamine --> Inhibits presynaptic neurotransmission at corticostriatal synapses, slowing glutamate release --> Euphoria with a crash
167
How does MDMA/ecstasy work?
Euphoria and hallucinations due to altered serotonin levels in CNS
168
Marijuana is from what?
Cannabis sativa plant with high levels of THC
169
Marijuana has what effects?
1. Distorts sensory and motor
2. Euphoria, paranoia, bad judgment
3. Increased appetite and dry mouth
4. Irritant and carcinogen
170
Cycad flour contains what?
Toxin cycasin
171
How do you avoid the toxins in cycad flour?
Cut seeds and soak them to get the toxin out.
172
Cycasin poison has what effect?
Degenerative neurologic disorder
173
Aflatoxins are natural toxins produced by what?
Aspergillus?
174
Where is aspergillus found?
In stored grains
175
Aflatoxin effect on humans?
1. Toxic to liver
| 2. Carcinogenic to liver
176
Unintentional injuries/trauma rank where in deaths of adolescents and adults under 44 y/old?
First
177
What percentage of unintentional injuries involve ethanol?
40%
178
Motor vehicle accidents caused by what?
1. Impact of vehicle on person
2. Ejection from vehicle
3. Trapped in vehicle
4. Alcohol use
179
What is an abrasion?
superficial epidermis is torn off by friction or
| force
180
Is there scarring in abrasion healing?
No, but risk of infection
181
What is a laceration?
irregular tear in the skin produced by tissue
| stretching due to blunt force
182
Lacerations are typically seen how? 2
1. bridging strands of fibrous tissue or
blood vessels across the wound
2. immediate margins are frequently hemorrhagic
and traumatized
183
Incisions are usually made by what?
Sharp cutting object
184
Describe margins and bridging in incisions?
Margins = clean
| No bridging
185
What is a stab wound?
depth of wound greater than length of
| wound
186
What is puncture wound?
deep penetrating wounds made by a
| long thing object such as a nail or ice pick
187
What is penetration wound?
open wound that enters and
| exists the body
188
What is a gun shot wound?
caused by bullets or pellets fired from a gun, can be penetrating if the bullet or pellets exit the body
189
What is a contusion?
blunt force that damages small vessels and causes extravasation of blood into tissues
190
What is a superficial burn?
(1st degree): Confined to
| epidermis
191
What is a partial thickness burn?
(2nd degree): Injury to the
dermis (at least the deeper portions of the dermal
appendages are spared to regenerate epithelium)
192
What is a full thickness burn?
Extends to subcutaneous
tissue (3rd degree) and may involve muscle (4th
degree)
193
What is destroyed in full thickness?
the epidermis and dermis
| and anesthesia due to nerve ending destruction
194
What will cause a burn to be fatal?
Any burn exceeding 50% of total BSA
195
What happens if burn is above 20% BSA?
Fluid shifts to interstitial compartments --> Hypovolemic shock
196
What causes the hypovolemic shock in a burn? 2
1. Increase in interstitial osmotic pressure
| 2. Neurogenic and mediator induced vascular permeability
197
Injury to airways and lungs in thermal injury may result from what? 2
1. Direct effect of heat
| 2. Inhalation of smoke
198
What is teh most common seconday infection in thermal injury?
What other two?
Pseudomonas aeruginosa
Candida and s. aureus
199
What causes heat cramps?
What is the hallmark
What is the mechanism?
Loss of electrolytes through sweating
Cramping of voluntary muscles during exercise is
the hallmark
Heat dissipating mechanisms able to maintain
normal core temp
200
What is the onset of heat exhaustion?
| Why does it occur?
Sudden collapse
failure of the cardiovascular system to
compensate for hypovolemia, secondary to water
depletion
201
What is heat stroke associated with? (2)
High ambient temperature
| High humidity
202
What fails in heat stroke?
Thermoregulatory mechanisms fail, sweating
ceases, and core body temp rises – multi-organ
dysfunction - death
203
What is the sign of heat stroke?
Rectal temp above 106 F
204
What is the mechanism of heat stroke?
Mechanism is peripheral vasodilation with marked
pooling of blood and a decreased effective
circulating volume
» Necrosis of skeletal and cardiac muscle -
rhabdomyolysis
205
Lowering of body temperature in systemic hypothermia is exacerbated by what? 3
1. high humidity
2. cold wet clothing
3. alcohol
206
When body gets to 90 degrees F, what happens? (3)
1. loss of consciousness
2. bradycardia
3. atrial fib
207
What do hypothermic patients do that seems strange?
Want to take clothes off despite freezing
208
What is frostnip?
cooling, usually of apical structures such as
| nose, cheeks and ears, from cold air exposure
209
What is chilblain?
exposure to damp, non-freezing
temperatures that causes a vasculitis with red, raised
lesions
210
What is immersion foot?
prolonged exposure
| to wet, cool conditions
211
What is frostbite?
Freezing of tissue
212
Which is the most severe form of peripheral cold injuries?
Frostbite can lead to ischemia, gangrene and amputation
213
Direct effects of hypothermia are mediated by what? 2
1. Physical disruption of organelles within the cells
| 2. High salt concentrations incident to the crystallization of the intra and extracellular water
214
Indirect effects of hypothermia result from what?
| What do they depend on? 2
Circulatory changes
1. Rate of temp drop
2. Duration of temp drop
215
Slow chilling induces what? (2)
| Leading to what?
1. vasoconstriction
2. increased permeability
edema
216
Rapid chilling induces what? (2)
| What happens upon temperature rising?
1. Vasoconstriction
2. Ischemic injury
Increased permeability with exudation
217
Electrical injury in the house can be serious when?
If there is low resistance like wet skin, can cause serious injury like ventricular fib
218
Current from high voltage sources are more likely to produce what? (2)
1. Paralysis of medullary centers
| 2. Extensive burns
219
What are two most important variables in electrical injury?
1. Resistance of tissue
| 2. Intensity of current
220
Tissue resistance to flow varies how with water content?
Inversely.
| Dry skin has greater resistance than wet
221
Thermal effects of electrical injury depends on what?
intensity of current
222
What is radiation?
energy that travels in the form of
| waves or high-speed particles
223
Two types of radiation?
Nonionizing
| Ionizing
224
Non-ionizing radiation is characterized by what? 3
longer wavelengths, lower
| frequencies and lower energy
225
Ionizing radiaiton can cause what?
Tissue heating
226
typical sources of non-ionizing radiation? 2
sunlight
| UV
227
Ionizing radiation is characterized by what?
Shorter wavelengths
Higher frequency
Higher energy
228
Ionizing radiation will disrupt what?
Metabolism.
229
Examples of ionizing radiation? (5)
1. X rays
2. gamma rays
3. high energy neutrons
4. Alpha particles
5. beta particles
230
Alpha particles induce what type of damage?
| What do they do poorly?
Heavy damage in a certain area
Penetrate poorly due to size
231
3 ways to measure ionizing radiation units?
1. Amount emitted by source
2. Amount absorbed
3. Effect of radiation
232
What is a Curie?
| It is an expression of what?
Amount of disintegration per second of a radionuclide.
Amount of radiation emitted
233
What is a Gray?
The energy absorbed by the target tissue per unit mass
234
What is a Sievert?
Unit of doses that depends on biologic effects of radiation
235
What areas of the body are most affected by ionizing radiation? 2
Why?
Bone marrow and GI
Rapidly dividing
236
What are the main determinants of biological effect of ionizing radiation?
1. Rate of delivery
2. Field size
3. Cell proliferation
4. Oxygen effects and hypoxia
5. Vascular damage
237
explain how rate of delivery impacts ionizing radiation effect?
Divided doses allow cells to repair some damage during exposures.
238
Which recover faster to radiation, normal cells or tumor cells?
Normal cells
239
Explain how size of field can have effect on ionizing radiation damage?
High doses at small shielded fields = okay
| Smaller doses to larger fields = bad
240
Explain how proliferation can have effect on ionizing radiation damage?
Damages DNA so rapidly dividing cells are vulnerable: Gonads, BM, lymph, mucosa of GI
241
Cells in what cell cycle stages are most susceptible to ionizing radiation damage?
G2 and M
242
What is the most important mechanism of radiation damage?
Production of ROS
243
Which is more sensitive to radiation injury, well vascularized or poorly vascularized tissues?
Well Vascularized (more O2)
244
Effect of radiation on BV's?
Sclerosis which impairs function
245
BV change to radiation?
Subintimal fibrosis with narrowing of lumen
246
Skin changes to radiation?
1. Atrophy of epidermis
| 2. Hyperkeratosis and hyper/hypopigmentation
247
How long can squamous and basal cell carcinomas occur after radiation exposure?
20 years
248
Heart changes due to radiation?
Fibrosis
249
Lung changes due to radiation?
Fibrosis
250
Kidney changes due to radiation? 2
1. Fibrosis
| 2. Hyalinizatin of glomeruli
251
GI, breast changes due to radiation?
Fibrosis
252
Ovary and testis changes due to radiation?
Suppression of meiosis --> infertility
