Environmental and Nutritional Diseases Flashcards
What is “personal environment?”
The stuff that we choose to expose ourselves to like smoking, alcohol, etc.
What is a xenobiotic?
An exogenous chemical in the environment that is absorbed by the body somehow (inhalation, ingestion, through skin, etc.).
Are most solvents and drugs lipophilic?
Yeah
Most chemicals are altered through a ____-step process.
two step process.
Describe the two phases of xenobiotic metabolism.
Phase 1: Hydrolysis, oxidation, or reduction produces a primary metabolite.
Phase 2: Conversion of the primary metabolite into H2O soluble compounds by gucuronidation, sulfation, methylation, or glutathione conjugation. Once compounds are H2O soluble, they can be excreted.
What is the most important enzyme system involved in drug metabolism?
CYP450
In which two ways can metabolism of drugs harm cells?
- Metabolism from an inactive compound into an active, harmful compound.
- ROS generated in the metabolic process.
What effect does grapefruit juice have on CYP3A4 in the intestine?
It inactivates it, increasing bioavailability.
The most common air pollutants are _______, which in combination with oxides and particulate matter forms smog, sulfur dioxide, acid aerosols, and particles of less than ___ μm in diameter.
ozone
less than 10 micrometers in diameter.
Describe the three toxic effects of ozone inhalation.
- Decreased lung function.
- Increased airway reactivity –> lung inflammation.
- Free radical production.
Describe the three toxic effects of nitrogen oxide inhalation.
- Decreased lung function.
- Increased airway reactivity.
- Increased respiratory infections.
Describe the three toxic effects of sulfur dioxide inhalation.
- Decreased lung function
- Increased respiratory symptoms.
- Increased mortality.
Describe the four toxic effects of acid aerosol inhalation.
- Decreased lung function.
- Altered mucociliary clearance.
- Increased respiratory infections.
- Increased hospitalization.
Describe the three toxic effects of particulate inhalation.
- Decreased lung function.
- Increased respiratory infections.
- Increased asthmatic attacks.
What is smog comprised of?
Ozone, oxides, and particulate matter.
Hemoglobin has a _____-fold greater affinity for CO than for O2.
200 fold
What are two clinical features of CO poisoning?
- Cherry red color of skin and mucous membranes.
2. CNS depression.
What is the treatment for CO poisoning?
Breathe pure O2, hyperbaric O2 therapy.
Lead exposure occurs through contaminated _____ and _____.
air and food
How much lead is contained in a lead paint chip 1 square cm?
170 micrograms
What is the major cause of lead poisoning amongst children?
Ingestion of lead-containing paint chips.
Ingestion of ______mg of lead per day may occur in a heavily contaminated environment.
200
What is the maximum allowable level of lead in blood for children? Can there be clinical effects below this threshold?
10 micrograms/dL. There still can be effects below this, including decreased IQ, impaired hearing, growth, nerve function.
What clinical effect does lead poisoning in adults typically have?
Peripheral neuropathy.
What clinical effect does lead poisoning in children typically have?
Centeral nervous system effects like low IQ and behavioral problems.
Compare the reversibility of lead poisoning in adults vs. in children.
CNS problems due to lead poisoning in children are typically IRREVERSIBLE, while peripheral neuropathy in adults with lead poisoning is typically reversible.
Which four systems in the body are affected by lead poisoning?
- Skeletal
- Hematopoietic
- Nervous system
- Kidneys
What physiologic effects are commonly seen in people with 11-20 milligrams/dL lead poisoning?
- Decreased Ca2+ homeostasis and as a result messed of up Vitamin D metabolism.
- Erythrocyte protoporphyrin (when RBCs incorporate zinc instead of iron into heme molecules).
- Increased nerve conduction velocity.
How does lead poisoning screw up the skeletal system (2)?
- LEAD LINES along the epiphyses in children due to abnormal bone remodeling.
- Delayed cartilage mineralization.
How does lead poisoning screw up the hematopoietic system?
- Iron incorporation into heme is impaired.
- Microcytic, hypochromic anemia.
- Basophilic stippling of RBCs.
- Hemolytic anemia due to increased fragility of cell membranes.
What does lead poisoning do to kidneys?
Damages proximal tubules
What are the treatments for lead poisoning?
Remove patient from the source. In severe cases, chelation therapy (administration of agents that will bind lead for excretion)
What is the effect of smoking on life expectancy?
Loss of 7 to 8 years
What are the most common diseases associated with smoking (3)?
- Emphysema
- Chronic bronchitis
- Lung cancer