Chapter 9- Environmental And Nutritional Disease Flashcards
What is environmental disease?
Conditions caused by exposure to chemical or physical agents in the environment
What is personal environment based on?
Individual behaviour
What is disability adjusted life year (DALY) a metric of?
Combines years lost to premature death and years lived with illness/disability
What is the single leading cause of health loss?
Under-nutrition
What contributes to increasing worldwide mortality?
HIV/AIDS
Emerging infectious disorders
How will climate change affect health?
Heat waves and air pollution- CV and respiratory disease increased
Flooding and environmental disruptions- gastroenteritis and infection epidemics
Expanding areas affected by vector-borne diseases
Crops affected- malnutrition
What are xenobiotics?
Exogenous compounds absorbed by the body
Most solvents/drugs are hydrophilic or lipophilic?
Lipophilic
What are the phases of drug metabolism?
Phase I- cytochrome P450
Phase II- metabolism into water soluble compounds (less toxic)
What are the reactions associated with Phase I metabolism?
Hydrolysis
Oxidation
Reduction
What are the reactions of Phase II metabolism?
Glucuronidation
Sulfation
Methylation
Conjugation with glutathione (antioxidant)
How does air pollution affect health?
Reduces pulmonary function
Lung inflammation
Increased airway reactivity
Diminished mucociliary clearance
Increased infections
What are some examples of outdoor pollutants and how do they cause harm?
Ozone- free radical production
SO2- conversion to sulfuric acid causes burning, dyspnea, hyperreactivity
Particulate matter- inflammation
CO- CNS depression and systemic hypoxia
What is characteristic of CO poisoning?
Cherry red colouring
What are some examples of indoor pollutants?
Wood smoke
Bioaerosols
Radon
Formaldehyde
What metals cause toxicity and how do they exert their effects?
Lead- competes with Ca, accumulation in bones and teeth, neurotoxicity, disrupts heme synthesis (anemia), GI pain and anorexia
Mercury- lipid soluble, CNS accumulation
Arsenic- inhibition of ox phos, GI, CV and neurovascular disease, skin and lung cancer (chronic low levels)
Cadmium- alveolar mac necrosis and renal tubular damage
What are common occupational health risks?
Organic solvents
Polycyclic hydrocarbons
Organochlorines
Dioxins and PCBs
Mineral dust
Vinyl chloride
BPA
Asbestos
What is the most common cause of exogenous malignancy?
Tobacco
How does tobacco affect health?
90% of lung cancers
CV and chronic pulmonary disease
Atherosclerosis and MI
Bladder and pancreatic cancer
Together with alcohol, tobacco increases the risk of what cancer?
Laryngeal
How is alcohol metabolized?
Converted in the liver to acetaldehyde and then acetate by CYPs
What are the acute symptoms of alcohol ingestion?
CNS depression
Hepatic fatty change
Gastritis
Ulceration
What are the chronic effects of alcohol consumption?
Hepatitis and cirrhosis
GI tract bleeding and esophageal varices
Wernicke-Korsakoff syndrome
Cerebral and cerebellar atrophy
Cardiomyopathy
Pancreatitis
FAS
Increased risk of many cancers
What is Wernicke-Korsakoff syndrome?
Thiamine deficiency leading to psychosis and memory disorder
What therapeutic drugs can cause injury?
Anticoagulants
HRT- endometrial dysplasia
Oral contraceptives- hepatoma
Acetaminophen
Aspirin
What are the different kinds of mechanical traumas?
Abrasion- superficial
Contusion- blunt force
Incision- smooth, clean cut
Laceration- tear/disruptive stretching
Puncture- instrument or gunshot
What are the two types of puncture?
- Penetrating- pierced
2. Perforating- entrance and exit wound
What does the clinical significance of burns depend on?
- Depth
- Percentage of body surface
- Internal injuries (inhalation)
- Promptness and efficacy of post-burn therapy
What layers do the different depths of burns effect?
- Superficial- epidermis
- Partial thickness- dermis
- Full thickness- subcutaneous
What causes hyperthermia?
Prolonged exposure to elevated temperatures
What causes hypothermia?
Prolonged exposure to low temperatures
How does hypothermia cause direct and indirect injury?
Direct- slow freezing causes large crystal formation and artifact
Indirect- vasoconstriction and increased vascular permeability
What are the effects of electrical injury?
Burns
V-fib
Cardiac/respiratory centre failure
What is the difference between ionizing and non-ionizing radiation?
Ionizing- short, high frequency waves (x and gamma)
Non-ionizing- long and low frequency (UV, IR, radio, micro and sound)
What is a curie?
Amount of radiation emitted from a source
What is a gray?
Energy absorbed by a target tissue
What is a Sievert?
The biological effect of a particular radiation dose
What affects an injury caused by ionizing radiation?
Rate of delivery
Field size
Cell proliferation
Oxygen effects/hypoxia
Vascular damage
How do high/intermediate doses of ionizing radiation differ in their effects?
High- overt necrosis
Intermediate- kills proliferating cells
What is the difference between primary and secondary malnutrition?
Primary- components are missing from diet
Secondary- malabsorption, impaired utilization/storage, excess loss or increased need
What is Marasmus?
Weight loss >60%
Protein and fat are mobilized from the somatic compartment
Serum protein levels maintained (calorie and protein reduced similarly)
What is Kwashiokor?
Protein deprivation exceeds overall calorie reduction
Loss from visceral compartment
Hypoalbuminema leads to edema
What is cachexia?
PEM I’m chronically ill patients
What is anorexia nervosa? What are its characteristics?
Self induced starvation
Amenorrhea
Reduced thyroid hormone
Reduced bone density
Sudden death- arrhythmias, hypokalemia
What is bulimia and it’s characteristics?
Binge eating followed by vomiting
Amenorrhea
Hypokalemia
Pulmonary aspiration
Esophageal and gastric rupture
How many vitamins are required for health?
13
What vitamins are fat soluble?
A, D, E and K
What are the functions of vitamin A?
Vision maintenance
Cell growth and differentiation regulation
Lipid metabolism regulation
Where is 90% of vit A found?
Ito liver cells
What are the effects of vit A deficiency?
Xerophthalmia
Keritinizing metaplasia of epithelial surfaces
Desquamation of keritinized epithelium
What are the effects of vit A toxicity?
Weight loss
Nausea
Bone/joint pain
Fracture
What is the function of vit D?
Maintenance of plasma calcium and phosphorus
Stimulates calcium reabsorption (reduces blood levels)
What are the effects of vit D deficiency?
Deficient calcium and phosphorus absorption
Bone softening and weakness
What are the two forms of vit D deficiency?
Ricket’s- children
Osteomalacia- adults
What is the function of vit C?
Collagen formation
Antioxidant
What are the effects of vit C deficiency?
Scurvy
Hemorrhage and poor healing
Inadequate bone formation in children
What is obesity?
Excess adiposity and body weight
What is adipose a source of?
Pro-inflammatory cytokines
Hormones
What are the three gut hormones and their functions?
Ghrelin- increases food intake
PYY- decreases food intake
Insulin- increased glycogen formation
What are the consequences of obesity?
Metabolic syndrome
DMII
CAD- hypertroglyceridemia and low LDL
Non-alcoholic steatohepatitis
Cholelithiasis
Hypoventilation syndrome- sleep apnea
Osteoarthritis
Cancer association
What are the symptoms of metabolic syndrome?
Visceral adiposity
Insulin resistance
Hypertension
Dyslipidemia
What dietary components may lead to the endogenous synthesis of carcinogens?
Aflatoxin (HBV)
What are common exogenous carcinogens in diet?
Pesticides and herbicides
How might diet affect atherosclerosis?
LDL:HDL ratio
