Test Bank for Pathophysiology 7th Edition by McCance

Test Bank for Pathophysiology 7th Edition by McCance

Chapter 5: Genes, Environment-Lifestyle, and Common Diseases

MULTIPLE CHOICE

1. The data reporting that sickle cell disease affects approximately 1 in 600 American blacks is an example of which concept?

ANS:  B

Prevalence rate is the proportion of the population affected by a disease at a specific point in time. Thus both the incidence rate and the length of the survival period in affected individuals determine prevalence. The incidence rate is the number of new cases of a disease reported during a specific period (typically 1 year), divided by the number of individuals in the population. A numerical expression representing a part of a larger whole or proportion is considered a ratio. Any factor that increases the chance of disease or injury is considered a risk.

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2. The ratio of the disease among the exposed population to the disease rate in an unexposed population is referred to as what type of risk?

ANS:  D

A common measure of the effect of a specific risk factor is the relative risk. Assuming a factor is the cause of a disease, attributable risk is the amount of risk that is due to that factor. A future event or circumstance that is possible but cannot be predicted with certainty is a contingency risk. The probability of the outcome is termed a causal risk factor.

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3. Empirical risks for most multifactorial diseases are based on:

ANS:  B

For most multifactorial diseases, empirical risks (i.e., risks based on direct observation of data) have been derived. The other options are not the basis for determining the empirical risk of most multifactorial diseases.

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4. What is the cause of familial hypercholesterolemia (FH)?

ANS:  C

A reduction in the number of functional LDL receptors on cell surfaces causes FH. Lacking the normal number of LDL receptors, cellular cholesterol uptake is reduced and circulating cholesterol levels increase (see Box 5-3). The other options are not the basis for developing familial FH.

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5. Which risk factor for hypertension is influenced by genetic factors and lifestyle?

ANS:  D

The most important environmental risk factors for hypertension are increased sodium intake, decreased physical activity, psychosocial stress, and obesity. However, obesity is, itself, influenced by genes and the environment.

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6. What percentage of all cases of breast cancer are identified as an autosomal dominant form?

ANS:  A

An autosomal dominant form of breast cancer accounts for approximately 5% of breast cancer cases in the United States.

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7. When a woman has one first-degree relative with breast cancer, her risk of developing breast cancer is how many times greater?

ANS:  A

If a woman has one affected first-degree relative, her risk of developing breast cancer doubles.

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8. Adoption studies have shown that the offspring of an alcoholic parent when raised by nonalcoholic parents have what amount of an increased risk of developing alcoholism?

ANS:  C

Adoption studies have shown that the offspring of an alcoholic parent, even when raised by nonalcoholic parents, have a fourfold increased risk of developing the disorder.

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9. Studies have identified several genes that play a role in the prevention of obesity by affecting what?

ANS:  A

Clinical trials using recombinant leptin have demonstrated moderate weight loss in a subset of obese individuals. In addition, leptin participates in important interactions with other components of appetite control, such as neuropeptide Y and a–melanocyte-stimulating hormone and its receptor, the melanocortin-4 receptor (MC4R). Currently, no research supports the other options as being genetically regulated.

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10. The BRCA1 and BRCA2 mutations increase the risk of which cancer in women?

ANS:  A

BRCA1 mutations increase the risk of ovarian cancer among women (20% to 50% lifetime risk), and BRCA2 mutations also confer an increased risk of ovarian cancer (10% to 20% lifetime prevalence). BRCA1 and BRCA2 mutations are not currently believed to be linked with risks of lung, uterine, or pancreatic cancers.

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11. Blood pressure variations are associated with:

ANS:  C

Significant research is now focused on specific components that may influence blood pressure variation, such as the renin-angiotensin system (involved in sodium reabsorption and vasoconstriction). The other options are not related to hypertension.

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12. The two most important risk factors for type 2 diabetes are:

ANS:  C

The two most important risk factors for type 2 diabetes are positive family history and obesity. The other options are not believed to be important risk factors for this form of diabetes.

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