NR 507 Week 1 Quiz 2

NR 507 Week 1 Quiz 2 What of the following remains a significant cause of morbidity and mortality worldwide? Infectious disease Despite the wide scale implementation of progressive public health and immunization policies, infectious disease remains a significant cause of morbidity and mortality. Which statement about vaccines is true? Vaccines require booster injections to maintain lifelong protection. In general, vaccine-induced protection does not persist as long as infection-induced immunity, thus booster injections may be necessary to maintain protection throughout life. After sexual transmission of HIV, a person can be infected yet seronegative for _____ months. 6 to 14 Antibody appears rather rapidly after infection through blood products, usually within 4 to 7 weeks. After sexual transmission, however, the individual can be infected yet seronegative for 6 to 14 months or, in at least one case, for years. Cells in _____ may act as a reservoir in which HIV can be relatively protected from antiviral drugs. the central nervous system HIV may persist in regions where the antiviral drugs are not as effective, such as the CNS. Once they have penetrated the first line of defense, which microorganisms do neutrophils actively attack, engulf, and destroy by phagocytosis? Bacteria Invasion results in direct confrontation with an individual’s primary defense mechanisms against bacteria, which include the complement system, antibodies, and phagocytes, such as neutrophils and macrophages. Which statement is true about fungal infections? They are controlled by phagocytes and T lymphocytes. The host defense against fungal infection includes the fungistatic properties of neutrophils and macrophages. T lymphocytes are crucial in limiting the extent of infection and producing cytokines to further activate macrophages. In a type II hypersensitivity reaction, when soluble antigens from infectious agents enter circulation, tissue damage is a result of neutrophil granules and toxic oxygen products The components of neutrophil granules, as well as the several toxic oxygen products produced by these cells, damage the tissue. Hypersensitivity is best defined as a(n) altered immunologic response to an antigen that results in disease Hypersensitivity is an altered immunologic response to an antigen that results in disease or damage to the host. A person with type O blood is likely to have high titers of anti-___ antibodies. A and B Type O individuals, who have neither A or B antigen but have both anti-A and anti-B antibodies, cannot accept blood from any of the other three types. During an IgE-mediated hypersensitivity reaction, what causes bronchospasm? Smooth muscle contraction caused by histamine bound to H1 receptors Acting through the H1 receptors, histamine contracts bronchial smooth muscles, causing bronchial constriction; increases vascular permeability, causing edema; and causes vasodilation, increasing blood flow into the affected area (Figures 6-3 and 6-10). Deficiencies in which element can produce depression of both B- and T-cell function? Zinc Deficient zinc intake can profoundly depress T- and B-cell function What is the mechanism in type III hypersensitivity reactions? Antibodies bind to soluble antigens that were released into body fluids and the immune complexes are deposited in the tissues. Most type III hypersensitivity diseases are caused by antigen-antibody (immune) complexes that are formed in the circulation and deposited later in vessel walls or extravascular tissues (Figure 8-3). What is the mechanism in type II hypersensitivity reactions? Antibodies bind to the antigens on the cell surface. All of these mechanisms begin with antibody binding to tissue-specific antigens or antigens that have attached to particular tissues. First, the cell can be destroyed by antibody (IgG or IgM) and activation of the complement cascade through the classical pathway. Exhaustion occurs if stress continues and _____ is not successful. Adaptation Exhaustion occurs if stress continues and adaptation is not successful, ultimately causing impairment of the immune response, heart failure, and kidney failure, leading to death. What effect does estrogen have on lymphocytes? Depression of T cells and enhancement of B cells Estrogens generally are associated with a depression of T-cell–dependent immune function and enhancement of B-cell functions. Stress-induced norepinephrine results in peripheral vasoconstriction. Norepinephrine regulates blood pressure by constricting smooth muscle in all blood vessels. During stress, norepinephrine raises blood pressure by constricting peripheral vessels. During a stress response, increased anxiety, vigilance, and arousal is prompted by norepinephrine. Norepinephrine release promotes arousal, increased vigilance, increased anxiety, and other protective emotional responses. Intestinal polyps are benign neoplasms and the first stage in development of colon cancer. These findings support the notion that an accumulation of mutations in specific genes is required for the development of cancer. It is understood that multiple genetic mutations are required for the evolution of full-blown cancer. The remaining options do not address the progression of benign to metastatic tumors Which of the viruses below are oncogenic DNA viruses? Papovaviruses, adenoviruses, and herpesviruses Papovaviruses, adenoviruses, and herpesviruses are oncogenic DNA viruses; the remaining examples do not fall into this category. By what process does the ras gene convert from a proto-oncogene to an oncogene? By alternating one or more nucleotide base pairs A point mutation is the alteration of one or a few nucleotide base pairs. This type of mutation can have profound effects on the activity of proteins. A point mutation in the ras gene converts it from a regulated protooncogene to an unregulated oncogene, an accelerator of cellular proliferation. The remaining options do not describe point mutation as it affects the conversion of a ras gene. Many cancers create a mutation of ras. What is ras? An intracellular signaling protein that regulates cell growth Up to one third of all cancers have an activating mutation in the gene for an intracellular signaling protein called ras. This mutant ras stimulates cell growth even when growth factors are missing. The remaining options do not describe ras. Which of the following represents the correct nomenclature for benign and malignant tumors of adipose tissue, respectively? Lipoma, liposarcoma In general, cancers are named according to the cell type from which they originate (e.g., lip), whereas benign tumors use the suffix “- oma.” In chronic myeloid leukemia (CML), a piece of chromosome 9 fuses to a piece of chromosome 22. This is an example of which mutation of normal genes to oncogenes? Chromosome translocation Chromosome translocations, in which a piece of one chromosome is translocated to another chromosome, can activate oncogenes. In a different type of leukemia, CML, a specific chromosome translocation is almost always present. The remaining options are not best depicted by CML. Tobacco smoking is associated with cancers of all of the following except skin. Smoking causes cancer of the lung and is associated with cancers of the renal gland, bladder, penis, oral cavity, pharynx, larynx, nasal cavities, sinuses, esophagus, stomach, liver, kidney, uterus, and myeloid leukemia. There are no data currently linking the tobacco smoking skin cancer What congenital malformation is commonly linked to acute leukemia in children? Down syndrome Trisomy 21 (Down syndrome) is the most common genetic defect linked to the development of acute leukemia. Children with Down syndrome have a 10- to 20-fold increased risk of developing acute lymphoblastic and myelogenous leukemia and a higher risk for developing acute megakaryocytic leukemia. There are no current data to support a link between the other stated congenital malformations and acute leukemia