Nokea
Which of the following statement is incorrect
- A. Antigens in tissues can reach regional LN via afferent lymphatic vessels
- B. Migrating dendritic cells that have collected antigens in tissues enter the draining LN via HEV
- C. During an infection fever and other inflammatory signals induce increased blood flow to draining LN and increased chances for lymphocytes to migrate from blood into LN
- D. The thoracic duct returns most of the circulating lymphocytes back to blood
Correct Answer: B
Rationale: The correct answer is B because migrating dendritic cells do not enter the draining lymph node (LN) via high endothelial venules (HEV); instead, they enter through afferent lymphatic vessels. HEVs are specialized post-capillary venules in LN where lymphocytes enter from the bloodstream. Dendritic cells, carrying antigens from tissues, travel via afferent lymphatic vessels to reach the LN where they present antigens to lymphocytes. Option A is correct as antigens in tissues reach LN via afferent lymphatic vessels. Option C is correct as infection-induced signals can increase blood flow to LN, facilitating lymphocyte migration. Option D is incorrect because the thoracic duct returns lymph back to the bloodstream, not specifically lymphocytes.
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Which of the following precautions must a nurse take while caring for clients with HIV/AIDS to reduce occupational risks?
- A. Transport specimens of body fluids in leak proof containers.
- B. Seek prescription for a fusion inhibitor to reduce risk of infection.
- C. Avoid administering IV drugs.
- D. Avoid cleaning the client’s room,especially cleaning urine,stoolor vomit.
Correct Answer: A
Rationale: Transporting specimens in leak-proof containers minimizes the risk of exposure to infectious body fluids.
The reason for naming the closed circulatory systems
- A. Carries blood in opens vessels
- B. Moves blood through the veins and arteries
- C. Blood stays confined to vessels
- D. Returns blood to the heart
Correct Answer: C
Rationale: The correct answer is C because a closed circulatory system means that blood stays confined to vessels, providing efficient transport and preventing blood loss. Option A is incorrect because a closed system does not have open vessels. Option B is incorrect because veins and arteries are part of both closed and open circulatory systems. Option D is incorrect because returning blood to the heart is a function of both closed and open circulatory systems.
Why do we constantly need new flu vaccines?
- A. Because flu viruses mutate frequently due to their error-prone RNA polymerase
- B. Because completely new variants can be created from an assortment of previously circulating strains due the segmented nature of the viral genome
- C. Because antibodies generated in vaccinated people are short-lived and need to be generated again with a new vaccine injection
- D. Both A and B are correct
Correct Answer: D
Rationale: The correct answer is D. Choice A is correct because flu viruses mutate frequently due to their error-prone RNA polymerase, leading to new strains. Choice B is correct because the segmented nature of the viral genome allows for reassortment of different strains, creating completely new variants. Therefore, new vaccines are needed to target these evolving strains. Choice C is incorrect as the need for new vaccines is primarily driven by the genetic variability of the virus, not solely by the short-lived nature of antibodies. Thus, choices A and B together provide a comprehensive explanation for the constant need for new flu vaccines.
What is the function of MHC molecules on antigen-presenting cells?
- A. Secreting cytokines
- B. Binding and destroying pathogens
- C. Displaying antigen fragments for T cell recognition
- D. Producing antibodies
Correct Answer: C
Rationale: The correct answer is C, displaying antigen fragments for T cell recognition. MHC molecules bind to antigen fragments and present them on the cell surface for T cells to recognize. This process is crucial for activating the immune response. Choice A is incorrect as MHC molecules do not secrete cytokines. Choice B is incorrect as MHC molecules do not directly destroy pathogens. Choice D is incorrect as MHC molecules do not produce antibodies; that is the function of B cells.
When teaching the patient with cancer about chemotherapy, which approach should the nurse take?
- A. Avoid telling the patient about possible side effects of the drugs to prevent anticipatory anxiety
- B. Explain that antiemetics,antidiarrheals and analgesics will be provided as needed to control side effects
- C. Assure the patient that the side effects from chemotherapy are uncomfortable but never life threatening
- D. Inform the patient that chemotherapy-related alopecia is usually permanent but can be managed with lifelong use of wigs
Correct Answer: B
Rationale: Providing information about available supportive therapies helps patients manage side effects effectively.