Which of the following sentences concerned with lymph node structure is incorrect?
- A. naïve B lymphocytes are found in the cortex
- B. naïve T lymphocytes are found in the paracortex
- C. naïve lymphocytes enter the lymph node through the efferent lymphatic vessel
- D. Antigens can enter the lymph node through afferent lymphatic vessels
Correct Answer: C
Rationale: Rationale:
C is incorrect because naïve lymphocytes actually enter the lymph node through the afferent lymphatic vessel, not the efferent. A carries lymphocytes into the lymph node, and D is true since antigens enter through afferent vessels. B is correct, as naïve T cells are found in the paracortex.
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The MMR (Measles, MUMPs, Rubella) vaccine has been the object of controversy after a report (lately declared fraudulent) of an association with development of:
- A. Multiple sclerosis
- B. Autism
- C. Encephalitis
- D. Epilepsy
Correct Answer: B
Rationale: The correct answer is B: Autism. The controversy surrounding the MMR vaccine and autism emerged from a fraudulent report that falsely claimed a link between the two. Numerous scientific studies have since debunked this association, confirming the safety of the MMR vaccine. Autism is a neurodevelopmental disorder with a complex etiology, involving genetic and environmental factors, but not vaccines. Choices A, C, and D are incorrect as there is no proven causal link between the MMR vaccine and multiple sclerosis, encephalitis, or epilepsy.
Which pairing of immune response type and immune response feature is not correct?
- A. Innate: Acts rapidly
- B. Adaptive: Results in memory
- C. Innate: Mediated by lymphocytes
- D. Adaptive: Can distinguish between specific pathogens
Correct Answer: C
Rationale: The correct answer is C because innate immune response is not mediated by lymphocytes. Innate response involves physical barriers, such as skin and mucous membranes, and cells like macrophages and neutrophils. Lymphocytes are part of the adaptive immune response, which is characterized by specificity and memory. Choice A is correct as the innate response acts rapidly due to pre-existing mechanisms. Choice B is correct as adaptive response results in memory cells for quicker response upon re-exposure. Choice D is correct as adaptive response can recognize and respond to specific pathogens through antigen recognition.
Which of the following statements is NOT true?
- A. Plague or Black Death is the disease that devastated Europe in Medieval times (1350-1400) with about 50% of the European population having been wiped out.
- B. There are reports of Black Death dating as early as 1000 B.C. making plague probably the most ancient disease and the first recorded
- C. Plague is still endemic in some countries
- D. Plague can be cured with antibiotics
Correct Answer: B
Rationale: The correct answer is B because there are no reports of the Black Death dating back to 1000 B.C. The Black Death specifically refers to the pandemic outbreak of the bubonic plague in the 14th century. The first recorded pandemic of the Black Death occurred in the 14th century, not in 1000 B.C. The other choices are incorrect because A is true as the Black Death did devastate Europe in the 14th century, C is true as plague is still present in some countries, and D is true as plague can be treated with antibiotics if caught early.
Class switching of immunoglobulins occurs
- A. Usually with booster immunizations, going from IgM to IgG
- B. binds complement
- C. causes the histamine release
- D. mediates immunoglobulin class switching
Correct Answer: A
Rationale: The correct answer is A because class switching of immunoglobulins typically occurs during an immune response, leading to the production of antibodies of different classes like IgM to IgG. This process helps enhance the immune response and memory. Choice B, binding complement, refers to the function of antibodies in the classical pathway of the complement system, not class switching. Choice C, causing histamine release, is typically associated with IgE antibodies in allergic reactions, not class switching. Choice D, mediating immunoglobulin class switching, is too vague and does not provide a clear explanation compared to choice A.
A patient had abdominal surgery 3 months ago and calls the clinic with complaints of severe abdominal pain and cramping, vomiting, and bloating. What should the nurse most likely suspect as the cause of the patient’s problem?
- A. Infection
- B. Adhesion
- C. Contracture
- D. Evisceration
Correct Answer: B
Rationale: Postoperative adhesions can form after abdominal surgeries, causing obstruction and symptoms such as pain, cramping, vomiting, and bloating. Adhesions are bands of fibrous tissue that develop during the healing process.