Nokea
What is the primary mechanism by which innate immunity differentiates between self and non-self?
- A. Somatic recombination
- B. Recognition of PAMPs via PRRs
- C. Presentation of antigens by MHC molecules
- D. Production of antibodies
Correct Answer: B
Rationale: The correct answer is B: Recognition of PAMPs via PRRs. Innate immunity distinguishes self from non-self by recognizing Pathogen-Associated Molecular Patterns (PAMPs) via Pattern Recognition Receptors (PRRs). This recognition triggers an immediate response to eliminate potential threats. Choices A, C, and D are incorrect because somatic recombination is a process in adaptive immunity, MHC molecules present antigens for recognition by T cells in adaptive immunity, and antibody production is part of adaptive immunity involving B cells.
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The industrial nurse examines an employee who complains of right shoulder pain on abduction. He points with one finger to the exact location of the pain and mentions that he won a racquetball tournament yesterday. The nurse suspects the employee is suffering from which problem?
- A. Rotator cuff tear
- B. Bursitis
- C. Dislocation
- D. Subluxation
Correct Answer: B
Rationale: The correct answer is B: Bursitis. The employee's complaint of shoulder pain on abduction, localized pain with a specific trigger (racquetball tournament), and no mention of trauma or instability suggest an inflammatory condition like bursitis. The other choices are incorrect because a rotator cuff tear typically presents with weakness, dislocation with a history of trauma and visible deformity, and subluxation with recurrent episodes of partial dislocation.
Avian Influenza has not so far caused a human pandemic because
- A. Avian flu causes only mild infection in humans compared to birds
- B. Avian flu recognize a variant of sialic acid found only on avian cells
- C. Avian flu recognizes a variant of sialic acid only found in deep tissues of humans
- D. Of cross-protection obtained from the annual vaccine
Correct Answer: C
Rationale: The correct answer is C because avian influenza has not caused a human pandemic due to the fact that it recognizes a variant of sialic acid only found in deep tissues of humans. This unique binding preference prevents efficient human-to-human transmission, which is crucial for a pandemic to occur. Choice A is incorrect as avian flu can cause severe illness in humans. Choice B is incorrect because avian flu recognizing a variant of sialic acid found only on avian cells would not prevent a pandemic in humans. Choice D is incorrect as there is no specific annual vaccine for avian influenza.
What distinguishes NK cells from other lymphocytes?
- A. They are part of adaptive immunity
- B. They do not require prior antigen sensitization
- C. They directly produce antibodies
- D. They phagocytose pathogens
Correct Answer: B
Rationale: The correct answer is B because NK cells do not require prior antigen sensitization to recognize and attack infected cells. This distinguishes them from other lymphocytes, such as T and B cells, which are part of adaptive immunity and require prior exposure to specific antigens. NK cells are part of innate immunity and can directly recognize and kill infected or abnormal cells without prior activation. Choices A, C, and D are incorrect as NK cells are not part of adaptive immunity, do not directly produce antibodies, and do not phagocytose pathogens.
Which of the following should a client with autoimmune disorder be advised to avoid?
- A. Rest during the periods of severe exacerbation
- B. Regular exercise during the periods of remission
- C. Being in crowds during the periods of immunosuppression
- D. Humid environment during the periods of remission
Correct Answer: C
Rationale: Clients with autoimmune disorders especially during immunosuppression should avoid crowds to reduce the risk of infections.
Some top-selling drugs that are currently prescribed to treat certain immune-mediated diseases are actually monoclonal antibodies specific for:
- A. An inflammatory cytokine
- B. An inflammatory cytokine receptor
- C. Lymphocytes of the T cell lineage
- D. Two of these responses are correct
Correct Answer: D
Rationale: The correct answer is D because some top-selling drugs for immune-mediated diseases target either an inflammatory cytokine or its receptor. Monoclonal antibodies specific for an inflammatory cytokine can block its activity, while those targeting the receptor can prevent the cytokine from binding and triggering immune responses. Choices A and B are correct examples of drugs targeting inflammatory pathways. Choice C, targeting T cell lymphocytes, is less common for immune-mediated diseases compared to targeting cytokines or receptors. Therefore, D is the correct answer as it encompasses both common targeting strategies.