Nokea
Emphysema is characterized by ______.
- A. the loss of elasticity of the lungs
- B. spasms of the bronchioles due to exposure to allergens
- C. abnormal growth of epithelial cells that line the bronchioles
- D. excessive mucus production in the lower respiratory pathways
Correct Answer: A
Rationale: Rationale:
A: Emphysema is characterized by the destruction of alveolar walls and loss of elasticity of the lungs, leading to air trapping and difficulty exhaling. This results in reduced gas exchange and airflow limitation.
B: Bronchospasms are more commonly associated with conditions like asthma, not emphysema.
C: Abnormal growth of epithelial cells is seen in conditions like lung cancer, not emphysema.
D: Excessive mucus production is characteristic of conditions like chronic bronchitis, not emphysema.
Summary: The correct answer is A because emphysema specifically involves the loss of elasticity of the lungs due to destruction of alveoli, leading to impaired airflow. Choices B, C, and D are incorrect as they describe features more indicative of other respiratory conditions.
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Therapy for autoimmune diseases does NOT include
- A. Immuno-suppressive drugs such as cortisone
- B. Aspirin
- C. Anti-TNF therapy
- D. Anti-CD20
Correct Answer: E
Rationale: Rationale for Correct Answer (E):
E: Surgery is the correct answer. Surgery is not typically used as a primary therapy for autoimmune diseases. Autoimmune diseases are usually treated with medications such as immuno-suppressive drugs (A), anti-inflammatory drugs (B), and targeted therapies like anti-TNF (C) and anti-CD20 (D) to manage symptoms and control the immune response. Surgery is only considered in specific cases when other treatments have failed or for complications related to the autoimmune disease. Therefore, surgery is not a standard therapy for autoimmune diseases.
Summary of Incorrect Choices:
A: Immuno-suppressive drugs like cortisone are commonly used in autoimmune disease treatment.
B: Aspirin is an anti-inflammatory drug that can help manage symptoms in some autoimmune diseases.
C: Anti-TNF therapy targets specific molecules involved in the immune response in autoimmune diseases.
D: Anti-CD20 therapy targets B cells to modulate the immune response in autoimmune diseases.
What is the primary advantage of the memory function in adaptive immunity?
- A. Rapid and stronger responses to previously encountered antigens
- B. Direct killing of pathogens without prior activation
- C. Enhanced cytokine secretion
- D. Resistance to all infections without exposure
Correct Answer: A
Rationale: The correct answer is A because memory function in adaptive immunity allows for rapid and stronger responses to previously encountered antigens. This is achieved through the presence of memory cells, such as memory B and T cells, which can quickly recognize and respond to specific pathogens upon re-exposure. This leads to a faster and more efficient immune response, providing better protection against future infections.
Choice B is incorrect because direct killing of pathogens without prior activation is a function of innate immunity, not adaptive immunity. Choice C is incorrect as enhanced cytokine secretion is not the primary advantage of memory function. Choice D is incorrect because while memory function provides protection against previously encountered antigens, it does not confer resistance to all infections without exposure.
The site of ATP synthesis in microorganisms includes:
- A. cytoplasmic membranes
- B. cell walls
- C. chloroplasts
- D. mitochondria
Correct Answer: B
Rationale: The correct answer is B: cell walls. Microorganisms, such as bacteria and archaea, do not have mitochondria or chloroplasts. ATP synthesis in microorganisms primarily occurs in the cell walls through processes like glycolysis and fermentation. Cytoplasmic membranes are involved in electron transport and ATP synthesis in prokaryotic cells, not cell walls. Chloroplasts are only present in photosynthetic organisms, not in microorganisms.
What is the normal range for the hematocrit value in a healthy adult?
- A. 20-40%
- B. 40-60%
- C. 60-80%
- D. 80-100%
Correct Answer: B
Rationale: The correct answer is B: 40-60%. Hematocrit represents the percentage of red blood cells in the blood. The normal range for hematocrit in a healthy adult is typically around 40-60%. Values below 40% may indicate anemia, while values above 60% may suggest conditions like dehydration or polycythemia. Choices A, C, and D are incorrect because they fall outside the normal range for hematocrit levels in a healthy adult.
What triggers the release of mediators from mast cells during Type I hypersensitivity?
- A. Cross-linking of IgE molecules on the mast cell surface
- B. Activation of complement proteins
- C. Binding of IgG to antigen
- D. Phagocytosis of allergens
Correct Answer: A
Rationale: The correct answer is A. Cross-linking of IgE molecules on the mast cell surface triggers the release of mediators during Type I hypersensitivity. When allergens bind to IgE antibodies on mast cells, it leads to cross-linking of IgE molecules, causing the mast cell to release histamine and other inflammatory mediators. This process initiates the allergic response.
Explanation for incorrect choices:
B: Activation of complement proteins does not directly trigger mast cell degranulation in Type I hypersensitivity.
C: Binding of IgG to antigen is characteristic of Type II and Type III hypersensitivity reactions, not Type I.
D: Phagocytosis of allergens does not directly stimulate mast cells to release mediators in Type I hypersensitivity.