Nokea
The major role of the complement system is to work in conjunction with
- A. antibodies to lyse cells via the C8 and C9 components
- B. the major histocompatibility complex for cell recognition
- C. antibodies to opsonize cells
- D. the T-cell receptor for production of lymphokines
Correct Answer: A
Rationale: Rationale: The complement system is a group of proteins that enhance the ability of antibodies and phagocytic cells to clear pathogens. Choice A is correct because the C8 and C9 components of the complement system form the membrane attack complex which lyses cells. Choices B, C, and D are incorrect because the complement system primarily functions independently of the major histocompatibility complex, antibodies for opsonization, and T-cell receptor for lymphokine production.
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Which of the following represents the correct sequence of host immune defenses as encountered by a pathogen?
- A. Innate responses; physical barriers; adaptive responses
- B. Physical barriers; innate responses; adaptive responses
- C. Adaptive responses; physical barriers; innate responses
- D. Physical barriers; adaptive responses; innate responses
Correct Answer: B
Rationale: The correct sequence is B: Physical barriers; innate responses; adaptive responses. Physical barriers like skin and mucous membranes are the first line of defense, followed by innate responses (e.g., inflammation, phagocytosis) that provide immediate, non-specific protection. Adaptive responses (e.g., antibody production, T cell activation) are the final defense mechanism, specifically targeting the pathogen. Choices A, C, and D are incorrect because they do not follow the correct chronological order of how host immune defenses are encountered by a pathogen. Option A and D have the innate and adaptive responses in the wrong order, while option C places adaptive responses before physical barriers, which is not accurate in terms of the sequence of host immune defenses.
What type of cell is responsible for carrying oxygen and carbon dioxide in the body?
- A. Red blood cell
- B. White blood cell
- C. Platelet
- D. Hematocrit
Correct Answer: A
Rationale: The correct answer is A: Red blood cell. Red blood cells, also known as erythrocytes, contain hemoglobin that binds to oxygen and carbon dioxide for transport in the bloodstream. They are specifically designed for gas exchange. White blood cells (B) are part of the immune system and fight infections. Platelets (C) are responsible for blood clotting. Hematocrit (D) refers to the proportion of red blood cells in the blood, not a specific type of cell responsible for gas transport.
Which of the following statements about M cells is incorrect?
- A. M cells are found in Peyer's patches in the small intestine
- B. M cells are specialized epithelial cells
- C. M' stands for microfold as these cells show small folds on their luminal side rather than microvilli
- D. They specialize in the transport by transcytosis of IgA from the lamina propria (the tissue immediately below the gut lining) into the intestinal lumen
Correct Answer: D
Rationale: The correct answer is D because M cells do not transport IgA from the lamina propria into the intestinal lumen. Instead, they transport antigens and pathogens from the gut lumen to underlying immune cells. Choice A is correct as M cells are found in Peyer's patches. Choice B is correct as M cells are specialized epithelial cells. Choice C is incorrect as M cells have microfolds on their luminal side, not microvilli.
Priority Decision: Key interventions for treating soft tissue injury and resulting inflammation are remembered using the acronym RICE. What are the most important actions for the emergency department nurse to do for the patient with an ankle injury?
- A. Reduce swelling, shine light on wound, control mobility, and elicit the history of the injury
- B. Rub the wound clean, immobilize the area, cover the area protectively, and exercise that leg
- C. Rest with immobility, apply a cold compress, apply a compress bandage, and elevate the ankle
- D. Rinse the wounded ankle, image the ankle, carry the patient, and extend the ankle with imaging
Correct Answer: C
Rationale: RICE stands for Rest, Ice, Compression, and Elevation, which are critical steps in managing acute soft tissue injuries like sprains. These actions help reduce swelling, limit further damage, and promote healing.
What disease is associated with autoantibodies binding to type IV collagen?
- A. Sarcoidosis
- B. Goodpasture's syndrome
- C. Systemic lupus erythematosus (SLE)
- D. Rheumatoid arthritis
Correct Answer: B
Rationale: The correct answer is B: Goodpasture's syndrome. This disease is specifically associated with autoantibodies targeting type IV collagen in the basement membranes of the kidneys and lungs, leading to glomerulonephritis and pulmonary hemorrhage. Sarcoidosis (A) involves non-caseating granulomas, not collagen autoantibodies. Systemic lupus erythematosus (SLE) (C) is associated with various autoantibodies but not specifically targeting type IV collagen. Rheumatoid arthritis (D) is characterized by autoantibodies against citrullinated peptides and synovial tissue, not type IV collagen.