Nokea
The classic pathway of complement activation begins when the protein C1 binds to:
- A. the cell wall of bacteria.
- B. the plasma membrane of bacteria.
- C. two antibodies attached to an antigen.
- D. a cell surface antigen.
Correct Answer: C
Rationale: The correct answer is C because in the classic pathway of complement activation, C1 binds to two antibodies attached to an antigen, forming an immune complex. This binding triggers a cascade of reactions leading to the activation of complement proteins. Choice A is incorrect as C1 does not bind directly to the cell wall of bacteria. Choice B is incorrect as C1 does not bind to the plasma membrane of bacteria. Choice D is incorrect as C1 does not bind directly to a cell surface antigen. The key step in the classic pathway is the recognition of immune complexes by C1, initiating the complement activation cascade.
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Which action should the nurse take first when a client develops epistaxis?
- A. Pack the affected nostril tightly with an epistaxis balloon.
- B. Apply squeezing pressure to the nostrils for 10 minutes.
- C. Obtain silver nitrate that may be needed for cauterization.
- D. Instill a vasoconstrictor medication into the affected nostril.
Correct Answer: B
Rationale: The correct action is to apply squeezing pressure to the nostrils for 10 minutes. This helps control the bleeding by promoting clot formation. It is the initial intervention to stop the bleeding before considering other options. Packing the nostril with a balloon (Choice A) may worsen the bleeding. Obtaining silver nitrate (Choice C) for cauterization is not the first-line approach. Instilling vasoconstrictor medication (Choice D) should be considered after applying pressure if bleeding persists.
Tuberculosis in man is caused by
- A. A type of bacteria
- B. A virus
- C. A protozon
- D. Malnutrition
Correct Answer: A
Rationale: The correct answer is A: A type of bacteria. Tuberculosis is caused by Mycobacterium tuberculosis, a type of bacteria. This bacterium infects the lungs and can spread to other parts of the body. The other choices (B: A virus, C: A protozoan, D: Malnutrition) are incorrect because tuberculosis is specifically caused by a bacterial infection, not a virus, protozoan, or malnutrition. Bacteria can be identified through specific staining techniques and culture methods, distinguishing them from viruses and protozoa. Malnutrition is a risk factor for developing tuberculosis but is not the direct cause of the disease.
A nurse is assisting a physician with the removal of a chest tube. The nurse should instruct the client to:
- A. Exhale slowly
- B. Stay very still
- C. Inhale and exhale quickly
- D. Perform the Valsalva maneuver
Correct Answer: D
Rationale: The correct answer is D: Perform the Valsalva maneuver. The Valsalva maneuver involves holding the breath and bearing down, which helps prevent air from entering the pleural space during chest tube removal, reducing the risk of a pneumothorax. Exhaling slowly (A) or inhaling and exhaling quickly (C) can increase the risk of air entering the pleural space. Staying very still (B) is important to minimize movement during the procedure, but performing the Valsalva maneuver is crucial to prevent complications.
A hospital nurse is participating in a drill during which many "clients" with inhalation anthrax are being admitted. The nurse would anticipate administering the following EXCEPT?
- A. Vancomycin
- B. Ciprofloxacin
- C. Doxycycline
- D. Ethambutol
Correct Answer: D
Rationale: The correct answer is D: Ethambutol. Ethambutol is not used in the treatment of inhalation anthrax. The treatment of choice for inhalation anthrax is a combination of antibiotics such as ciprofloxacin, doxycycline, and sometimes vancomycin. Ethambutol is primarily used in the treatment of tuberculosis, not anthrax. It is important for the nurse to be knowledgeable about the appropriate medications for specific conditions to provide effective care.
Which of the following statements about the chloride shift is false?
- A. It involves a movement of chloride ion into RBCs
- B. It depends on the chloride-bicarbonate countertransporter
- C. It causes RBCs to swell
- D. It is driven by a rise in PCO2
Correct Answer: C
Rationale: The correct answer is C because the chloride shift actually causes RBCs to shrink, not swell. During the chloride shift, chloride ions move out of RBCs in exchange for bicarbonate ions to maintain electrochemical equilibrium. This process helps maintain pH balance in blood. Choices A and B are correct as they accurately describe aspects of the chloride shift. Choice D is incorrect because the chloride shift is primarily driven by a decrease in PCO2, not a rise.