ATI RN
Questions and Answers on Respiratory System Questions
Question 1 of 5
Foetal hemoglobin has a Sigmoid dissociation curve which is shifted to left relative to adult Hb because
Correct Answer: B
Rationale: The correct answer is B because foetal Hb has a lower P50 (18-20 mm Hg) than adult Hb (26.6 mm Hg). A lower P50 indicates higher oxygen affinity, allowing foetal Hb to bind oxygen more readily at lower partial pressures. This shift to the left of the dissociation curve ensures efficient oxygen transfer from the maternal bloodstream to the foetus. Choices A, C, and D are incorrect because foetal Hb having a higher P50 (A), readily accepting oxygen (C), or easily removing carbon dioxide (D) would not explain the left shift in the dissociation curve.
Question 2 of 5
While assessing a patient who has pneumonia, the nurse has the patient repeat the letter E while the nurse auscultates. The nurse notes that the patient's voice sounds are distorted and that the letter A is audible instead of the letter E. How should this finding be documented?
Correct Answer: B
Rationale: The correct answer is B: Egophony. Egophony is a lung sound in which the spoken "E" sound changes to a loud, nasal "A" sound when auscultated, indicating consolidation in the lungs, such as in pneumonia. This finding should be documented as egophony because it specifically describes the distortion of voice sounds during auscultation related to lung pathology. A: Bronchophony refers to increased clarity and loudness of spoken sounds during auscultation and is not specific to the distortion of the voice sounds as in the given scenario. C: Whispered pectoriloquy describes whispered sounds being heard clearly during auscultation, which is different from the scenario presented. D: Sonorous wheezes are continuous low-pitched wheezing sounds heard with inspiration or expiration, not related to the distortion of voice sounds as in egophony.
Question 3 of 5
The classic pathway of complement activation begins when the protein C1 binds to:
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.
Question 4 of 5
How does the pressure 'P4' at label '4' compare to the pressure 'P5' at label '5'?
Correct Answer: C
Rationale: The correct answer is C because pressure decreases as air moves from a region of higher pressure to lower pressure. At label '4', the air pressure is higher due to inhalation, and at label '5', the pressure is lower as air exits during exhalation. Therefore, P4 is always lower than P5. Choices A and B are incorrect because pressure dynamics change during inhalation and exhalation. Choice D is incorrect as pressure imbalances exist during breathing.
Question 5 of 5
Which of the following statements about the chloride shift is false?
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.