ATI RN
Practice Questions for Respiratory System Questions
Question 1 of 5
Myoglobin is a muscle hemoglobin which exhibits Hyperbolic oxygen dissociation curve indicating its great affinity towards Oxygen (Non-cooperative binding). The Hyperbolic nature of the curve is due to
Correct Answer: A
Rationale: Step-by-step rationale for choice A being correct: 1. Myoglobin is composed of a single polypeptide chain with 153 amino acids, making it monomeric. 2. Being monomeric, myoglobin does not exhibit cooperative binding, leading to a hyperbolic oxygen dissociation curve. 3. The lack of multiple subunits in myoglobin results in non-cooperative binding and a hyperbolic curve. 4. The monomeric nature allows myoglobin to have a simple structure, enhancing its affinity for oxygen. Summary of why other choices are incorrect: B: High concentration in the muscle does not directly explain the hyperbolic curve. C: Being a muscle protein does not inherently determine the hyperbolic nature of the oxygen dissociation curve. D: Quaternary structure would involve multiple subunits, leading to cooperative binding and a sigmoidal oxygen dissociation curve.
Question 2 of 5
The ED nurse is assessing the respiratory function of a teenage girl who presented with acute shortness of breath. Auscultation reveals continuous wheezes during inspiration and expiration. This finding is most suggestive of what?
Correct Answer: C
Rationale: The continuous wheezes heard on auscultation during both inspiration and expiration in a teenage girl with acute shortness of breath are highly suggestive of asthma. Asthma is characterized by airway inflammation and bronchoconstriction, leading to wheezing on both inspiration and expiration. Other choices like pleurisy typically present with sharp chest pain worsened by breathing, emphysema with decreased breath sounds and barrel chest, and pneumonia with crackles and possibly fever.
Question 3 of 5
Which of the following factors would decrease the amount of oxygen discharged by hemoglobin to peripheral tissues?
Correct Answer: D
Rationale: The correct answer is D: decreased amounts of BPG. BPG binds to hemoglobin, reducing its affinity for oxygen. Without BPG, hemoglobin holds onto oxygen tightly, decreasing its release to tissues. Increased temperature (choice A) and decreased pH (choice B) actually enhance oxygen release by hemoglobin through the Bohr effect. Decreased tissue PO2 (choice C) triggers hemoglobin to release more oxygen due to the oxygen-hemoglobin dissociation curve.
Question 4 of 5
The chloride shift occurs in order to
Correct Answer: B
Rationale: The correct answer is B because the chloride shift occurs to transport bicarbonate ions into the blood plasma. This process helps maintain acid-base balance in the body by exchanging chloride ions for bicarbonate ions to regulate pH levels. Choice A is incorrect as the chloride shift is not related to forcing oxygen into tissues. Choice C is incorrect as the chloride shift does not produce salt for the cytosol of blood cells. Choice D is incorrect as the chloride shift does not directly produce carbonic acid but rather helps in maintaining the balance of carbon dioxide and bicarbonate ions.
Question 5 of 5
Prolonged inspirations can result from stimulating the ________ center.
Correct Answer: A
Rationale: The correct answer is A: apneustic. Stimulation of the apneustic center in the brainstem prolongs inspiration by sending signals to the respiratory muscles to maintain inspiration. The apneustic center plays a role in regulating the depth and duration of breathing. Explanation for why other choices are incorrect: B: Pneumotaxic center helps regulate the respiratory rate by inhibiting inspiration, not prolonging it. C: Expiratory center is responsible for controlling expiration, not inspiration. D: Baroreceptor center is involved in regulating blood pressure, not respiratory functions.