ATI LPN
Questions for Respiratory System Questions
Question 1 of 5
Respiratory peripheral chemoreceptors:
Correct Answer: D
Rationale: peripheral chemoreceptors (carotid/aortic bodies) increase firing when POâ‚‚ drops below 100 mmHg (e.g., 60 mmHg threshold). Choice A is true; carotid bodies sense all three. Choice B is false; central response to pCOâ‚‚ dominates. Choice C is wrong; aortic bodies are in the arch, not valve. Choice E is false; they sense arterial POâ‚‚. D reflects their hypoxia sensitivity, critical for ventilation drive.
Question 2 of 5
Halving the radius of an airway increases resistance:
Correct Answer: D
Rationale: halving radius (r) increases resistance (R) 16-fold per Poiseuille's law (R ∠1/râ´). If r becomes r/2, R = 1/(r/2)â´ = 16/râ´. Choice A (2x) is linear. Choice B (4x) is r². Choice C (8x) is r³. Choice E (no effect) ignores physics. In airways (e.g., bronchoconstriction), small changes amplify resistance (e.g., 2 mm to 1 mm, R rises 16x), impacting flow significantly. D reflects this exponential relationship accurately.
Question 3 of 5
Which respond to mechanical and chemical stimulation?
Correct Answer: D
Rationale: nose and upper airway receptors respond to mechanical (e.g., flow) and chemical (e.g., irritants) stimuli, triggering sneeze/cough. Choice A (central) is pH-based. Choice B (carotid) and C (aortic) sense blood gases. Choice D (stretch) is mechanical only. Trigeminal/vagal innervation in upper airways detects both types, distinguishing G as the match.
Question 4 of 5
Regarding the neural control of breathing, which statement is INCORRECT?
Correct Answer: D
Rationale: ventral respiratory group (VRG) neurons include expiratory cells that discharge spontaneously in forced breathing, not silent as stated. Choice A is true; centers and chemoreceptors are distinct. ' quiet expiration is passive (recoil). Choice C is accurate; inspiratory neurons (DRG) drive phrenic nerves. Choice E (12-15/min) fits. VRG's role in active expiration contradicts D's ‘no discharge,' making it false.
Question 5 of 5
Which of the following is NOT involved in the control of ventilation?
Correct Answer: C
Rationale: the basal ganglia regulate movement, not ventilation directly. Choice A (peripheral chemoreceptors) senses POâ‚‚/PCOâ‚‚/pH, driving breathing. Choice B (stretch receptors) modulates via Hering-Breuer reflex. Choice D (pons) refines rhythm (pneumotaxic center). Choice E (muscles) executes. The medulla (not listed) is primary, with pons and receptors integrating, but basal ganglia's role in motor disorders (e.g., Parkinson's) doesn't extend to respiratory control, making C the outsider.