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NBCRNA PRACTICE EXAM QUESTIONS WITH
CORRECT ANSWERS AND RATIONALES JUST
RELEASED THIS YEAR
Domain 1: Anatomy, Physiology, and Pathophysiology (Questions 1-45)
1. The functional unit of the kidney responsible for filtration is the: - A) Collecting duct - B) Loop of Henle - C) Nephron - D) Glomerulus Answer: C (The nephron is the functional unit of the kidney. Each nephron consists of the glomerulus, proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting duct.) 2. Normal cardiac output in a resting adult is approximately: - A) 2-3 L/min
- B) 4-8 L/min
- C) 10-12 L/min
- D) 15-20 L/min Answer: B (Normal cardiac output ranges from 4 to 8 L/min in a resting adult, with an average of about 5 L/min. Cardiac index is cardiac output divided by body surface area, normally 2.5-4. L/min/m².) 3. The primary neurotransmitter at the neuromuscular junction is:
- A) Norepinephrine
- B) Dopamine
- C) Acetylcholine
- D) Serotonin Answer: C (Acetylcholine is the primary neurotransmitter at the neuromuscular junction, released from the motor neuron to bind to nicotinic receptors on the muscle endplate.) 4. The minimum alveolar concentration (MAC) of an inhaled anesthetic is defined as:
6. The structure that separates the right and left ventricles is the: - A) Interatrial septum - B) Interventricular septum - C) Atrioventricular septum - D) Fibrous skeleton Answer: B (The interventricular septum separates the right and left ventricles. It is thick and muscular, contributing to ventricular contraction.) 7. The parasympathetic nervous system uses which neurotransmitter at the ganglia? - A) Norepinephrine - B) Epinephrine - C) Acetylcholine - D) Dopamine
Answer: C (Acetylcholine is the neurotransmitter used by both the parasympathetic and sympathetic nervous systems at the ganglia. At the postganglionic synapse, the parasympathetic system continues to use acetylcholine.)
8. The sympathetic nervous system uses which neurotransmitter at the postganglionic synapse? - A) Acetylcholine - B) Norepinephrine - C) Epinephrine - D) Dopamine Answer: B (Norepinephrine is the primary neurotransmitter used by the sympathetic nervous system at the postganglionic synapse, except for sweat glands and some blood vessels which use acetylcholine.) 9. The primary buffer system in the extracellular fluid is the: - A) Protein buffer system - B) Phosphate buffer system
- C) 45-55 mmHg
- D) 55-65 mmHg Answer: B (Normal PaCO₂ ranges from 35 to 45 mmHg. It is a primary determinant of respiratory acid-base balance.) 12. The hormone that promotes sodium reabsorption in the kidney is:
- A) Antidiuretic hormone (ADH)
- B) Aldosterone
- C) Atrial natriuretic peptide (ANP)
- D) Cortisol Answer: B (Aldosterone promotes sodium reabsorption in the distal convoluted tubule and collecting duct of the kidney, increasing blood volume and blood pressure.) 13. Which of the following is a characteristic of Type I (slow-twitch) muscle fibers?
- A) Fast contraction speed
- B) High fatigability
- C) High oxidative capacity
- D) Low myoglobin content Answer: C (Type I muscle fibers have high oxidative capacity, are rich in mitochondria and myoglobin, and are resistant to fatigue. They are used for endurance activities.) 14. The primary determinant of cerebral blood flow is:
- A) Cardiac output
- B) Mean arterial pressure
- C) PaCO₂
- D) PaO₂ Answer: C (Cerebral blood flow is primarily determined by PaCO₂. Hypercapnia causes vasodilation and increased cerebral blood flow, while hypocapnia causes vasoconstriction and decreased blood flow.) 15. The coronary arteries receive blood flow primarily during:
- A) Systole
- A) Trachea
- B) Bronchi
- C) Bronchioles
- D) Alveoli Answer: D (The alveoli are the primary site of gas exchange in the lungs, where oxygen diffuses into the blood and carbon dioxide diffuses out.) 18. The normal hemoglobin concentration in adult males is approximately:
- A) 10-12 g/dL
- B) 13-17 g/dL
- C) 17-20 g/dL
- D) 20-24 g/dL Answer: B (Normal hemoglobin concentration is approximately 13-17 g/dL in adult males and 12 - 15 g/dL in adult females. Hemoglobin is the primary oxygen-carrying molecule in red blood cells.)
19. The neurotransmitter responsible for pain transmission in the spinal cord is: - A) Serotonin - B) Norepinephrine - C) Substance P - D) Dopamine Answer: C (Substance P is a neuropeptide involved in the transmission of pain signals in the spinal cord. It is released from primary afferent neurons and activates second-order neurons.) 20. The normal intracranial pressure (ICP) in a supine adult is: - A) 0-5 mmHg - B) 5-15 mmHg - C) 15-25 mmHg - D) 25-35 mmHg Answer: B (Normal ICP in a supine adult ranges from 5 to 15 mmHg. Elevated ICP (>20 mmHg) can impair cerebral perfusion and lead to neurologic injury.)
23. The blood-brain barrier is formed by: - A) Neurons - B) Astrocytes - C) Microglia - D) Oligodendrocytes Answer: B (The blood-brain barrier is formed by tight junctions between endothelial cells, supported by astrocytes. It restricts the passage of substances from the blood into the brain.) 24. The primary determinant of myocardial oxygen supply is: - A) Heart rate - B) Coronary perfusion pressure - C) Contractility - D) Preload
Answer: B (Coronary perfusion pressure is the primary determinant of myocardial oxygen supply. It is determined by the difference between diastolic aortic pressure and left ventricular end-diastolic pressure.)
25. The normal platelet count in adults is: - A) 50,000-100,000/μL - B) 100,000-150,000/μL - C) 150,000-400,000/μL - D) 400,000-600,000/μL Answer: C (Normal platelet count ranges from 150,000 to 400,000/μL. Thrombocytopenia is defined as a platelet count below 150,000/μL.) 26. The primary determinant of venous return is: - A) Cardiac output - B) Mean systemic filling pressure - C) Peripheral vascular resistance
- C) Concentration of urine
- D) Secretion of hormones Answer: C (The loop of Henle is responsible for the concentration of urine through the countercurrent multiplier system, which creates a concentration gradient in the renal medulla.) 29. The neuromuscular junction is located between:
- A) Two neurons
- B) A neuron and a muscle fiber
- C) A neuron and a gland
- D) Two muscle fibers Answer: B (The neuromuscular junction is the synapse between a motor neuron and a skeletal muscle fiber, where the neurotransmitter acetylcholine is released to stimulate muscle contraction.) 30. The primary function of the parasympathetic nervous system is:
- A) Fight or flight response
- B) Rest and digest response
- C) Regulation of body temperature
- D) Control of voluntary movement Answer: B (The parasympathetic nervous system is responsible for the "rest and digest" response, promoting digestion, reducing heart rate, and conserving energy.) **Domain 2: Pharmacology (Questions 46-90)
- The most potent volatile anesthetic is:**
- A) Sevoflurane
- B) Desflurane
- C) Isoflurane
- D) Halothane Answer: D (Halothane has the lowest MAC (0.75%), making it the most potent volatile anesthetic. Sevoflurane has a MAC of 1.8%, isoflurane 1.2%, and desflurane 6.6%.)
Answer: B (Neostigmine is a cholinesterase inhibitor that prevents the breakdown of acetylcholine at the neuromuscular junction, enhancing neuromuscular transmission and reversing neuromuscular blockade.)
34. Which of the following is an irreversible acetylcholinesterase inhibitor? - A) Neostigmine - B) Pyridostigmine - C) Edrophonium - D) Organophosphates Answer: D (Organophosphates irreversibly inhibit acetylcholinesterase by forming a covalent bond with the enzyme. This leads to accumulation of acetylcholine and prolonged cholinergic effects.) 35. The primary mechanism of action of propofol is: - A) GABA-A receptor potentiation - B) NMDA receptor antagonism - C) Sodium channel blockade
- D) Calcium channel blockade Answer: A (Propofol potentiates the inhibitory effects of GABA at the GABA-A receptor, enhancing chloride influx and producing sedation and hypnosis.) 36. The recommended maximum dose of lidocaine with epinephrine is:
- A) 3 mg/kg
- B) 4.5 mg/kg
- C) 7 mg/kg
- D) 10 mg/kg Answer: C (The maximum recommended dose of lidocaine with epinephrine is 7 mg/kg (maximum 500 mg). Without epinephrine, the maximum is 4.5 mg/kg.) 37. The primary mechanism of action of succinylcholine is:
- A) Depolarizing neuromuscular blockade
- B) Non-depolarizing neuromuscular blockade
- C) Central muscle relaxation
