Nokea
The action potential of a neuron
- A. is initiated by efflux of Na+
- B. is terminated by efflux of K+
- C. declines in amplitude as it moves along the axon
- D. results in a transient reversal of the concentration gradient of Na+ across the cell membrane
Correct Answer: B
Rationale: The action potential is initiated by the influx of Na+ through voltage-gated sodium channels, causing depolarization. It is terminated by the efflux of K+ through voltage-gated potassium channels, leading to repolarization. The action potential does not decline in amplitude as it propagates along the axon (all-or-none principle), and there is a net movement of Na+ and K+ across the membrane during the process.
You may also like to solve these questions
If an individual suffers a traumatic event and has a neurological disorder that means they may be unable to recall anything from the moment of the injury or to retain memories of recent events. This is known as:
- A. anterograde amnesia
- B. retrograde amnesia
- C. postevent amnesia
- D. antenatal amnesia
Correct Answer: A
Rationale: Anterograde amnesia refers to the inability to form new memories after the onset of amnesia, often due to brain injury or trauma. This condition severely impacts an individual's ability to retain information about recent events, while memories from before the injury may remain intact. It is commonly associated with damage to the hippocampus, a brain region critical for memory formation and consolidation.
A patient taking ibuprofen (Motrin) for treatment of OA has good pain relief but is experiencing increased dyspepsia and nausea with the drug's use. The nurse consults the patient's primary care provider about doing what?
- A. Adding misoprostol (Cytotec) to the patient's drug regimen
- B. Substituting naproxen (Naprosyn) for the ibuprofen (Motrin)
- C. Returning to the use of acetaminophen but at a dose of 5 g/day instead of 4 g/day
- D. Administering the ibuprofen with antacids to decrease the gastrointestinal (GI) irritation
Correct Answer: A
Rationale: Misoprostol protects the GI tract.
Mitoxantrone (Novantrone) is being considered as treatment for a patient with progressive-relapsing MS. The nurse explains that a disadvantage of this drug compared with other drugs used for MS is what?
- A. It must be given subcutaneously every day.
- B. It has a lifetime dose limit because of cardiac toxicity.
- C. It is an anticholinergic agent that causes urinary incontinence.
- D. It is an immunosuppressant agent that increases the risk for infection.
Correct Answer: B
Rationale: Mitoxantrone has a lifetime dose limit due to its potential for cardiac toxicity
During treatment of the patient with an acute attack of gout, the nurse would expect to administer which drug?
- A. Aspirin
- B. Colchicine
- C. Allopurinol (Zyloprim)
- D. Probenecid (Benemid)
Correct Answer: B
Rationale: Colchicine treats acute gout attacks.
The following may cause an elevated blood urea:
- A. renal disease
- B. steroid therapy
- C. dehydration
- D. all above
Correct Answer: D
Rationale: Elevated blood urea can result from renal disease, steroid therapy, or dehydration due to reduced renal perfusion or increased protein catabolism.