Nokea
What electrolyte inactivates troponin and allows actin and myosin to form a bridge enabling fibers to contract?
- A. Magnesium.
- B. Sodium.
- C. Potassium.
- D. Calcium.
Correct Answer: D
Rationale: The correct answer is D: Calcium. Calcium is the electrolyte that inactivates troponin, allowing actin and myosin to form a bridge for muscle contraction. Calcium binds to troponin, causing a conformational change that moves tropomyosin out of the way, exposing the binding sites on actin for myosin. Magnesium (A) is important for muscle relaxation, not contraction. Sodium (B) and Potassium (C) are involved in action potential generation and propagation, not in the direct mechanism of muscle contraction.
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Anticholinergic drugs are used in Ophthalmology because they produce what effect?
- A. Pupil restriction.
- B. Decreased lacrimal secretions.
- C. Pupil dilation.
- D. Sedation.
Correct Answer: C
Rationale: The correct answer is C: Pupil dilation. Anticholinergic drugs block the action of acetylcholine, leading to pupil dilation by inhibiting the constriction of the sphincter muscle in the iris. This effect is beneficial in ophthalmology for procedures like dilation exams and treating conditions like uveitis. Choice A is incorrect as anticholinergics cause pupil dilation, not restriction. Choice B is incorrect because anticholinergics actually increase lacrimal secretions instead of decreasing them. Choice D is incorrect as sedation is not a typical effect of anticholinergic drugs in ophthalmology.
When involved in phase III drug evaluation studies, what responsibilities would the nurse have?
- A. Working with animals who are given experimental drugs.
- B. Conducting research to determine the effectiveness of the drug.
- C. Monitoring and observing patients closely for adverse effects.
- D. Choosing appropriate patients to be involved in the study.
Correct Answer: C
Rationale: The correct answer is C because in phase III drug evaluation studies, nurses are responsible for monitoring and observing patients closely for any adverse effects of the experimental drug. This is crucial to ensure patient safety and to gather data on the drug's efficacy and safety profile. Nurses play a key role in identifying and reporting any adverse reactions promptly.
Choice A is incorrect as nurses do not work with animals in drug evaluation studies.
Choice B is incorrect as conducting research to determine drug effectiveness is typically done by researchers and physicians, not nurses.
Choice D is incorrect as choosing appropriate patients for the study is usually the responsibility of the study's principal investigator or a designated research team.
A geriatric patient received a narcotic analgesic before leaving the post-anesthesia care unit to return to the regular unit. What is the priority nursing action for the nurse receiving the patient on the regular unit?
- A. Administer a non-steroidal anti-inflammatory drug.
- B. Put side rails up and place bed in the lowest position.
- C. Encourage fluids.
- D. Create a restful dark environment.
Correct Answer: B
Rationale: The correct answer is B: Put side rails up and place bed in the lowest position. This is the priority nursing action as the geriatric patient who received a narcotic analgesic may experience drowsiness or confusion, increasing the risk of falls. By putting up the side rails and lowering the bed, the nurse is ensuring the patient's safety and preventing falls. Administering a non-steroidal anti-inflammatory drug (choice A) is not the priority as the patient's safety should be addressed first. Encouraging fluids (choice C) and creating a restful dark environment (choice D) are important but not as crucial as ensuring the patient's immediate safety.
A patient asked the nurse what cardiac glycosides do to improve his condition. What is the nurse's best response?
- A. They increase heart rate.
- B. They decrease the force of myocardial contractions.
- C. They decrease conduction velocity.
- D. They help renal blood flow and increase urine output.
Correct Answer: D
Rationale: The correct answer is D because cardiac glycosides, such as digoxin, help improve heart failure by increasing renal blood flow and urine output. This occurs by inhibiting the sodium-potassium pump, leading to increased intracellular calcium levels, which in turn enhances cardiac contractility and renal perfusion. Choices A, B, and C are incorrect because cardiac glycosides do not increase heart rate, decrease the force of myocardial contractions, or decrease conduction velocity. These medications actually have a positive inotropic effect, increasing the force of myocardial contractions.
A patient diagnosed with Heart Failure would like the nurse to explain what the diagnosis means. How will the nurse explain heart failure?
- A. The heart muscle cannot pump effectively, causing a backup of blood.
- B. Increased protein leads to reduced oncotic pressure and inability to pull the fluid into the system.
- C. The hydrostatic pressure pushing fluids out of the capillary is lower than the oncotic pressure.
- D. The decrease in venous pressure from the backup of blood increases hydrostatic pressure.
Correct Answer: A
Rationale: The correct answer is A: The heart muscle cannot pump effectively, causing a backup of blood. This is the most accurate explanation of heart failure. In heart failure, the heart is unable to pump blood efficiently, leading to a backup of blood in the circulatory system. This can result in symptoms such as shortness of breath, fatigue, and fluid retention.
Explanation for why the other choices are incorrect:
B: Increased protein leading to reduced oncotic pressure is not a direct cause of heart failure.
C: This choice describes the forces involved in fluid movement, not the primary mechanism of heart failure.
D: Heart failure causes a backup of blood, which in turn increases venous pressure, not the other way around.
In summary, choice A is correct as it directly addresses the primary issue of heart failure, while the other choices focus on different physiological processes not directly related to heart failure.