Nursing Elites

1. What is the primary function of the myelin sheath that surrounds some axons in the nervous system?

• A. To initiate nerve impulses
• B. To transmit sensory information
• C. To speed up the transmission of nerve impulses
• D. To connect neurons at synapses

Correct answer: c

Rationale: The primary function of the myelin sheath that surrounds some axons in the nervous system is to speed up the transmission of nerve impulses. The myelin sheath acts as an insulating layer, which helps nerve impulses travel faster along the axon by allowing them to 'jump' from one node of Ranvier to the next, a process known as saltatory conduction. This increases the efficiency and speed of signal transmission, enabling rapid communication within the nervous system. Therefore, option C is the correct answer as it accurately describes the role of the myelin sheath in enhancing the speed of nerve impulse transmission.

2. According to the wave theory of light, the bright fringes observed in a double-slit experiment correspond to:

• A. Constructive interference
• B. Destructive interference
• C. Increased diffraction
• D. Total internal reflection

Correct answer: A

Rationale: The correct answer is A: Constructive interference. According to the wave theory of light, when two light waves meet in phase (crest to crest or trough to trough), they combine to produce a brighter fringe. This is known as constructive interference, leading to the formation of bright fringes in a double-slit experiment. Destructive interference, on the other hand, occurs when two waves are out of phase (crest to trough), resulting in a dimmer or dark fringe. Increased diffraction refers to the bending of light waves around obstacles, not the formation of bright fringes. Total internal reflection is a phenomenon that occurs at the boundary between two different mediums when light is reflected back into the original medium. Therefore, the bright fringes observed in a double-slit experiment correspond to constructive interference.

3. Which of the following terms refers to the abnormal sound heard during a stethoscope examination, potentially indicating a heart valve issue?

• A. Tachycardia
• B. Bradycardia
• C. Heart murmur
• D. Arrhythmia

Correct answer: D

Rationale: The correct answer is D: Arrhythmia. An arrhythmia refers to an irregular heart rhythm, which can manifest as abnormal sounds heard during a stethoscope examination. Tachycardia (A) and bradycardia (B) both pertain to heart rate abnormalities, with tachycardia indicating a fast heart rate and bradycardia a slow heart rate. However, these terms do not specifically relate to abnormal sounds. Heart murmur (C) is the term that refers to the abnormal sound heard during a stethoscope examination, potentially indicating a heart valve issue. Therefore, the correct answer is D as it best fits the description provided in the question.

4. The word "obscurity" can be replaced with which of the following without changing the meaning?

• A. Prominence
• B. Seclusion
• C. Destruction
• D. Transformation

Correct answer: B

Rationale: Both "obscurity" and "seclusion" imply being hidden or unknown. Prominence, destruction, and transformation do not convey the same meaning.

5. Which sentence uses the pronoun "they" correctly?

• A. Her friends told her they liked her new haircut.
• B. Sarah and I, they went to the movies.
• C. They gave the awards to whomever deserved them.
• D. The birds, they were singing in the trees.

Correct answer: A

Rationale: Option A agrees with the closest noun, "friends."

6. What is the oxidation state of carbon in CH4?

• A. +1
• B. -1
• C. +2
• D. -4

Correct answer: d

Rationale: Each hydrogen atom has an oxidation state of +1, and the sum of oxidation states in CH4 is 0. Therefore, carbon has an oxidation state of -4.

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