Nursing Elites

1. Which of the following ions is most abundant in extracellular fluid?

• A. Calcium
• B. Chloride
• C. Sodium
• D. Potassium

Correct answer: C: Sodium

Rationale: Sodium is the most abundant ion in extracellular fluid. It plays a crucial role in maintaining fluid balance, nerve function, and muscle contraction. Calcium (Choice A) is mainly found in bones and teeth, Chloride (Choice B) is the major anion in extracellular fluid but not the most abundant ion, and Potassium (Choice D) is found predominantly inside cells.

2. In a normally functioning cardiovascular system, where does the heartbeat originate?

• A. Atrioventricular nodes
• B. Bundle of His
• C. Purkinje fibers
• D. Sinoatrial node

Correct answer: Sinoatrial node

Rationale: The correct answer is the Sinoatrial (SA) node. The SA node is known as the natural pacemaker of the heart as it initiates the electrical impulses responsible for the heartbeat. The other choices, such as the Atrioventricular (AV) nodes, Bundle of His, and Purkinje fibers, are involved in conducting the electrical signals generated by the SA node to coordinate the heart's contractions. Therefore, they do not serve as the primary origin of the heartbeat.

3. Which of the following is a result of stimulation of the sympathetic nervous system?

• A. decreased blood flow to the skeletal muscles
• B. increased cardiac output
• C. decreased respiratory rate
• D. increased urinary output

Correct answer: increased cardiac output

Rationale: Stimulation of the sympathetic nervous system leads to an increase in cardiac output. When the sympathetic nervous system is activated, it causes the heart to beat faster and with more force, leading to an increased cardiac output. Choices A, C, and D are incorrect because the sympathetic nervous system does not cause decreased blood flow to the skeletal muscles, decreased respiratory rate, or increased urinary output.

4. Testosterone production is regulated by which of the following glands?

• A. Pineal
• B. Thymus
• C. Parathyroid
• D. Pituitary

Correct answer: D

Rationale: Testosterone production is regulated by the pituitary gland. The pituitary gland secretes luteinizing hormone (LH), which stimulates the Leydig cells in the testes to produce testosterone. This hormone is not regulated by the Pineal, Thymus, or Parathyroid glands. The Pineal gland is responsible for secreting melatonin, the Thymus gland is involved in immune function, and the Parathyroid glands regulate calcium levels in the blood.

5. What do positive feedback mechanisms do?

• A. Cause long-term changes.
• B. Move conditions away from the normal state.
• C. Bring conditions back to the normal state.
• D. Usually produce stable conditions.

Correct answer: Move conditions away from the normal state.

Rationale: Positive feedback mechanisms amplify or increase changes in a system, moving conditions away from the normal state. This makes choice B the correct answer. Choice A is incorrect as positive feedback does not cause long-term changes but rather accelerates deviations from the norm. Choice C is incorrect because positive feedback does not bring conditions back to normal; instead, it amplifies deviations. Choice D is incorrect as positive feedback does not usually lead to stable conditions but rather to further deviations from the normal state.

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