Nursing Elites

1. Positive feedback mechanisms usually result in

• A. changes returning values away from a set point.
• B. stable conditions around a set point.
• C. unstable conditions.
• D. long-term changes.

Correct answer: C

Rationale: Positive feedback mechanisms usually result in unstable conditions. In a positive feedback loop, the output enhances or amplifies the changes that are occurring, leading to a deviation from the initial set point. Therefore, positive feedback does not bring values back towards the set point (Choice A). Choice B is incorrect because positive feedback does not promote stability around a set point. Choice D is also incorrect as positive feedback mechanisms typically do not lead to long-term changes; instead, they intensify the initial change, causing instability.

2. Does aging begin in the fetus?

• A. Yes
• B. No
• C. Not Sure
• D. None of the above

Correct answer: A

Rationale: Aging does begin in the fetus. The aging process starts even before birth due to cellular changes and the passage of time. The cells in a fetus undergo growth, division, and aging from the moment of conception. This continual process of cellular aging continues throughout life. Therefore, the statement is true. Choice B is incorrect because aging does initiate during the fetal stage. Choice C is incorrect as the process of aging commences in the fetus. Choice D is incorrect as the correct answer is 'Yes,' indicating that aging does start in the fetus.

3. Cells do not aggregate into organelles based on similar functions.

• A. TRUE
• B. FALSE
• C. Not Sure
• D. None of the above

Correct answer: B

Rationale: The statement is false. Cells with similar functions do not aggregate into organelles. Organelles are specialized structures within cells that perform specific functions, such as the nucleus, mitochondria, and endoplasmic reticulum. Cells themselves are the basic structural and functional units of organisms, and organelles are located within cells to carry out various tasks. Therefore, cells do not aggregate into organelles, but organelles are found within cells to support their functions. Choices A, C, and D are incorrect as cells do not form organelles by aggregating based on similar functions.

4. Signs of aging at the cellular level are

• A. graying hair, waning strength, and wrinkles.
• B. unrepaired DNA and abnormal proteins.
• C. impaired cell division and the ability to break down and recycle worn cell parts.
• D. a fatty liver and clogged blood vessels.

Correct answer: C

Rationale: The correct answer is 'impaired cell division and the ability to break down and recycle worn cell parts.' Aging at the cellular level involves reduced efficiency in cell division and the breakdown/recycling of cellular components, leading to functional decline. Choices A, B, and D are incorrect because they involve external physical manifestations or organ-specific issues rather than cellular-level changes associated with aging.

5. 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: D

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.

Similar Questions