Nursing Elites

1. Neurotransmitters send chemical messages across the gap between one neuron and another through which of the following structures?

• A. Schwann cell
• B. ganglion
• C. synapse
• D. axon

Correct answer: C

Rationale: Neurotransmitters send chemical messages across the gap between one neuron and another through a structure called the synapse. The synapse is a specialized junction where the axon of one neuron meets the dendrite or cell body of another neuron. Neurotransmitters are released from the axon terminal of the presynaptic neuron and travel across the synaptic cleft to bind to receptors on the postsynaptic neuron, transmitting the signal between the two neurons. Choice A, Schwann cell, is incorrect as Schwann cells are responsible for producing myelin sheath around axons in the peripheral nervous system, not for transmitting neurotransmitters between neurons. Choice B, ganglion, is incorrect as ganglia are clusters of nerve cell bodies outside the central nervous system and do not directly participate in the transmission of chemical messages between neurons. Choice D, axon, is incorrect as the axon is a long, slender projection of a neuron that conducts electrical impulses away from the cell body and towards the axon terminals, where neurotransmitters are released into the synapse, but it is not the structure across which neurotransmitters travel to communicate between neurons.

2. Dendrites are finger-like extensions found on

• A. Muscle cells
• B. Connective tissue cells
• C. Neurons
• D. Epithelial cells

Correct answer: C

Rationale: Dendrites are the branched extensions of neurons that receive signals from other neurons and transmit those signals to the cell body. They play a crucial role in the communication process within the nervous system, allowing neurons to communicate with each other and integrate incoming signals to generate responses. The other choices are incorrect because dendrites specifically belong to neurons, not muscle cells, connective tissue cells, or epithelial cells.

3. If a scientist finds that the results of her experiment seem to contradict her hypothesis, what is the best course of action?

• A. Publish the results anyway, acknowledging that her hypothesis seems to have been incorrect.
• B. Keep trying the experiment until the results match her hypothesis.
• C. Publish the results, retroactively changing the hypothesis.
• D. None of the above; this cannot occur. The experimental results cannot contradict the hypothesis, by definition.

Correct answer: A

Rationale: The best course of action is to publish the results anyway, acknowledging that her hypothesis seems to have been incorrect. Science relies on accurate reporting and transparency, even if the results do not align with the original hypothesis. This allows for further discussion, analysis, and potentially new hypotheses to be developed based on the findings. It is essential in scientific research to report both positive and negative results to contribute to the body of knowledge and advance understanding in the field. Choice B is incorrect because persisting with the same experiment to force results to align with the hypothesis goes against scientific integrity and may lead to biased conclusions. Choice C is incorrect as changing the hypothesis after obtaining results is not scientifically sound and undermines the credibility of the research. Choice D is incorrect because science embraces the possibility of experimental results contradicting hypotheses, as this provides valuable insights for refining theories and expanding scientific knowledge.

4. Lymph nodes, found along lymphatic vessels, are important for:

• A. Storing blood
• B. Producing antibodies
• C. Filtering lymph and trapping harmful substances
• D. All of the above

Correct answer: C

Rationale: Lymph nodes are essential for filtering lymph and trapping harmful substances. They are a vital part of the immune system as they remove pathogens and harmful substances from the lymph before it returns to the bloodstream. Lymph nodes do not store blood or produce antibodies, making choice C the correct answer. Choice A is incorrect because lymph nodes do not store blood; they primarily filter lymph. Choice B is incorrect as lymph nodes do not produce antibodies; that function is mainly carried out by specialized cells within the immune system. Choice D is incorrect as lymph nodes do not perform all the functions listed, making it an incorrect answer.

5. Dense irregular connective tissue, found in tendons and ligaments, provides:

• A. Flexibility
• B. Lubrication
• C. Insulation
• D. Tensile strength

Correct answer: D

Rationale: Dense irregular connective tissue, found in tendons and ligaments, provides tensile strength. Tendons and ligaments need to withstand tension and forces acting upon them, and the dense irregular connective tissue helps provide this strength and support. Choice A, flexibility, is incorrect because tendons and ligaments primarily provide support and stability rather than flexibility. Choice B, lubrication, is not the main function of dense irregular connective tissue in tendons and ligaments. Choice C, insulation, is also incorrect as this tissue type is not primarily involved in providing insulation.

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