Nursing Elites

1. What are Merkel cells, located in the epidermis, specialized for?

• A. Melanin production
• B. Temperature sensation
• C. Touch perception
• D. Immune defense

Correct answer: C

Rationale: Merkel cells are specialized touch receptors located in the epidermis of the skin. Their primary function is to perceive light touch and pressure. They play a crucial role in the sensory perception of touch stimuli. Option A, melanin production, is incorrect because Merkel cells are not involved in producing melanin. Option B, temperature sensation, is incorrect as Merkel cells are not specialized for sensing temperature. Option D, immune defense, is also incorrect as Merkel cells do not have a role in immune defense mechanisms.

2. Which vitamin requires intrinsic factor for proper absorption?

• A. Vitamin A
• B. Vitamin C
• C. Vitamin D
• D. Vitamin B12

Correct answer: D

Rationale: Vitamin B12 requires intrinsic factor, a glycoprotein secreted by the parietal cells of the stomach, for proper absorption in the small intestine. Intrinsic factor binds to vitamin B12 and facilitates its absorption in the ileum. Deficiency in intrinsic factor can lead to pernicious anemia, a condition characterized by a lack of vitamin B12 absorption. Options A, B, and C are incorrect. Vitamin A is absorbed in the small intestine with the help of bile salts; Vitamin C is absorbed in the small intestine via active transport; Vitamin D is absorbed in the small intestine through a process involving bile salts and micelles. It is essential for students to understand this relationship as it highlights the importance of intrinsic factor in the absorption of specific vitamins and the consequences of its deficiency.

3. Which of the following statements is true about an allergic reaction?

• A. An allergic reaction, such as hives or wheezing, results from overactive body systems such as the integumentary and respiratory systems.
• B. An allergic reaction is a result of overactive B-cells in the body that release various immunoglobulins.
• C. An allergic reaction is caused by overactive mast cells in the body, which are stimulated by Immunoglobulin E.
• D. An allergic reaction involves substances like histamine, keratin, and collagen.

Correct answer: C

Rationale: The correct answer is C. Mast cells are responsible for releasing histamine and other chemicals during an allergic response. Choice A is incorrect because hives and wheezing are symptoms of an allergic reaction, not the causes. Choice B is incorrect as B-cells are not directly involved in allergic reactions. Choice D is incorrect as keratin and collagen are not typically involved in allergic reactions, and histamine is released by mast cells.

4. Which of the following types of stem cells can differentiate into any cell type, including forming an entire organism?

• A. Totipotent stem cells
• B. Multipotent stem cells
• C. Pluripotent stem cells
• D. Hematopoietic stem cells

Correct answer: A

Rationale: Totipotent stem cells possess the unique ability to differentiate into any cell type, including forming an entire organism. These cells have the highest potency level and can give rise to both embryonic and extraembryonic cell types, allowing them to develop into a complete organism. Multipotent stem cells (Choice B) can differentiate into a limited range of cell types within a specific tissue or organ. Pluripotent stem cells (Choice C) can differentiate into any cell type in the body except for those needed to support and develop a fetus. Hematopoietic stem cells (Choice D) are a type of multipotent stem cell that can differentiate into various blood cell types.

5. What is the basic structural and functional unit of the nervous system?

• A. Axon
• B. Neuron
• C. Dendrite
• D. Synapse

Correct answer: B

Rationale: The correct answer is B: Neuron. Neurons are indeed the basic structural and functional units of the nervous system. Neurons are specialized cells that transmit signals throughout the nervous system, enabling communication and coordination of various functions within the body. While axons, dendrites, and synapses are all essential components of neurons and neural function, the neuron as a whole is considered the fundamental building block responsible for signal transmission. Choice A, Axon, is incorrect because an axon is a part of a neuron responsible for transmitting electrical signals away from the cell body. Choice C, Dendrite, is incorrect because dendrites are extensions of a neuron that receive signals from other neurons. Choice D, Synapse, is incorrect because a synapse is the junction between two neurons where signals are transmitted.

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