Nursing Elites

1. Not all cells in the pancreas secrete insulin because of the hormone somatostatin, which inhibits the release of insulin by all cells. What type of intercellular chemical signal does this illustrate?

• A. Autocrine
• B. Neuromodulator
• C. Paracrine
• D. Pheromone

Correct answer: C

Rationale: The correct answer is C: Paracrine. Somatostatin acts in a paracrine manner by inhibiting the release of insulin from nearby cells within the pancreas. Paracrine signaling involves the secretion of signals that act on neighboring cells, as seen in this scenario where somatostatin affects nearby pancreatic cells without entering the bloodstream or affecting distant cells. Autocrine signaling involves cells responding to substances they themselves release, which is not the case here. Neuromodulators are chemicals that modulate the activity of neurons, not directly related to this scenario. Pheromones are chemicals released into the environment to communicate with individuals of the same species, not relevant to the signaling within the pancreas.

2. When an atom gains or loses electrons, it becomes a(n):

• A. Molecule
• B. Isotope
• C. Ion
• D. Compound

Correct answer: C

Rationale: When an atom gains or loses electrons, it becomes an ion. Gaining or losing electrons alters the atom's electron count and charge, creating a positively or negatively charged ion. A molecule is formed when two or more atoms are chemically bonded. An isotope is a variation of an element with a different number of neutrons. A compound consists of two or more different elements chemically bonded together.

3. Which type of epithelium lines the inner surface of the oral cavity, providing a barrier against external insults?

• A. Simple squamous epithelium
• B. Stratified squamous epithelium
• C. Simple columnar epithelium
• D. Pseudostratified columnar epithelium

Correct answer: B

Rationale: The oral cavity is constantly exposed to mechanical stress and potential injury from food particles and other external factors. To protect against these insults, a strong and resilient epithelium is needed. Stratified squamous epithelium is the best choice for lining the oral cavity due to its multiple layers of cells. This type of epithelium provides a robust barrier that can withstand abrasion and protect the underlying tissues. Simple squamous epithelium (choice A) is too thin and not suitable for a protective function. Simple columnar epithelium (choice C) is more suited for absorption and secretion functions, not protection against mechanical stress. Pseudostratified columnar epithelium (choice D) is found in respiratory passages and functions in mucociliary clearance, not in providing a protective barrier against external insults in the oral cavity.

4. What is the difference between mass and weight?

• A. Mass is the amount of matter in an object, whereas weight is the force of gravity acting on an object.
• B. Mass is a measure of inertia, whereas weight is a measure of the force of gravity acting on an object.
• C. Mass is measured in pounds, whereas weight is measured in kilograms.
• D. Mass is a vector quantity, whereas weight is a scalar quantity.

Correct answer: A

Rationale: Mass is the amount of matter in an object and is a scalar quantity, whereas weight is the force of gravity acting on an object and is a vector quantity. Mass remains constant regardless of the location, while weight can vary depending on the strength of gravity at different locations. Answer choice A correctly defines the difference between mass and weight, making it the correct answer. Choice B is incorrect because mass is not a measure of inertia. Choice C is incorrect as mass is typically measured in kilograms, not pounds. Choice D is incorrect as mass is a scalar quantity, and weight is a vector quantity.

5. Which factor do colligative properties of solutions depend on?

• A. Concentration of the solvent
• B. All of the above
• C. Chemical identity of the solute
• D. Number of solute particles in solution

Correct answer: D

Rationale: Colligative properties of solutions depend on the number of solute particles in solution. These properties, such as boiling point elevation, freezing point depression, vapor pressure lowering, and osmotic pressure, are proportional to the number of solute particles present in the solution. The chemical identity of the solute or the concentration of the solvent does not influence colligative properties, making choices A and C incorrect. Therefore, the correct answer is D, the number of solute particles in solution.

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