Nursing Elites

1. What is the function of the sinuses?

• A. To trap many airborne pathogens
• B. To direct air down the trachea rather than the esophagus
• C. To warm, humidify, and filter air
• D. To sweep away pathogens and direct them toward the top of the trachea

Correct answer: C

Rationale: The correct function of the sinuses is to warm, humidify, and filter the air we breathe. Sinuses play a crucial role in preparing the air for the respiratory system by adding moisture, warmth, and filtering out particles. Choice A is incorrect because while sinuses can help filter some particles, their primary function is not to trap pathogens. Choice B is incorrect as the sinuses do not control the direction of air down the trachea; this is regulated by the epiglottis and vocal cords. Choice D is incorrect as sinuses do not sweep pathogens away or direct them towards the trachea; instead, they condition the air for respiration.

2. Which of the following units is used to express concentration as a mass of solute per unit volume of solution?

• A. Molality (m)
• B. Molarity (M)
• C. Weight percent (%)
• D. Parts per million (ppm)

Correct answer: A

Rationale: Molality (m) is the unit used to express concentration as a mass of solute per unit volume of solution. It is calculated by dividing the mass of solute in grams by the mass of the solvent in kilograms. Molality is preferred over molarity when there are large temperature variations as it is temperature-independent, making it a more accurate measure of concentration. Molarity (B) is the unit used to express concentration as moles of solute per liter of solution, weight percent (C) is the mass of solute per 100 parts of the total mass of the solution, and parts per million (D) is used to express very small concentrations where 1 ppm is equivalent to 1 mg of solute per liter of solution.

3. 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.

4. What is a temporary loss of consciousness due to insufficient blood flow to the brain called?

• A. Stroke
• B. Seizure
• C. Syncope (fainting)
• D. Coma

Correct answer: C

Rationale: Syncope, also known as fainting, is a temporary loss of consciousness caused by insufficient blood flow to the brain. It results from a brief interruption in the brain's blood supply, leading to a temporary loss of consciousness. The correct answer is C. A stroke, option A, is caused by a blockage or rupture of blood vessels in the brain, not insufficient blood flow. Seizure, option B, involves a sudden surge of electrical brain activity, not reduced blood flow. Coma, option D, is characterized by prolonged unconsciousness, not a temporary loss of consciousness due to insufficient blood flow.

5. Which of the following statements about fungi is FALSE?

• A. They can be unicellular or multicellular
• B. They are all parasitic and cause disease in humans
• C. They play a vital role in decomposition and nutrient cycling
• D. Some are used in food production, like mushrooms

Correct answer: B

Rationale: A) This statement is true. Fungi can exist in both unicellular (yeast) and multicellular (molds and mushrooms) forms. B) This statement is false. While some fungi can be parasitic and cause diseases in humans, not all fungi exhibit this behavior. Many fungi are beneficial and play essential roles in ecosystems. C) This statement is true. Fungi are crucial for decomposition and nutrient cycling in ecosystems. They break down organic matter and recycle nutrients back into the environment. D) This statement is true. Some fungi, like mushrooms, are used in food production and are consumed by humans.

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