Nursing Elites

1. What two factors enable some intercellular chemical signals to diffuse across cell membranes and bind to intracellular receptors?

• A. They are small and soluble.
• B. They are large and soluble.
• C. They are small and insoluble.
• D. They are large and insoluble.

Correct answer: A

Rationale: The correct answer is A: 'They are small and soluble.' Small and soluble molecules can easily pass through cell membranes and bind to intracellular receptors. Being small allows them to pass through the membrane, while being soluble enables them to dissolve in the aqueous environment inside the cell. Choice B is incorrect because large molecules typically cannot pass through the cell membrane easily. Choices C and D are incorrect because insoluble molecules would not dissolve in the aqueous environment inside the cell, hindering their ability to bind to intracellular receptors.

2. What type of intermolecular force is responsible for the high surface tension of water?

• A. Hydrogen bonding
• B. London dispersion forces
• C. Ionic bonding
• D. Metallic bonding

Correct answer: A

Rationale: The high surface tension of water is primarily due to the strong hydrogen bonding between water molecules. Hydrogen bonding is a specific type of intermolecular force that occurs between a hydrogen atom covalently bonded to a highly electronegative atom, like oxygen in water, and another electronegative atom nearby. This unique interaction results in a strong attraction between water molecules at the surface, leading to the cohesive forces responsible for the high surface tension of water. Choices B, C, and D are incorrect because London dispersion forces, ionic bonding, and metallic bonding do not account for the high surface tension observed in water. London dispersion forces are relatively weaker intermolecular forces, while ionic and metallic bonding are types of intramolecular forces that do not directly contribute to the surface tension of water.

3. Which element is used in fluorescent lamps and emits ultraviolet light when excited?

• A. Mercury
• B. Neon
• C. Argon
• D. Krypton

Correct answer: A

Rationale: Mercury is the correct element used in fluorescent lamps to emit ultraviolet light when excited. When an electric current passes through the mercury vapor inside the lamp, it generates ultraviolet (UV) light. This UV light then excites the phosphors coated on the inner surface of the lamp, causing them to emit visible light. Neon, argon, and krypton are not commonly used in fluorescent lamps for this purpose. Neon is primarily used in neon signs, argon is used in incandescent and fluorescent bulbs for inertia gas, and krypton is mainly used in certain types of specialized light bulbs for its specific properties.

4. What is the term for the process of exchanging gases (oxygen and carbon dioxide) between the blood and the tissues?

• A. Inhalation
• B. Exhalation
• C. External respiration
• D. Internal respiration

Correct answer: C

Rationale: External respiration is the correct term for the process of exchanging gases (oxygen and carbon dioxide) between the blood and the tissues. It specifically refers to the exchange of gases that occurs in the lungs, where oxygen is absorbed into the bloodstream and carbon dioxide is released from the bloodstream to be exhaled. Inhalation and exhalation, choices A and B, are phases of the breathing process that involve the intake and expulsion of air into and out of the lungs, respectively. Internal respiration, choice D, is the process of gas exchange that happens at the cellular level between the blood and body tissues, not between the blood and the lungs or tissues as in external respiration. Therefore, external respiration is the most appropriate term for the described gas exchange process in the question.

5. What is the primary function of the cardiovascular system?

• A. To transport oxygen and nutrients
• B. To regulate blood pressure
• C. To digest food
• D. To filter waste products

Correct answer: A

Rationale: The primary function of the cardiovascular system is indeed to transport oxygen and nutrients to various tissues in the body. Choice B, 'To regulate blood pressure,' is incorrect as blood pressure regulation is one of the functions of the cardiovascular system but not its primary function. Choice C, 'To digest food,' is incorrect as digestion is primarily a function of the digestive system, not the cardiovascular system. Choice D, 'To filter waste products,' is incorrect as waste product filtration is primarily carried out by the kidneys and liver, not the cardiovascular system.

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