Nursing Elites

1. Which of the following neurotransmitters slows down the activity of neurons to prevent overexcitation?

• A. Acetylcholine
• B. Dopamine
• C. GABA
• D. Serotonin

Correct answer: C

Rationale: The correct answer is C: GABA (gamma-aminobutyric acid). GABA is an inhibitory neurotransmitter that slows down neuronal activity, helping to prevent overexcitation in the brain. It counterbalances the effects of excitatory neurotransmitters like glutamate, playing a crucial role in maintaining the balance of neuronal activity in the brain. Acetylcholine (Choice A) is primarily an excitatory neurotransmitter involved in muscle movement and cognitive functions. Dopamine (Choice B) plays a role in reward-motivated behavior and motor control. Serotonin (Choice D) is involved in regulating mood, appetite, and sleep but is not primarily responsible for slowing down neuronal activity to prevent overexcitation.

2. Which property of a substance describes how much matter is packed into a given space?

• A. Mass
• B. Volume
• C. Weight
• D. Density

Correct answer: D

Rationale: Density is the property of a substance that describes how much matter is packed into a given space. It is calculated by dividing the mass of the substance by its volume. Mass refers to the amount of matter in an object, volume is the amount of space an object occupies, and weight is the force of gravity acting on an object's mass. Density specifically relates to how tightly packed the particles of a substance are. In this context, density is the most appropriate answer as it directly addresses how matter is packed into a given space. Mass and weight are related to the quantity of matter and the force of gravity, respectively, but do not directly describe the compactness of matter in a given space. Volume, on the other hand, refers to the space occupied by an object, not the amount of matter packed into that space.

3. What is the purpose of a catalyst?

• A. To increase a reaction rate by increasing the activation energy
• B. To increase a reaction rate by increasing the temperature
• C. To increase a reaction rate by decreasing the activation energy
• D. To increase a reaction rate by decreasing the temperature

Correct answer: C

Rationale: The purpose of a catalyst is to increase a reaction's rate by decreasing the activation energy required for the reaction to occur. This allows the reaction to proceed more quickly without being consumed in the process. The catalyst provides an alternate mechanism with a lower activation energy, making it easier for the reactants to convert into products. Choice A is incorrect because a catalyst lowers, not increases, the activation energy. Choice B is incorrect because a catalyst does not affect the temperature directly but provides an alternative pathway for the reaction to occur more easily. Choice D is incorrect because a catalyst does not lower the temperature but facilitates the reaction by lowering the activation energy barrier. Therefore, the correct answer is C, 'To increase a reaction rate by decreasing the activation energy.'

4. How does ingested food move through the digestive tract?

• A. Chewing, digestion, absorption
• B. Swallowing, peristalsis, segmentation
• C. Swallowing, mastication, defecation
• D. Digestion, absorption, excretion

Correct answer: B

Rationale: The correct answer is B: Swallowing, peristalsis, segmentation. Food moves through the digestive tract by first being swallowed, then undergoing peristalsis (wave-like movements that propel food along the digestive tract), and finally undergoing segmentation (mixing movements in the intestines). Chewing and digestion occur in the mouth and stomach, respectively, while absorption and excretion happen later in the digestive process. Choice A is incorrect as absorption is a later stage in the process. Choice C is incorrect because defecation is the elimination of waste, not the movement of food. Choice D is incorrect as excretion is the elimination of waste products, not the movement of ingested food through the digestive tract.

5. Which of the following is NOT a common location for lymph nodes?

• A. Groin
• B. Armpit
• C. Neck
• D. Liver

Correct answer: D

Rationale: The correct answer is 'D: Liver.' The liver is not a common location for lymph nodes. Lymph nodes are small, bean-shaped structures distributed throughout the body, including common sites like the groin, armpit, and neck. They play a crucial role in the immune system by filtering lymph fluid and trapping harmful substances, aiding the body in defending against infections and diseases. The liver, on the other hand, is an organ responsible for various functions like detoxification, metabolism, and storage, but it does not house lymph nodes.

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