Nursing Elites

1. Neurotransmitters send chemical messages across the gap between one neuron and another through which of the following structures?

• A. Schwann cell
• B. ganglion
• C. synapse
• D. axon

Correct answer: C

Rationale: Neurotransmitters send chemical messages across the gap between one neuron and another through a structure called the synapse. The synapse is a specialized junction where the axon of one neuron meets the dendrite or cell body of another neuron. Neurotransmitters are released from the axon terminal of the presynaptic neuron and travel across the synaptic cleft to bind to receptors on the postsynaptic neuron, transmitting the signal between the two neurons. Choice A, Schwann cell, is incorrect as Schwann cells are responsible for producing myelin sheath around axons in the peripheral nervous system, not for transmitting neurotransmitters between neurons. Choice B, ganglion, is incorrect as ganglia are clusters of nerve cell bodies outside the central nervous system and do not directly participate in the transmission of chemical messages between neurons. Choice D, axon, is incorrect as the axon is a long, slender projection of a neuron that conducts electrical impulses away from the cell body and towards the axon terminals, where neurotransmitters are released into the synapse, but it is not the structure across which neurotransmitters travel to communicate between neurons.

2. Which of the following functional groups is present in carboxylic acids?

• A. Carbonyl
• B. Hydroxyl
• C. Carboxyl
• D. Aldehyde

Correct answer: C

Rationale: Carboxylic acids contain the carboxyl functional group, which consists of a carbonyl group (C=O) and a hydroxyl group (-OH) attached to the same carbon atom. The carboxyl group is represented as -COOH in the molecular structure of carboxylic acids. Therefore, the correct functional group present in carboxylic acids is the carboxyl group, making option C the correct choice. Option A, 'Carbonyl,' is incorrect as it only refers to the C=O group without the -OH component present in carboxylic acids. Option B, 'Hydroxyl,' is incorrect as it only represents the -OH group without the carbonyl group. Option D, 'Aldehyde,' is incorrect as it refers to a different functional group with a carbonyl group attached to a hydrogen atom, not the carboxyl group found in carboxylic acids.

3. Which of the following is NOT an example of a homeostatic mechanism?

• A. Shivering when the body temperature falls.
• B. Increasing heart rate when blood pressure is low.
• C. Weight gain when consuming excess calories.
• D. Secreting insulin to decrease blood sugar concentration.

Correct answer: C

Rationale: Weight gain when consuming excess calories is not an example of a homeostatic mechanism. Homeostasis refers to the body's ability to maintain a stable internal environment despite external changes. The other options listed (A, B, and D) involve physiological responses aimed at restoring balance or stability within the body (e.g., regulating body temperature, blood pressure, and blood sugar levels). Shivering, increasing heart rate, and secreting insulin are mechanisms to counteract specific imbalances and maintain internal equilibrium. In contrast, weight gain due to excess calorie intake does not represent a specific regulatory mechanism but rather an outcome of energy imbalance. The body stores excess energy as fat rather than actively regulating a physiological parameter to restore balance.

4. Which muscle has involuntary cells that are branched and striated and connected by intercalated discs with gap junctions?

• A. Smooth muscle
• B. Cardiac muscle
• C. Skeletal muscle
• D. Epithelial muscle

Correct answer: B

Rationale: The correct answer is B: Cardiac muscle. Cardiac muscle cells fit the description provided in the question; they are involuntary, striated, and branched, with intercalated discs containing gap junctions that allow for synchronized contractions of the heart. Smooth muscle (choice A) lacks striations and is found in the walls of internal organs. Skeletal muscle (choice C) is voluntary and attaches to bones for movement. 'Epithelial muscle' (choice D) is not a valid muscle type, making it an incorrect choice.

5. Which brain area can lead to difficulty with language and speech if damaged?

• A. Broca's area
• B. Wernicke's area
• C. Occipital lobe
• D. Cerebellum

Correct answer: A

Rationale: Damage to Broca's area, located in the frontal lobe of the brain, can result in difficulties with language and speech production. Broca's area is responsible for speech production and coordinating the muscles involved in speech. Damage to this area can lead to Broca's aphasia, characterized by struggles in forming words and sentences. On the other hand, damage to Wernicke's area in the temporal lobe can cause issues with language comprehension and producing meaningful language, leading to Wernicke's aphasia. The occipital lobe primarily processes visual information, while the cerebellum is responsible for coordinating movement and balance, not language and speech.

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