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. What is the basic unit of communication in the nervous system?

• A. Neuron
• B. Astrocyte
• C. Neurotransmitter
• D. Synapse

Correct answer: A

Rationale: A neuron is the basic unit of communication in the nervous system. Neurons are specialized cells responsible for transmitting information through electrical and chemical signals. Astrocytes are a type of glial cell that provide support and nourishment to neurons but do not participate in signal transmission. Neurotransmitters are chemicals that facilitate signal transmission between neurons, and synapses are the specific junctions where these signals are transmitted. Therefore, the correct answer is 'A: Neuron' as it is the primary cell involved in transmitting information in the nervous system.

3. Which of the following is responsible for maintaining the body's circadian rhythm?

• A. Thyroid gland
• B. Pineal gland
• C. Pancreas
• D. Hypothalamus

Correct answer: B

Rationale: The pineal gland is responsible for maintaining the body's circadian rhythm by producing melatonin. Melatonin is a hormone that helps regulate the sleep-wake cycle and is essential in controlling the body's internal clock. The thyroid gland, although important for metabolism, is not directly involved in regulating circadian rhythms. The pancreas plays a role in blood sugar regulation through insulin production, not in controlling circadian rhythms. The hypothalamus is involved in regulating various bodily functions, but the pineal gland is specifically responsible for the circadian rhythm.

4. What is the unit of measurement for density?

• A. Grams per liter (g/L)
• B. Kilograms per cubic meter (kg/m³)
• C. Pounds per square inch (psi)
• D. Newtons per meter (N/m)

Correct answer: A

Rationale: Density is defined as mass per unit volume. The most commonly used unit for density in the metric system is grams per liter (g/L). Kilograms per cubic meter (kg/m³) is also a common unit for density, but grams per liter is more frequently used in everyday measurements. Pounds per square inch (psi) is a unit of pressure, not density. Newtons per meter (N/m) is a unit of force per unit length, not density.

5. Sebaceous glands, located in the dermis, secrete an oily substance called:

• A. Sweat
• B. Sebum
• C. Cerumen
• D. Mucus

Correct answer: B

Rationale: Sebaceous glands are responsible for secreting an oily substance called sebum, not sweat, cerumen, or mucus. Sebum plays a vital role in lubricating and waterproofing the skin and hair, preventing them from drying out. Sweat glands produce sweat to regulate body temperature. Cerumen is the medical term for earwax, produced by ceruminous glands in the ear canal, while mucus is a slimy substance that protects and lubricates body tissues. Therefore, the correct answer is B: Sebum, as it is the oily substance secreted by sebaceous glands.

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