Nursing Elites

1. What is the process by which cells respond to external stimuli, such as chemicals, temperature, or touch, called?

• A. Signal transduction
• B. Homeostasis
• C. Adaptation
• D. Metabolism

Correct answer: A

Rationale: Signal transduction is the correct answer. It is the process by which cells respond to external stimuli like chemicals, temperature, or touch. When a cell receives a signal from its environment, it triggers a series of molecular events leading to a specific cellular response. This process involves transmitting signals from the cell surface to the interior, triggering various cellular activities. Homeostasis, on the other hand, refers to an organism's ability to maintain internal stability in response to external changes. Adaptation involves an organism adjusting to its environment over time through genetic changes or behavioral modifications, which is distinct from the process of cells responding to immediate external stimuli. Metabolism, although essential for cellular functions, is not specifically about cells responding to external stimuli but rather the biochemical processes involved in energy production, storage, and utilization within cells.

2. The 'fight-or-flight' response is triggered by the hormone released from the:

• A. Thyroid gland
• B. Adrenal glands
• C. Pituitary gland
• D. Pancreas

Correct answer: B

Rationale: The 'fight-or-flight' response is triggered by the release of adrenaline (epinephrine) and norepinephrine from the adrenal glands. These hormones prepare the body to either confront or flee from a perceived threat or stressor. The adrenal glands are crucial in initiating this rapid physiological response. Choices A, C, and D are incorrect because the thyroid gland primarily regulates metabolism and energy levels, the pituitary gland controls other endocrine glands but does not directly trigger the 'fight-or-flight' response, and the pancreas is responsible for regulating blood sugar levels through insulin and glucagon, not for triggering the 'fight-or-flight' response.

3. Which property of a substance resists a change in its shape?

• A. Density
• B. Mass
• C. Inertia
• D. Elasticity

Correct answer: D

Rationale: Elasticity refers to a material's ability to resist deformation and return to its original shape after stress is applied. It is the property that resists a change in shape. Density is the mass per unit volume of a substance. Mass is the amount of matter in an object, while inertia is the tendency of an object to resist changes in its state of motion. Viscosity, not mentioned in the question, is the resistance of a fluid to flow, not shape change.

4. Which of the following is the main organ responsible for absorbing nutrients?

• A. Stomach
• B. Small intestine
• C. Large intestine
• D. Pancreas

Correct answer: B

Rationale: The small intestine is the main organ responsible for absorbing nutrients from the food we eat. It is where the majority of digestion and absorption of nutrients such as carbohydrates, proteins, fats, vitamins, and minerals occurs. The inner lining of the small intestine is covered in tiny finger-like projections called villi, which increase the surface area available for nutrient absorption. While the stomach plays a role in breaking down food into smaller particles, the actual absorption of nutrients primarily takes place in the small intestine. The large intestine mainly absorbs water and electrolytes, and the pancreas produces digestive enzymes and hormones but is not primarily responsible for absorbing nutrients.

5. Which type of immune cell does the human immunodeficiency virus (HIV) target and destroy?

• A. Neutrophils
• B. Macrophages
• C. Helper T cells
• D. Memory B cells

Correct answer: C

Rationale: HIV targets and destroys Helper T cells, which are vital for coordinating the immune response against infections. The destruction of Helper T cells weakens the immune system, leading to acquired immunodeficiency syndrome (AIDS). Neutrophils (Choice A) are primarily involved in acute inflammatory responses and fighting bacterial infections. Macrophages (Choice B) play a role in phagocytosis and antigen presentation but are not the primary target of HIV. Memory B cells (Choice D) are responsible for mounting a quicker and more robust antibody response upon re-exposure to a pathogen, but they are not the main target of HIV infection.

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