Nursing Elites

1. Which structure in the eye is responsible for detecting light?

• A. Cornea
• B. Retina
• C. Lens
• D. Iris

Correct answer: B

Rationale: The retina is the correct answer as it is the light-sensitive structure in the eye that detects light and converts it into signals for the brain to process visual information. The cornea is the transparent outer covering of the eye that helps to focus incoming light onto the lens. The lens further focuses the light onto the retina, which is where the actual light detection and signal conversion occur. The iris, on the other hand, controls the amount of light entering the eye by adjusting the size of the pupil but is not directly responsible for detecting light.

2. Why can optical fibers transmit light signals around bends?

• A. Reflection
• B. Refraction
• C. Diffraction
• D. Polarization

Correct answer: B

Rationale: Optical fibers can transmit light signals around bends primarily due to refraction. Refraction is the bending of light as it passes from one medium to another, such as from air to glass in an optical fiber. This bending allows the light signals to travel through the fiber even around bends, making optical fibers an efficient means of transmitting light signals over long distances. Reflection (Choice A) occurs when light bounces off a surface, which is not the primary mechanism allowing light to travel around bends in optical fibers. Diffraction (Choice C) refers to the bending of light waves around obstacles or openings, but it is not the main reason light signals can traverse bends in optical fibers. Polarization (Choice D) is the orientation of light waves in a specific plane, but it does not play a significant role in enabling light to navigate bends in optical fibers.

3. Which division of the nervous system is responsible for the 'fight or flight' response, preparing the body to respond to stressful situations?

• A. Somatic nervous system
• B. Autonomic nervous system
• C. Peripheral nervous system
• D. Central nervous system

Correct answer: B

Rationale: The autonomic nervous system is correctly identified as the division responsible for the 'fight or flight' response, which readies the body to react to stressful situations. This system regulates involuntary bodily functions, such as heart rate, pupil dilation, and adrenaline release during stress. The somatic nervous system controls voluntary movements and skeletal muscle activity, not the automatic responses seen in the 'fight or flight' reaction. The peripheral nervous system connects the central nervous system to the body's organs and limbs, facilitating communication, while the central nervous system, comprising the brain and spinal cord, serves as the primary control center of the body, integrating and processing information.

4. Which structure in the digestive system absorbs the most nutrients?

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

Correct answer: B

Rationale: The small intestine is the primary site where the absorption of nutrients from digested food occurs. Its large surface area, specialized cells, and villi play key roles in maximizing nutrient absorption, making it the structure in the digestive system that absorbs the most nutrients. The stomach's main function is to break down food with acid and enzymes, not absorb nutrients. The large intestine primarily absorbs water and electrolytes, not nutrients. The esophagus is a muscular tube that connects the throat with the stomach and does not play a role in nutrient absorption.

5. Glial cells support and protect neurons within the central and peripheral nervous system. What are they called?

• A. Astrocytes
• B. Neuroglia
• C. Oligodendrocytes
• D. Schwann cells

Correct answer: A

Rationale: Astrocytes are a type of glial cell that provide support and protection for neurons in both the central and peripheral nervous systems. While the term 'Neuroglia' is often used to refer to glial cells collectively, in this context, the question specifically asks for the name of the cells, making 'Astrocytes' the correct answer. Choice B, 'Neuroglia,' is a general term for all glial cells, not a specific type. Choices C and D, 'Oligodendrocytes' and 'Schwann cells,' are also types of glial cells but are not the primary cells responsible for supporting and protecting neurons as described in the question.

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