Nursing Elites

1. Which structure helps regulate body temperature by constricting or dilating in response to temperature changes?

• A. Sebaceous glands
• B. Hair follicles
• C. Sweat glands
• D. Langerhans cells

Correct answer: C

Rationale: Sweat glands play a crucial role in regulating body temperature by producing sweat that evaporates from the skin surface. This evaporation cools the body when it is hot and helps to maintain a stable internal temperature. Sebaceous glands produce oil to lubricate the skin, hair follicles are responsible for hair growth, and Langerhans cells are a type of immune cell in the skin. Therefore, the correct answer is 'Sweat glands' as they are specifically designed to respond to temperature changes by constricting or dilating to help regulate body temperature.

2. What determines the magnitude of the frictional force acting on a book sliding across a table?

• A. Only the mass of the book
• B. Only the normal force from the table
• C. Both the mass of the book and the normal force from the table
• D. Neither the mass of the book nor the normal force from the table

Correct answer: C

Rationale: The magnitude of the frictional force acting on the book sliding across a table is determined by both the mass of the book and the normal force from the table. Frictional force is proportional to the normal force (which is influenced by the weight of the book, i.e., its mass) and is affected by the surfaces in contact and other friction-related factors. Therefore, both the mass of the book and the normal force from the table are essential in determining the frictional force experienced by the book during its sliding motion. Choices A, B, and D are incorrect because friction is a result of the interaction between the surfaces and is influenced by both the mass of the object and the normal force acting on it.

3. What is the main function of valence electrons in chemical bonding?

• A. They are responsible for holding the nucleus together.
• B. They are involved in forming bonds with other atoms.
• C. They determine the element's physical properties.
• D. They play no role in chemical reactions.

Correct answer: B

Rationale: Valence electrons are the electrons in the outermost energy level of an atom. These electrons are involved in forming bonds with other atoms, which is crucial for chemical bonding. By participating in bonding, valence electrons determine an atom's ability to form compounds and engage in chemical reactions. Therefore, the primary function of valence electrons is to facilitate the formation of bonds between atoms, making option B the correct answer. Choices A, C, and D are incorrect because valence electrons primarily influence chemical bonding by participating in the formation of bonds between atoms, rather than holding the nucleus together, determining physical properties, or having no role in chemical reactions.

4. Which organ serves as the human body's command center, integrating sensory information and coordinating movement and vital functions?

• A. Lungs
• B. Brain
• C. Kidneys
• D. Stomach

Correct answer: B

Rationale: The brain is the human body's command center, responsible for integrating sensory information, coordinating movement, and regulating vital functions such as breathing, heart rate, and digestion. While the lungs, kidneys, and stomach perform crucial functions in the body, they do not have the central role of serving as the command center for these essential bodily processes. The lungs are primarily involved in respiration, the kidneys in filtering blood and regulating fluid balance, and the stomach in digestion. However, none of these organs have the comprehensive control over sensory integration, movement coordination, and vital functions like the brain does.

5. What are fingernails and toenails primarily made of?

• A. Collagen (Collagen is found in the dermis)
• B. Keratin
• C. Melanin (Melanin provides pigment, not structure)
• D. Sebum (Sebum is an oily substance)

Correct answer: B

Rationale: Fingernails and toenails are primarily made of a protein called keratin. Keratin is a tough, fibrous protein that provides structure and strength to nails, hair, and the outer layer of skin. Collagen, as mentioned, is found in the dermis and is not the primary component of nails. Melanin provides pigment to the skin and hair, not the structure of nails. Sebum is an oily substance produced by the skin's sebaceous glands and is not a structural component of nails.

Similar Questions