Nursing Elites

1. What is hydroxyapatite?

• A. A mixture of minerals such as calcium and phosphorus that strengthen the collagen matrix of bone.
• B. The structural unit of a bone that runs the length of the bone.
• C. The covering of bones at the point of articulation to prevent grinding.
• D. The lightest portion of a long bone and concentrated at the ends.

Correct answer: A

Rationale: Hydroxyapatite is a mineral compound composed of calcium and phosphorus that plays a crucial role in strengthening the collagen matrix of bones, contributing to their structural integrity and hardness. It is a key component of bone tissue and provides the mineralization necessary for bone strength and density. Choice B is incorrect because the structural unit of a bone is the osteon or Haversian system, not hydroxyapatite. Choice C is incorrect as it describes cartilage, not hydroxyapatite. Choice D is incorrect as it refers to the epiphysis, which is not synonymous with hydroxyapatite.

2. Which gland, often referred to as the 'master gland' of the endocrine system and located at the base of the brain, secretes various hormones that control other glands?

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

Correct answer: B

Rationale: The pituitary gland is correctly known as the 'master gland' of the endocrine system. It is situated at the base of the brain and plays a crucial role in secreting a variety of hormones that regulate the functions of other endocrine glands in the body. These hormones control growth, metabolism, reproduction, and various other essential bodily functions. The other choices, thyroid gland, adrenal gland, and pancreas, are incorrect as they do not serve as the 'master gland' of the endocrine system nor are located at the base of the brain like the pituitary gland.

3. What controls muscles by sending electrical impulses to the muscles?

• A. Blood vessels
• B. Nerves
• C. Hormones
• D. Neurons

Correct answer: B

Rationale: Nerves control muscles by transmitting electrical impulses that initiate muscle contractions. Blood vessels are responsible for transporting blood, not controlling muscles. Hormones are chemical messengers produced by glands to regulate bodily functions, not specifically controlling muscles. Neurons are the basic building blocks of the nervous system that transmit signals, but nerves are the specific structures that control muscles by sending electrical impulses.

4. A ball is rolling across the floor and comes to a stop on its own. What force caused the ball to stop?

• A. Gravitational force
• B. Normal force from the floor
• C. Air resistance
• D. None of the above

Correct answer: C

Rationale: The force that caused the ball to stop rolling across the floor is air resistance. As the ball moves through the air, air resistance acts in the opposite direction of its motion, gradually slowing it down until it comes to a stop. In this scenario, the ball is not in contact with the floor, so the normal force from the floor does not play a role in stopping the ball. Gravitational force acts to pull objects towards the center of the Earth and would not directly stop the ball in this situation. Therefore, air resistance is the force that opposes the motion of the rolling ball and causes it to come to a stop.

5. An atom has 2 protons, 4 neutrons, and 2 electrons. What is the approximate atomic mass of this atom?

• A. 2
• B. 4
• C. 6
• D. 8

Correct answer: D

Rationale: The atomic mass of an atom is the sum of the protons and neutrons in its nucleus. In this case, the atom has 2 protons and 4 neutrons, totaling 6 particles in the nucleus. Therefore, the approximate atomic mass of this atom is 6, making choice C incorrect. The number of electrons does not significantly contribute to the atomic mass, as they are much lighter and located in the electron cloud surrounding the nucleus. Choices A, B, and C are incorrect as they do not reflect the correct calculation of atomic mass based on protons and neutrons only.

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