Nursing Elites

1. Which of the following is an example of a polymer?

• A. Methane
• B. Ethanol
• C. Polyethylene
• D. Acetic acid

Correct answer: C

Rationale: The correct answer is C, Polyethylene. Polyethylene is a polymer composed of a large number of repeating ethylene units linked together, forming a long-chain molecule, characteristic of polymers. Methane, ethanol, and acetic acid are small organic molecules that do not demonstrate the repeating unit structure typical of polymers. Therefore, they are not examples of polymers.

2. Which type of joint allows for the most movement?

• A. Ball-and-socket joint (shoulder)
• B. Hinge joint (elbow)
• C. Fibrocartilaginous joint (wrists)
• D. Suture joint (skull)

Correct answer: A

Rationale: A ball-and-socket joint allows for the most movement among the options provided. This type of joint is characterized by a rounded end of one bone fitting into a cup-like socket of another bone, allowing for a wide range of motion in multiple directions. The shoulder joint is a prime example of a ball-and-socket joint, enabling movements such as flexion, extension, abduction, adduction, and rotation. In contrast, a hinge joint (option B) like the elbow primarily allows for movement in one plane (flexion and extension). Fibrocartilaginous joints (option C) like the wrists have limited movement due to the presence of cartilage between the bones. Suture joints (option D) in the skull are immovable joints that provide structural support but do not allow for significant movement.

3. The hypothalamus, a part of the brain, plays a crucial role in endocrine regulation. It secretes GnRH (Gonadotropin-releasing hormone) which stimulates the pituitary gland to produce FSH and LH. What is the MAIN function of FSH and LH?

• A. Regulate blood sugar levels
• B. Control growth and development
• C. Stimulate the fight-or-flight response
• D. Maintain calcium homeostasis

Correct answer: B

Rationale: FSH (Follicle-stimulating hormone) and LH (Luteinizing hormone) are hormones produced by the pituitary gland in response to GnRH from the hypothalamus. FSH plays a key role in the growth and development of ovarian follicles in females and sperm production in males. LH is essential for the maturation of the ovarian follicle, ovulation, and the formation of the corpus luteum in females, as well as the production of testosterone in males. Therefore, the main function of FSH and LH is to control growth and development in the reproductive system. Choices A, C, and D are incorrect as they do not align with the roles of FSH and LH in reproductive physiology. Regulating blood sugar levels is primarily the function of insulin and glucagon, controlling the fight-or-flight response involves hormones like adrenaline and noradrenaline, and maintaining calcium homeostasis is mainly regulated by parathyroid hormone and calcitonin.

4. What type of nuclear force is responsible for holding protons and neutrons together in the nucleus of an atom?

• A. Electromagnetism
• B. Gravity
• C. Strong nuclear force
• D. Weak nuclear force

Correct answer: C

Rationale: The correct answer is the strong nuclear force. It is an incredibly powerful force that overcomes the repulsive electrostatic force between protons, binding them together and stabilizing the nucleus. The strong nuclear force is essential for maintaining the integrity and stability of an atom's nucleus. Electromagnetism (Choice A) is responsible for interactions between charged particles but is not the primary force holding the nucleus together. Gravity (Choice B) is a very weak force at the nuclear level and is not responsible for binding protons and neutrons in the nucleus. The weak nuclear force (Choice D) is involved in certain types of radioactive decay processes, but it is not the force responsible for holding the nucleus together.

5. How is blood pressure controlled by the body?

• A. By adjusting heart rate only
• B. By regulating blood volume
• C. By baroreceptors and hormones
• D. By adjusting body temperature

Correct answer: C

Rationale: Blood pressure is controlled by baroreceptors located in the aortic arch and carotid arteries that detect changes in blood pressure levels. When blood pressure is high, these receptors signal for adjustments to lower it. Additionally, hormones such as renin from the kidneys are released when blood pressure drops, further aiding in blood pressure regulation. Choice A is incorrect because blood pressure regulation involves more than just adjusting heart rate; it also includes vasodilation and vasoconstriction. Choice B is incorrect as while blood volume can impact blood pressure, it is not the primary mechanism of blood pressure control. Choice D is incorrect as body temperature regulation is a separate physiological process and not directly related to blood pressure control.

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