Nursing Elites

1. Which of the following macromolecules will always contain nitrogen?

• A. Fatty acids
• B. Proteins
• C. Lipids
• D. Carbohydrates

Correct answer: B

Rationale: The correct answer is B: Proteins. Proteins are the only macromolecules that always contain nitrogen in their amino acid structure. Nitrogen is a key element found in the amino groups of amino acids, which are the building blocks of proteins. Fatty acids (Choice A), lipids (Choice C), and carbohydrates (Choice D) do not always contain nitrogen in their structure. Fatty acids are composed of long hydrocarbon chains and do not contain nitrogen. Lipids consist mainly of carbon, hydrogen, and oxygen, with some classes of lipids containing phosphorus but not nitrogen. Carbohydrates are made up of carbon, hydrogen, and oxygen, forming structures like sugars and starches, but they do not contain nitrogen.

2. In the context of cholesterol levels, LDL cholesterol is often referred to as:

• A. HDL or "good" cholesterol.
• B. LDL or "bad" cholesterol.
• C. Total cholesterol, encompassing both LDL and HDL.
• D. VLDL, a type of triglyceride transported in the bloodstream.

Correct answer: B

Rationale: LDL cholesterol is often referred to as "bad" cholesterol because high levels of LDL can lead to plaque buildup in the arteries, increasing the risk of heart disease and stroke. LDL cholesterol is considered harmful as it contributes to the formation of plaque in blood vessels, whereas HDL cholesterol helps remove LDL from the arteries. Choice A is incorrect because HDL is known as "good" cholesterol, which helps remove LDL cholesterol from the bloodstream. Choice C is incorrect as it refers to total cholesterol, which includes LDL, HDL, and other lipids. Choice D is incorrect as VLDL is a different type of lipoprotein that carries triglycerides and is not specifically related to LDL cholesterol.

3. Which of the following nerves has the longest axon in the human body?

• A. Dorsal root ganglion
• B. Laryngeal nerve
• C. Sciatic nerve
• D. None of the above

Correct answer: C

Rationale: The sciatic nerve contains the longest axon in the human body, extending from the lower back down the leg. This nerve is responsible for innervating the muscles of the lower limb. The dorsal root ganglion and laryngeal nerve do not possess axons as long as the sciatic nerve, making them incorrect choices. Therefore, the correct answer is C, the sciatic nerve.

4. What is the main component that gives bones their rigidity and hardness?

• A. Collagen
• B. Calcium phosphate
• C. Cartilage
• D. Ligaments

Correct answer: B

Rationale: Calcium phosphate is the main component that gives bones their rigidity and hardness. It combines with calcium hydroxide to form hydroxyapatite crystals, which provide strength and structure to bones. Collagen, on the other hand, provides flexibility and tensile strength. Cartilage is a type of connective tissue found in joints, and ligaments are fibrous tissues that connect bones to other bones, but they do not contribute to the rigidity and hardness of bones.

5. Which component of the nervous system is responsible for controlling voluntary movements, such as the contraction of skeletal muscles?

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

Correct answer: C

Rationale: The correct answer is C: Somatic nervous system. The somatic nervous system is responsible for controlling voluntary movements, such as the contraction of skeletal muscles. This system consists of motor neurons that send signals from the central nervous system to the skeletal muscles, allowing for conscious control over movement. The autonomic nervous system (A) controls involuntary functions like heart rate and digestion, the peripheral nervous system (B) includes all nerves outside the central nervous system, and the sympathetic nervous system (D) is a division of the autonomic nervous system responsible for the fight-or-flight response. Therefore, choices A, B, and D are incorrect as they do not specifically regulate voluntary movements of skeletal muscles, which is a function of the somatic nervous system.

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