Nursing Elites

1. What is the myelin sheath and what does it do?

• A. A group of nerve cells that perform a specific function.
• B. A fatty substance that insulates some nerve fibers.
• C. A fluid-filled cavity within the brain.
• D. The junction between two neurons.

Correct answer: B

Rationale: The myelin sheath is a fatty substance that insulates some nerve fibers. It is made up of specialized cells that wrap around the axons of neurons, providing insulation and speeding up the transmission of nerve impulses. Choice A is incorrect as the myelin sheath is not a group of nerve cells but rather a substance that surrounds nerve fibers. Choice C is incorrect as the myelin sheath is not a fluid-filled cavity within the brain. Choice D is incorrect as the myelin sheath is not the junction between two neurons.

2. Which property of a wave determines its energy?

• A. Wavelength
• B. Amplitude
• C. Frequency
• D. Velocity

Correct answer: B

Rationale: The energy of a wave is determined by its amplitude, which is the measure of its maximum displacement from the equilibrium position. Waves with higher amplitudes carry more energy as energy is directly proportional to amplitude. Therefore, the correct answer is B) Amplitude. Choice A (Wavelength) does not determine the energy of a wave; it is related to the spatial length between wave crests. Choice C (Frequency) is not the property that determines a wave's energy; it refers to the number of complete oscillations a wave undergoes in a given time. Choice D (Velocity) is the speed at which a wave propagates through a medium and is not directly related to its energy.

3. Which valve prevents the return of blood into the right ventricle?

• A. Pulmonary semilunar valve
• B. Aortic semilunar valve
• C. Tricuspid valve
• D. Mitral valve

Correct answer: A

Rationale: The correct answer is A: Pulmonary semilunar valve. The pulmonary semilunar valve is located between the right ventricle and the pulmonary artery. It opens to allow blood to be pumped into the pulmonary artery but closes to prevent blood from returning back into the right ventricle. The aortic semilunar valve is located between the left ventricle and the aorta. The tricuspid valve is located between the right atrium and right ventricle, and the mitral valve is located between the left atrium and left ventricle. Therefore, the pulmonary semilunar valve is the specific valve responsible for preventing the backflow of blood into the right ventricle during the cardiac cycle.

4. Which of these organisms belongs to the kingdom Protista?

• A. Coral
• B. Yeast
• C. Euglena
• D. Mushroom

Correct answer: C

Rationale: A) Coral belongs to the kingdom Animalia, specifically in the phylum Cnidaria. B) Yeast belongs to the kingdom Fungi. C) Euglena is a unicellular organism that belongs to the kingdom Protista. It is a type of protist that has characteristics of both plants and animals. D) Mushroom belongs to the kingdom Fungi. Therefore, among the options provided, only Euglena belongs to the kingdom Protista.

5. Which organ produces bile to aid in digestion?

• A. Pancreas
• B. Liver
• C. Gallbladder
• D. Stomach

Correct answer: B

Rationale: The correct answer is B: Liver. The liver produces bile, which is stored in the gallbladder and released into the small intestine to aid in the digestion and absorption of fats. The pancreas secretes digestive enzymes, not bile. The gallbladder stores bile but does not produce it. The stomach produces gastric juices, not bile, to aid in digestion.

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