Nursing Elites

1. Which valve prevents blood from entering the left atrium when the ventricles contract?

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

Correct answer: C

Rationale: The correct answer is the mitral valve, also known as the bicuspid valve. The mitral valve prevents blood from flowing back into the left atrium during ventricular contraction. The tricuspid valve is located between the right atrium and right ventricle, the pulmonary valve is between the right ventricle and the pulmonary artery, and the aortic valve is situated between the left ventricle and the aorta. Therefore, choices A, B, and D are incorrect as they are not related to preventing blood from entering the left atrium during ventricular contraction.

2. Where does most of the chemical digestion and absorption of nutrients occur?

• A. Mouth
• B. Stomach
• C. Small intestine
• D. Large intestine

Correct answer: C

Rationale: The small intestine is the primary site for both chemical digestion and absorption of nutrients in the digestive system. The lining of the small intestine is equipped with villi and microvilli, which significantly increase the surface area available for absorption. Enzymes from the pancreas and bile from the liver play crucial roles in further breaking down food into absorbable molecules that can pass through the intestinal wall into the bloodstream. While the stomach assists in mechanical breakdown and initial protein digestion, it is not the main site of nutrient absorption. The large intestine, on the other hand, mainly absorbs water and electrolytes from undigested food particles. The mouth aids in initial mechanical breakdown and some carbohydrate digestion, but the majority of nutrient absorption occurs in the small intestine, making it the correct answer.

3. What does the term 'colligative property' refer to in solutions?

• A. Properties that depend on the nature of the solute particles
• B. Properties that depend on the concentration of solute particles
• C. Properties that depend on the temperature of the solution
• D. Properties that depend on the pressure of the solution

Correct answer: B

Rationale: Colligative properties are properties of a solution that depend on the concentration of solute particles, regardless of the identity of the solute. These properties include lowering the vapor pressure, elevation of boiling point, depression of freezing point, and osmotic pressure. The concentration of solute particles affects these properties, not the nature, temperature, or pressure of the solution. Therefore, choice B is the correct answer as it accurately reflects the definition of colligative properties. Choices A, C, and D are incorrect because colligative properties are not based on the nature, temperature, or pressure of the solute, but rather on the concentration of solute particles in the solution.

4. Which statement is true regarding aromatic compounds?

• A. Contain a ring structure with alternating single and double bonds
• B. Readily undergo addition reactions
• C. Are easily broken down by water
• D. Do not contain any pi (π) bonds

Correct answer: A

Rationale: Aromatic compounds contain a ring structure with alternating single and double bonds, known as a benzene ring. This alternating pattern of bonds gives aromatic compounds their stability and unique properties. Due to this resonance, aromatic compounds are less reactive towards addition reactions. Water does not easily break down aromatic compounds due to their stability from the delocalized electrons in the ring structure. Therefore, the correct statement is that aromatic compounds contain a ring structure with alternating single and double bonds, providing them with stability and unique properties. Choices B, C, and D are incorrect. Aromatic compounds do not readily undergo addition reactions (B), are not easily broken down by water (C), and do contain pi (π) bonds due to the presence of the alternating single and double bonds in the ring structure (D).

5. Electroencephalography (EEG) measures electrical activity in the brain, primarily reflecting the activity of:

• A. Neurons
• B. Astrocytes
• C. Oligodendrocytes
• D. Microglia

Correct answer: A

Rationale: EEG measures electrical activity in the brain, primarily reflecting the activity of neurons. Neurons are the primary cells responsible for generating electrical impulses and transmitting information in the brain. Astrocytes, oligodendrocytes, and microglia are other types of cells in the brain that have different functions and are not primarily involved in generating the electrical activity measured by EEG. Astrocytes support neuronal function, oligodendrocytes produce myelin to insulate axons, and microglia are involved in immune responses and maintaining brain health, but they do not generate the electrical impulses detected by EEG.

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