Nursing Elites

1. What is the primary function of the heart in the circulatory system?

• A. To filter blood
• B. To pump blood throughout the body
• C. To absorb oxygen
• D. To remove carbon dioxide

Correct answer: B

Rationale: The correct answer is B: 'To pump blood throughout the body.' The primary function of the heart in the circulatory system is to pump blood, which carries oxygen and nutrients, throughout the body. Choice A, 'To filter blood,' is incorrect as the heart does not filter blood; that is primarily done by the kidneys. Choice C, 'To absorb oxygen,' is incorrect as the lungs are responsible for oxygen absorption. Choice D, 'To remove carbon dioxide,' is incorrect as the lungs facilitate the removal of carbon dioxide from the body.

2. What is the role of the mitochondria in the cell?

• A. Protein synthesis
• B. Energy production
• C. Breaking down waste
• D. Cell division

Correct answer: B

Rationale: The correct answer is B: Energy production. Mitochondria are known as the powerhouses of the cell because they generate adenosine triphosphate (ATP) through the process of cellular respiration. ATP is a molecule that stores and releases energy, providing the cell with the necessary energy for various activities and functions. Choices A, C, and D are incorrect. Protein synthesis primarily occurs in the ribosomes, breaking down waste is mainly carried out by lysosomes, and cell division is orchestrated by the nucleus and other organelles like the centrioles.

3. Which structure in the ear is responsible for balance?

• A. Cochlea
• B. Semicircular canals
• C. Ossicles
• D. Eustachian tube

Correct answer: B

Rationale: The semicircular canals in the inner ear are responsible for maintaining balance by detecting changes in head position and movement. These structures contain fluid and hair cells that send signals to the brain regarding the body's orientation in space, helping us stay balanced and navigate our surroundings. The cochlea is responsible for hearing, the ossicles are involved in sound transmission, and the Eustachian tube helps equalize pressure in the middle ear, but they are not directly related to balance.

4. Which hormone regulates the sleep-wake cycle?

• A. Melatonin
• B. Insulin
• C. Cortisol
• D. Thyroxine

Correct answer: A

Rationale: Melatonin, produced by the pineal gland, is the hormone that regulates the sleep-wake cycle. Its secretion is influenced by light exposure, with levels typically rising in the evening to promote sleep and falling in the morning to encourage wakefulness. Insulin is involved in regulating blood sugar levels, not the sleep-wake cycle. Cortisol plays a role in the body's stress response and circadian rhythm but is not the primary hormone regulating sleep-wake cycles. Thyroxine is a hormone produced by the thyroid gland that regulates metabolism, not the sleep-wake cycle.

5. You have been given a sample tissue that has pillar-shaped cells arranged tightly together. The tissue you have is:

• A. Squamous Epithelium
• B. Cuboidal Epithelium
• C. Columnar Epithelium
• D. Transitional Epithelium

Correct answer: C

Rationale: The correct answer is C: Columnar Epithelium. Columnar epithelium is characterized by tall, pillar-like cells that are closely packed together. This arrangement allows for absorption and secretion in tissues like the digestive tract, where this type of epithelium is commonly found. Squamous epithelium (choice A) consists of flat cells, cuboidal epithelium (choice B) has cube-shaped cells, and transitional epithelium (choice D) is found in areas that need to stretch and expand, like the urinary bladder.

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