Nursing Elites

1. The tiny contractile units within muscle cells are called:

• A. Myocytes
• B. Myofibrils
• C. Sarcomeres
• D. Tendons

Correct answer: C

Rationale: The correct answer is C: Sarcomeres. Sarcomeres are the basic contractile units within muscle cells. They are made up of overlapping filaments of actin and myosin proteins, which slide past each other during muscle contraction, resulting in muscle movement. Myocytes (A) are muscle cells, myofibrils (B) are cylindrical structures within muscle fibers composed of sarcomeres, and tendons (D) are tough bands of connective tissue that connect muscle to bone. Therefore, sarcomeres are specifically responsible for muscle contraction within muscle cells.

2. Which neurotransmitter is associated with mood, sleep, and memory?

• A. Dopamine
• B. Serotonin
• C. Acetylcholine
• D. Glutamate

Correct answer: B

Rationale: The correct answer is B: Serotonin. Serotonin is a neurotransmitter that plays a crucial role in regulating mood, sleep, and memory. It is known as the 'feel-good' neurotransmitter because it helps to promote feelings of well-being and happiness. Serotonin also contributes to the regulation of sleep patterns and plays a role in memory and learning processes. Dopamine is associated with reward and motivation, acetylcholine with muscle movement and cognitive functions, and glutamate with learning and memory as an excitatory neurotransmitter. Therefore, of the options provided, serotonin is the neurotransmitter most closely linked to mood, sleep, and memory.

3. Which hormone, produced by the adrenal glands, prepares the body for a "fight or flight" response by increasing heart rate, dilating airways, and mobilizing energy stores?

• A. Cortisol
• B. Aldosterone
• C. Epinephrine
• D. Insulin

Correct answer: c

Rationale: The correct answer is C: Epinephrine. Epinephrine, also known as adrenaline, is the hormone produced by the adrenal glands that prepares the body for a 'fight or flight' response. It increases heart rate to pump more blood to muscles, dilates airways to improve oxygen intake, and mobilizes energy stores to provide immediate fuel for physical activity. Cortisol is a hormone involved in stress response and metabolism regulation, but it does not directly trigger the rapid physiological changes associated with 'fight or flight.' Aldosterone regulates salt and water balance, while insulin regulates blood sugar levels, neither of which are directly involved in preparing the body for a rapid response to danger or stress.

4. Imaginary unit multiples are used to represent numbers that cannot be obtained on the number line. Which of the following is equivalent to 5i?

• A. -5
• B. i^5
• C. 5√-1
• D. 1/5i

Correct answer: C

Rationale: Rationale: - The imaginary unit, denoted as "i," is defined as the square root of -1. - Therefore, 5i can be expressed as 5 times the square root of -1, which is equivalent to 5√-1. - Option A, -5, is a real number and not an imaginary unit multiple. - Option B, i^5, is equal to i because i raised to any power that is a multiple of 4 results in 1, and i^5 is equivalent to i. - Option D, 1/5i, is the reciprocal of 5i and not equivalent to 5i.

5. A doctor orders 1 gram of a medication to be administered intravenously. The available vial contains 200 milligrams per milliliter. How many milliliters of the solution should be drawn up?

• A. 4 milliliters
• B. 5 milliliters
• C. 10 milliliters
• D. 20 milliliters

Correct answer: B

Rationale: First convert grams to milligrams (1 gram * 1000 milligrams/gram = 1000 milligrams). Then, divide the desired dosage by the concentration per milliliter: 1000 milligrams / 200 milligrams/milliliter = 5 milliliters.

6. Two objects with equal masses collide head-on, both initially moving at the same speed. After the collision, they stick together. What is their final velocity?

• A. Zero
• B. Half their initial velocity
• C. Their initial velocity
• D. Twice their initial velocity

Correct answer: A

Rationale: In an inelastic collision like this, kinetic energy is not conserved, but momentum is. Since the total momentum before the collision was zero (equal and opposite velocities), it must be zero after the collision as well, resulting in both objects stopping.

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