Nursing Elites

1. What property of a substance refers to its ability to be drawn into thin wires?

• A. Conductivity
• B. Ductility
• C. Viscosity
• D. Malleability

Correct answer: b

Rationale: Ductility refers to a substance's ability to be drawn into thin wires without breaking.

2. Which hormone, produced by the pituitary gland, stimulates the production of milk in mammary glands during breastfeeding?

• A. Growth hormone (GH)
• B. Thyroid-stimulating hormone (TSH)
• C. Prolactin
• D. Follicle-stimulating hormone (FSH)

Correct answer: c

Rationale: The correct answer is C: Prolactin. Prolactin is the hormone produced by the pituitary gland that stimulates the production of milk in the mammary glands during breastfeeding. It plays a crucial role in lactation by promoting the growth and development of the mammary glands and initiating the production of milk. Growth hormone (GH) regulates growth and metabolism, not milk production. Thyroid-stimulating hormone (TSH) stimulates the thyroid gland, not mammary glands. Follicle-stimulating hormone (FSH) is involved in reproductive processes, not milk production. Therefore, prolactin is the hormone directly responsible for stimulating milk production during breastfeeding.

3. During embryonic development, all tissues originate from

• A. Epithelial tissue only
• B. Muscle tissue only
• C. Connective tissue only
• D. Embryonic germ layers

Correct answer: D

Rationale: During embryonic development, all tissues originate from the three primary embryonic germ layers: ectoderm, mesoderm, and endoderm. These layers give rise to all the different types of tissues found in the body. The ectoderm forms the skin and nervous system, the mesoderm gives rise to muscle, bone, and connective tissues, while the endoderm develops into the lining of the digestive and respiratory systems. Therefore, option D is the correct answer as it encompasses the comprehensive origin of all tissues in the body during embryonic development.

4. What happens to the frequency of a wave when its wavelength is doubled, assuming the speed remains constant?

• A. Frequency remains the same.
• B. Frequency is halved.
• C. Frequency is doubled.
• D. Frequency information is insufficient to determine.

Correct answer: C

Rationale: Since the wave speed is constant, if the wavelength increases, the frequency must decrease to maintain the same energy transfer per unit time.

5. 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.

6. During a healthy heartbeat, the P wave on an ECG represents

• A. The repolarization of the ventricles.
• B. The electrical conduction through the AV node.
• C. The contraction phase of the ventricles (systole)
• D. The depolarization of the atria.

Correct answer: D

Rationale: The correct answer is D: The P wave on an ECG represents the depolarization of the atria. During a healthy heartbeat, the P wave is the first positive deflection seen on the ECG and reflects the initiation of the electrical impulse in the atria, leading to atrial contraction. It is followed by the QRS complex, which represents the depolarization of the ventricles. Options A, B, and C are incorrect because the P wave specifically corresponds to atrial depolarization, not repolarization of the ventricles, electrical conduction through the AV node, or ventricular contraction. Understanding the sequence of electrical events in the heart as represented on an ECG is crucial for interpreting cardiac function and identifying potential abnormalities.

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