Nursing Elites

1. Which term refers to the point of contact between a motor neuron and a muscle fiber, where communication occurs to initiate muscle contraction?

• A. Sarcomere
• B. Synapse
• C. Tendon
• D. Myofibril

Correct answer: b

Rationale: The correct answer is B: Synapse. A synapse is the point of contact between a motor neuron and a muscle fiber. At the synapse, communication occurs in the form of neurotransmitters being released from the neuron and binding to receptors on the muscle fiber, initiating muscle contraction. A sarcomere refers to the basic contractile unit of a muscle fiber, not the point of contact between a motor neuron and muscle fiber. A tendon is a fibrous connective tissue that connects muscle to bone, not the communication point. Myofibril is a structure within muscle fibers that contains sarcomeres, but it is not the specific term for the point of contact between a motor neuron and muscle fiber.

2. Deficiency in which vitamin can lead to a condition called pernicious anemia, affecting vitamin B12 absorption in the digestive system?

• A. Vitamin A
• B. Vitamin B12 (cobalamin)
• C. Vitamin D
• D. Vitamin E

Correct answer: B

Rationale: The correct answer is B: Vitamin B12 (cobalamin). Pernicious anemia is a condition caused by a deficiency in vitamin B12, which is essential for the production of red blood cells and for the proper functioning of the nervous system. This vitamin is primarily absorbed in the digestive system, particularly in the ileum of the small intestine. In pernicious anemia, there is a lack of intrinsic factor, a protein produced by the stomach, which is necessary for the absorption of vitamin B12. Deficiencies in other vitamins like Vitamin A, Vitamin D, or Vitamin E do not directly lead to pernicious anemia. Therefore, the correct answer is Vitamin B12.

3. Identify the appositive in the following sentence: "My favorite author, Agatha Christie, wrote many detective novels."

• A. favorite
• B. Agatha Christie
• C. many
• D. novels

Correct answer: B

Rationale: An appositive renames or clarifies the noun or pronoun preceding it.

4. Microfilaments and microtubules are both components of the cytoskeleton, but they have different functions. Which of these describes microfilaments?

• A. Provide structural support and shape
• B. Facilitate cell movement and contraction
• C. Form the mitotic spindle during cell division
• D. Transport materials within the cell

Correct answer: B

Rationale: Microfilaments are composed of actin filaments and are responsible for facilitating cell movement and contraction. They play a crucial role in processes such as muscle contraction, cell division, and cell shape changes. Microfilaments are involved in generating forces for cell motility and maintaining cell shape, making option B, 'Facilitate cell movement and contraction,' the correct choice. The other options are not accurate for microfilaments: A) Structural support and shape are primarily provided by intermediate filaments, C) Mitotic spindle formation is attributed to microtubules, and D) Transport of materials within the cell is usually carried out by microtubules and motor proteins.

5. What happens during a physical change in matter?

• A. A new substance with different properties is formed
• B. The chemical composition of the substance changes
• C. The original substance can be recovered by physical means
• D. Energy is either released or absorbed

Correct answer: C

Rationale: During a physical change in matter, the original substance undergoes a change in its physical state or appearance without any change in its chemical composition. This means that the original substance can be recovered by physical means, such as melting, freezing, boiling, or condensing. No new substance is formed (option A), the chemical composition remains the same (option B), and energy changes can occur but are not a defining characteristic of a physical change (option D).

6. Which part of the heart generates the QRS complex on an ECG?

• A. Sinoatrial node (SA node)
• B. Atrioventricular node (AV node)
• C. Bundle of His
• D. Ventricular muscle cells

Correct answer: D

Rationale: The correct answer is D, ventricular muscle cells. The QRS complex on an ECG represents the depolarization of the ventricles. This electrical activity is generated by the spread of impulses through the bundle branches and Purkinje fibers to the ventricular muscle cells. The SA node (option A) is responsible for initiating the electrical impulse in the heart, but it does not directly generate the QRS complex. The AV node (option B) delays the impulse to allow for proper coordination of atrial and ventricular contractions. The Bundle of His (option C) and its branches facilitate the conduction of the electrical signal from the AV node to the ventricles but do not generate the QRS complex directly.

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