Nursing Elites

1. Which muscle has involuntary cells that are branched and striated and connected by intercalated discs with gap junctions?

• A. Smooth muscle
• B. Cardiac muscle
• C. Skeletal muscle
• D. Epithelial muscle

Correct answer: B

Rationale: The correct answer is B: Cardiac muscle. Cardiac muscle cells fit the description provided in the question; they are involuntary, striated, and branched, with intercalated discs containing gap junctions that allow for synchronized contractions of the heart. Smooth muscle (choice A) lacks striations and is found in the walls of internal organs. Skeletal muscle (choice C) is voluntary and attaches to bones for movement. 'Epithelial muscle' (choice D) is not a valid muscle type, making it an incorrect choice.

2. Where is the scaphoid bone located in the body?

• A. Wrist
• B. Shoulder
• C. Spine
• D. Face

Correct answer: A

Rationale: The correct answer is A: Wrist. The scaphoid bone is one of the carpal bones located in the wrist. It is a small boat-shaped bone that is frequently involved in wrist injuries, such as falls onto an outstretched hand resulting in a scaphoid fracture. Choices B, C, and D are incorrect as the scaphoid bone is not located in the shoulder, spine, or face. Understanding the anatomical location of bones is crucial for diagnosing and treating injuries accurately.

3. When animals eat, insulin is released from the pancreas, stimulating glucose uptake by the liver. When glucose levels drop, the pancreas reduces insulin release. This is an example of which mechanism for maintaining homeostasis?

• A. Negative feedback.
• B. Positive feedback.
• C. Stress response.
• D. Parasympathetic regulation.

Correct answer: A

Rationale: This mechanism is an example of negative feedback. Negative feedback systems work to counteract changes in the body and maintain a stable internal environment (homeostasis). In this case, the release of insulin in response to high glucose levels is followed by a reduction in insulin release when glucose levels drop. This response helps regulate glucose levels and return them to a normal range, demonstrating the characteristic of negative feedback where the body's response opposes the initial stimulus to maintain equilibrium. Positive feedback would amplify the initial change rather than counteract it, so it is not the correct choice. Stress response and parasympathetic regulation are not directly involved in this glucose regulation process, making them incorrect choices.

4. Which type of wave requires a medium to travel through?

• A. Electromagnetic waves
• B. Mechanical waves
• C. Sound waves
• D. Both A and C

Correct answer: B

Rationale: Mechanical waves, unlike electromagnetic waves, require a medium (such as air, water, or solids) to propagate. Sound waves are a specific type of mechanical wave that necessitates a medium, like air or water, for transmission. Electromagnetic waves, on the other hand, can travel through a vacuum as they do not rely on a medium for propagation. Choice A (Electromagnetic waves) is incorrect since they do not require a medium to travel. Choice C (Sound waves) is partially correct in that it is a type of mechanical wave that needs a medium but is not the only type. Choice D (Both A and C) is incorrect because electromagnetic waves do not require a medium, only mechanical waves like sound waves do.

5. Which of the following can weaken the immune system and increase susceptibility to infections?

• A. Regular exercise
• B. Balanced diet
• C. Chronic stress
• D. Adequate sleep

Correct answer: C

Rationale: Chronic stress can weaken the immune system by increasing the production of stress hormones like cortisol, which can suppress the immune response. This suppression can make individuals more susceptible to infections and illnesses. Conversely, regular exercise, a balanced diet, and adequate sleep actually support a healthy immune system and help strengthen it. Choices A, B, and D are incorrect as they are factors that generally contribute positively to the immune system. Regular exercise, a balanced diet, and adequate sleep are crucial for maintaining overall health and boosting the immune system rather than weakening it.

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