Nursing Elites

1. Which of the following describes a vector quantity?

• A. Speed
• B. Distance
• C. Mass
• D. Velocity

Correct answer: d

Rationale: Velocity is a vector quantity as it includes both magnitude (speed) and direction.

2. The microscopic functional unit of the kidney responsible for filtering blood is the:

• A. Ureter
• B. Nephron
• C. Renal pelvis
• D. Bladder

Correct answer: B

Rationale: The correct answer is B: Nephron. The nephron is the microscopic functional unit of the kidney responsible for filtering blood and producing urine. It consists of the glomerulus, Bowman's capsule, proximal convoluted tubule, loop of Henle, and distal convoluted tubule. The other options, A: Ureter, C: Renal pelvis, and D: Bladder, are incorrect as they are not parts of the nephron but rather other structures involved in the urinary system. The ureter is a tube that carries urine from the kidneys to the bladder, the renal pelvis is a funnel-shaped structure in the kidney that collects urine, and the bladder stores urine before it is excreted from the body.

3. A keystone species plays a critical role in an ecosystem because its removal would:

• A. Lead to a decrease in competition among other species
• B. Cause a slight increase in primary productivity
• C. Have a minimal impact on the overall ecosystem structure
• D. Disrupt the food web and cause cascading effects on other populations

Correct answer: D

Rationale: Rationale: Keystone species are species that have a disproportionately large effect on their environment relative to their abundance. They play a critical role in maintaining the structure and function of an ecosystem. If a keystone species is removed from an ecosystem, it can disrupt the food web by causing imbalances in predator-prey relationships. This disruption can lead to cascading effects on other populations within the ecosystem, potentially causing population declines or even extinctions. Therefore, the removal of a keystone species would have significant impacts on the overall ecosystem structure, making option D the correct answer.

4. Antidiuretic hormone (ADH) helps the kidneys regulate:

• A. Acid-base balance
• B. Blood pressure
• C. Urine output by controlling water reabsorption
• D. All of the above

Correct answer: C

Rationale: The correct answer is C: 'Urine output by controlling water reabsorption.' Antidiuretic hormone (ADH) is released by the pituitary gland and acts on the kidneys to regulate water reabsorption. When ADH levels are high, the kidneys reabsorb more water, leading to concentrated urine and decreased urine output. This helps maintain the body's water balance and prevent dehydration. While ADH indirectly influences blood pressure by regulating blood volume, its primary function is to control water balance, not acid-base balance. Therefore, the correct answer is C.

5. Which muscle plays a significant role in the process of forced exhalation by contracting to reduce the thoracic cavity volume?

• A. Diaphragm
• B. External intercostal muscles
• C. Internal intercostal muscles
• D. Abdominal muscles

Correct answer: C

Rationale: The correct answer is C: Internal intercostal muscles. During forced exhalation, these muscles contract to depress the ribs and decrease the thoracic cavity volume, assisting in pushing air out of the lungs. The diaphragm is primarily responsible for inhalation by contracting to increase thoracic cavity volume. External intercostal muscles aid in inhalation by elevating the ribs. Abdominal muscles are involved in activities like coughing, sneezing, and forced exhalation by compressing the abdominal contents to further reduce thoracic volume. Therefore, the internal intercostal muscles have a significant role in forced exhalation.

6. The critical angle is defined as the minimum angle of incidence in a denser medium for which light undergoes:

• A. Total internal reflection
• B. Continued refraction
• C. Specular reflection
• D. Increased dispersion

Correct answer: A

Rationale: The critical angle is the minimum angle of incidence at which light is totally internally reflected rather than refracted. When light travels from a denser medium to a rarer medium at an angle greater than the critical angle, it undergoes total internal reflection. This phenomenon is crucial in applications like fiber optics and mirages. Continued refraction (option B) occurs when light enters a medium at an angle less than the critical angle. Specular reflection (option C) refers to the reflection of light at a smooth surface. Increased dispersion (option D) involves the separation of light into its constituent colors due to varying refractive indices, which is not directly related to the critical angle. Therefore, the correct answer is A - total internal reflection.

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