which part of the nephron is closest to the collecting duct

ATI RN

ATI Anatomy and Physiology

1. Which part of the nephron is closest to the collecting duct?

A. Distal convoluted tubule (DCT)
B. Bowman's Capsule
C. Afferent Arteriole
D. Proximal Convoluted Tubule (PCT)

Correct answer: A

Rationale: The correct answer is the Distal convoluted tubule (DCT). The DCT is the part of the nephron closest to the collecting duct, where the final adjustments to electrolyte and fluid balance are made. Bowman's Capsule is located at the beginning of the nephron, where filtration of blood occurs. The Afferent Arteriole brings blood to the glomerulus for filtration. The Proximal Convoluted Tubule (PCT) is situated after the Bowman's Capsule and is not the part closest to the collecting duct.

2. Which of the following hormones is secreted by the posterior pituitary gland?

A. Growth hormone
B. Luteinizing hormone
C. Adrenocorticotropic hormone
D. Antidiuretic hormone

Correct answer: D

Rationale: The correct answer is D: Antidiuretic hormone. Antidiuretic hormone (ADH), also known as vasopressin, is produced by the hypothalamus and stored in the posterior pituitary gland. It plays a key role in regulating the body's water balance by controlling the amount of water reabsorbed by the kidneys. Choices A, B, and C are incorrect because Growth hormone is produced by the anterior pituitary gland, Luteinizing hormone is produced by the anterior pituitary gland, and Adrenocorticotropic hormone is produced by the anterior pituitary gland.

3. One characteristic that centenarians share is

A. a high level of exercise throughout life
B. long-lived relatives
C. following the Mediterranean diet
D. never having smoked

Correct answer: D

Rationale: The correct answer is 'never having smoked.' Research suggests that one of the common characteristics among centenarians is that they have never smoked. Smoking is a well-known risk factor for various diseases and can significantly reduce lifespan. Choice A, 'a high level of exercise throughout life,' is not a universal characteristic among centenarians, although exercise can contribute to a healthy lifestyle. Choice B, 'long-lived relatives,' while genetics can play a role in longevity, not all centenarians have long-lived relatives. Choice C, 'following the Mediterranean diet,' is a healthy dietary choice but not a defining characteristic shared by all centenarians.

4. The maintenance of a steady body temperature in the face of fluctuating environmental conditions illustrates homeostasis.

A. TRUE
B. FALSE
C. Not Sure
D. None of the above

Correct answer: A

Rationale: The correct answer is True. Homeostasis is the body's ability to maintain a stable internal environment despite external changes. In this case, the maintenance of a steady body temperature despite fluctuations in environmental conditions is a clear example of homeostasis. The body regulates temperature through processes like sweating when it's hot and shivering when it's cold. Choices B, C, and D are incorrect because the statement provided does indeed illustrate the concept of homeostasis, making them inaccurate.

5. Which of the following is the measurement of the percentage of red blood cells in whole blood?

A. Hematocrit
B. Hemoglobin
C. Mean corpuscular volume
D. Reticulocyte count

Correct answer: A

Rationale: The correct answer is 'Hematocrit.' Hematocrit is the measurement of the percentage of red blood cells in whole blood. It is used to diagnose conditions such as anemia and dehydration. Choice B, 'Hemoglobin,' measures the amount of hemoglobin in the blood, not the percentage of red blood cells. Choice C, 'Mean corpuscular volume,' measures the average volume of a red blood cell, not the percentage of red blood cells. Choice D, 'Reticulocyte count,' measures the percentage of young red blood cells in the blood, not the percentage of red blood cells.