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. Reproduction is the change in body characteristics over time.

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

Correct answer: B

Rationale: Reproduction is the process by which living organisms produce offspring of the same kind. It is not related to changes in body characteristics over time. Therefore, the statement is false. Choices C and D are also incorrect as they do not align with the definition of reproduction.

3. When does cell death first occur?

A. At age 60.
B. At age 50.
C. At puberty.
D. In the fetus.

Correct answer: D

Rationale: Cell death, also known as apoptosis, first occurs during fetal development when specific cells are programmed to die. This process is essential for shaping and organizing tissues and organs. Choices A, B, and C are incorrect because cell death begins much earlier, during fetal development, rather than later in life or at puberty. Understanding the timing of cell death in different stages of life is crucial in developmental biology.

4. What effect does aldosterone secretion have on electrolyte levels?

A. Calcium levels are decreased
B. Sodium levels are increased
C. Potassium levels are increased
D. Magnesium levels are decreased

Correct answer: B

Rationale: Aldosterone is a hormone that primarily acts on the kidneys to increase the reabsorption of sodium and water into the bloodstream. As a result, sodium levels are increased. Choices A, C, and D are incorrect. Aldosterone does not significantly affect calcium, potassium, or magnesium levels.

5. In a normally functioning cardiovascular system, where does the heartbeat originate?

A. Atrioventricular nodes
B. Bundle of His
C. Purkinje fibers
D. Sinoatrial node

Correct answer: D

Rationale: The correct answer is the Sinoatrial (SA) node. The SA node is known as the natural pacemaker of the heart as it initiates the electrical impulses responsible for the heartbeat. The other choices, such as the Atrioventricular (AV) nodes, Bundle of His, and Purkinje fibers, are involved in conducting the electrical signals generated by the SA node to coordinate the heart's contractions. Therefore, they do not serve as the primary origin of the heartbeat.