Table of contents

1. Introduction to Anatomy & Physiology5h 43m
2. Cell Chemistry & Cell Components12h 36m
3. Energy & Cell Processes10h 6m
4. Tissues & Histology10h 3m
5. Integumentary System2h 20m
6. Bones & Skeletal Tissue2h 16m
7. The Skeletal System2h 35m
8. Joints2h 17m
9. Muscle Tissue2h 33m
10. Muscles1h 11m
11. Nervous Tissue and Nervous System1h 35m
12. The Central Nervous System1h 6m
- Introduction to the Central Nervous System
  18m
- The Cerebrum
  48m
13. The Peripheral Nervous System1h 26m
14. The Autonomic Nervous System1h 38m
15. The Special Senses2h 41m
16. The Endocrine System2h 48m
17. The Blood3h 22m
18. The Heart3h 42m
19. The Blood Vessels3h 35m
20. The Lymphatic System3h 16m
21. The Immune System14h 37m
22. The Respiratory System3h 20m
23. The Digestive System2h 5m
24. Metabolism and Nutrition4h 0m
25. The Urinary System2h 39m
26. Fluid and Electrolyte Balance, Acid Base Balance37m
27. The Reproductive System2h 5m
28. Human Development1h 21m
29. Heredity3h 32m

25. The Urinary System

Renal Physiology: Overview

Anatomy & Physiology

25. The Urinary System

Renal Physiology: Overview

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Multiple Choice

As filtrate moves down the descending limb of the nephron loop, which of the following occurs?

The filtrate becomes more dilute.

Water is reabsorbed into the medullary interstitium.

Glucose is secreted into the filtrate.

Sodium ions are actively transported out of the filtrate.

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Verified step by step guidance

Understand the anatomy of the nephron loop (loop of Henle). The descending limb is permeable to water but not to solutes like sodium or glucose. This is a key feature of its function.

Recognize the osmotic gradient in the medullary interstitium. The interstitial fluid in the medulla has a high concentration of solutes, creating a gradient that drives water reabsorption from the filtrate.

As filtrate moves down the descending limb, water is reabsorbed into the medullary interstitium due to osmosis. This process increases the concentration of solutes in the filtrate, making it more concentrated.

Note that glucose is not secreted into the filtrate in the descending limb. Glucose reabsorption primarily occurs in the proximal tubule, not the nephron loop.

Understand that sodium ions are not actively transported out of the filtrate in the descending limb. Active transport of sodium occurs in the ascending limb, which is impermeable to water.