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 Step 2: Tubular Reabsorption

Anatomy & Physiology

25. The Urinary System

Renal Physiology Step 2: Tubular Reabsorption

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Multiple Choice

Where does most nutrient reabsorption occur in the nephron?

Collecting duct

Loop of Henle

Proximal convoluted tubule

Distal convoluted tubule

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Verified step by step guidance

Begin by understanding the structure of the nephron, which is the functional unit of the kidney. The nephron consists of several parts: the glomerulus, proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting duct.

Recognize that the proximal convoluted tubule (PCT) is the first segment of the nephron tubule after the glomerulus. It plays a crucial role in reabsorbing nutrients, ions, and water from the filtrate back into the bloodstream.

Identify the types of substances reabsorbed in the proximal convoluted tubule. These include glucose, amino acids, sodium ions, chloride ions, and water. The PCT is responsible for reabsorbing approximately 65-70% of the sodium and water, and nearly all glucose and amino acids.

Understand the mechanisms of reabsorption in the proximal convoluted tubule. This involves active transport, facilitated diffusion, and osmosis. Sodium ions are actively transported out of the tubule cells, creating an osmotic gradient that drives water reabsorption.

Compare the proximal convoluted tubule with other parts of the nephron. While the loop of Henle, distal convoluted tubule, and collecting duct also participate in reabsorption, the PCT is the primary site for nutrient reabsorption due to its extensive surface area and the presence of microvilli that increase absorption efficiency.