- Filtration, reabsorption, and secretion occur in specific segments of the nephron and system

Question

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Proximal convoluted
• tubule (PCT)
Distal convoluted tubule (DCT)
absorbs water and im ions in response to ormones; secretes rogen and potassium
Glomerulus
sorbs water and salt; ates a concentration gradient
rs water and solutes rom plasma while lining cells and large proteins
Glomerular capsule
Collecting duct
ecretion of wastes; sorbs water and ions
Nephron loop

Answer 1

Here's a brief overview of the functions and processes that occur in the specified segments of the nephron:

1. Glomerulus

• Function: The glomerulus is a network of capillaries that is involved in the initial filtration of blood.
• Processes:
  • Filtration: It filters blood plasma, allowing water, ions, and small solutes to pass while retaining large proteins and blood cells.
  • Formation of filtrate: The filtrate enters the glomerular capsule.

2. Glomerular Capsule (Bowman's Capsule)

• Function: This capsule surrounds the glomerulus and collects the filtrate that has been filtered from the blood.
• Processes:
  • Acts as a receptacle for the filtered fluid, which then proceeds into the nephron's tubular system.

3. Proximal Convoluted Tubule (PCT)

• Function: This segment is primarily responsible for reabsorption.
• Processes:
  • Reabsorption: A significant amount of water, ions (such as sodium), and nutrients (like glucose and amino acids) are reabsorbed into the bloodstream.
  • Secretion: Some waste products and excess ions are also secreted into the tubular fluid.

4. Nephron Loop (Loop of Henle)

• Function: This component is essential for creating a concentration gradient in the renal medulla.
• Processes:
  • Descending Limb: Permeable to water but not to solutes, leading to water reabsorption.
  • Ascending Limb: Impermeable to water, actively reabsorbs sodium and chloride, which contributes to the concentration gradient in the medulla.

5. Distal Convoluted Tubule (DCT)

• Function: This segment fine-tunes the reabsorption and secretion of ions, under hormonal control.
• Processes:
  • Reabsorption: Water and ions (like sodium and calcium) are reabsorbed in response to hormones like aldosterone.
  • Secretion: Hydrogen ions and potassium are secreted into the tubular fluid to help maintain acid-base balance.

6. Collecting Duct

• Function: This final segment of the nephron primarily regulates water reabsorption and the final concentration of urine.
• Processes:
  • Reabsorption: Water is reabsorbed based on the body's needs, which is regulated by antidiuretic hormone (ADH).
  • Secretion: Additional secretion of waste products and further regulation of electrolyte balance occurs.

Conclusion

Together, these segments of the nephron play intricate roles in filtering blood, reabsorbing valuable substances, maintaining fluid and electrolyte balance, and excreting wastes, ultimately contributing to homeostasis in the body.