Annotate a diagram of the nephron to show the structure and function of each part involved in filtration and reabsorption.

Sourav PanNovember 9, 2024

Answered

To annotate a diagram of the nephron, we will highlight the structure and function of each part involved in filtration and reabsorption. Below is a detailed description of the nephron’s components along with their roles in the kidney’s function.

Diagram of the Nephron

While I cannot create visual images directly, I can describe how to draw it and what to include in your diagram. Here’s how to structure it:

Key Structures to Include:

1. Renal Corpuscle:
   • Components:
     • Bowman’s Capsule: A cup-like structure that surrounds the glomerulus.
     • Glomerulus: A tuft of capillaries where blood filtration occurs.
   • Function:
     • Filtration: Blood enters through the afferent arteriole, and due to high pressure, water and small solutes are filtered into Bowman’s capsule, forming filtrate.
2. Proximal Convoluted Tubule (PCT):
   • Description: The first segment of the renal tubule following Bowman’s capsule.
   • Function:
     • Reabsorption: Approximately 65% of filtered water, all glucose, amino acids, and many ions (such as sodium and bicarbonate) are reabsorbed back into the bloodstream via active and passive transport mechanisms.
3. Loop of Henle:
   • Components:
     • Descending Limb: Permeable to water but not to solutes.
     • Ascending Limb: Impermeable to water; actively transports sodium and chloride ions out into the interstitial fluid.
   • Function:
     • Countercurrent Multiplier: Establishes a concentration gradient in the medulla, allowing for further water reabsorption in the collecting duct.
4. Distal Convoluted Tubule (DCT):
   • Description: The segment following the loop of Henle.
   • Function:
     • Selective Reabsorption and Secretion: Reabsorbs sodium and calcium ions under hormonal control (e.g., aldosterone), while secreting potassium and hydrogen ions into the filtrate.
5. Collecting Duct:
   • Description: The final segment where multiple nephrons converge.
   • Function:
     • Final Concentration of Urine: Water reabsorption is regulated by antidiuretic hormone (ADH). It plays a key role in determining urine concentration based on hydration status.

Summary of Functions