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Annotate a diagram of the nephron to show the structure and function of each part involved in filtration and reabsorption.
Annotate a diagram of the nephron to show the structure and function of each part involved in filtration and reabsorption.
Answered step-by-step
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:
- 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.
- Components:
- 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.
- 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.
- Components:
- 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.
- 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
Structure | Function |
---|---|
Renal Corpuscle | Filters blood, allowing water and small solutes to enter Bowman’s capsule as filtrate. |
Proximal Convoluted Tubule | Reabsorbs most water, all glucose, amino acids, and many ions back into the bloodstream. |
Loop of Henle | Creates an osmotic gradient; reabsorbs water (descending limb) and sodium/chloride (ascending limb). |
Distal Convoluted Tubule | Further adjusts ion concentrations; reabsorbs sodium/calcium and secretes potassium/hydrogen. |
Collecting Duct | Final site for water reabsorption; regulates urine concentration based on ADH levels. |
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