Nephrons

Definition

Nephrons are the functional units of the kidneys, responsible for the filtration and reabsorption of blood to produce urine. They play a crucial role in maintaining the body's fluid balance, electrolyte levels, and overall renal wellness.

5 Must Know Facts For Your Next Test

1. Each kidney contains approximately 1 million nephrons, which are responsible for the kidney's filtration and reabsorption functions.
2. The glomerulus in the nephron acts as a selective filter, allowing the passage of water, small molecules, and waste products while retaining larger molecules like proteins.
3. The renal tubule reabsorbs essential substances, such as glucose, amino acids, and electrolytes, back into the bloodstream while excreting waste products.
4. The renal cortex is the outer layer of the kidney where the majority of nephrons are located, making it crucial for overall kidney function.
5. Damage or dysfunction of nephrons can lead to various kidney diseases, such as chronic kidney disease and end-stage renal disease.

Review Questions

• Explain the role of nephrons in maintaining fluid balance and electrolyte levels in the body.
  • Nephrons are responsible for regulating fluid balance and electrolyte levels in the body. They do this by filtering the blood, reabsorbing essential substances like water, sodium, and potassium back into the bloodstream, and excreting waste products and excess fluids as urine. This precise control of fluid and electrolyte balance is crucial for maintaining homeostasis and supporting various physiological processes.
• Describe how the structure of the nephron, specifically the glomerulus and renal tubule, contributes to its filtration and reabsorption functions.
  • The glomerulus in the nephron acts as a selective filter, allowing the passage of water, small molecules, and waste products while retaining larger molecules like proteins. This filtered fluid then enters the renal tubule, where it undergoes a series of reabsorption and secretion processes. The renal tubule reabsorbs essential substances, such as glucose, amino acids, and electrolytes, back into the bloodstream while excreting waste products. The unique structure and function of the glomerulus and renal tubule work together to maintain the body's fluid and electrolyte balance.
• Analyze the importance of the renal cortex in overall kidney function and discuss the potential consequences of damage or dysfunction to this region.
  • The renal cortex is the outer layer of the kidney where the majority of nephrons are located, making it crucial for overall kidney function. The high concentration of nephrons in the renal cortex allows for efficient filtration and reabsorption of blood, which is essential for maintaining fluid balance, electrolyte levels, and waste removal. Damage or dysfunction to the renal cortex, such as in chronic kidney disease or end-stage renal disease, can significantly impair the kidney's ability to perform these vital functions, leading to a range of health complications, including fluid and electrolyte imbalances, hypertension, and the accumulation of waste products in the body.

Related terms

Glomerulus: The network of capillaries in the nephron where the initial filtration of blood takes place.

Renal Tubule: The part of the nephron that reabsorbs and secretes substances to produce the final urine.

Renal Cortex: The outer layer of the kidney where the majority of nephrons are located.