Nephron

Definition

A nephron is the basic structural and functional unit of the kidney, responsible for filtering blood and producing urine. Each kidney contains about a million nephrons, which work together to regulate water, electrolyte balance, and waste removal, maintaining overall homeostasis in the body.

5 Must Know Facts For Your Next Test

1. Nephrons consist of two main parts: the renal corpuscle (which includes the glomerulus) and the renal tubule.
2. Each nephron can filter approximately 120 milliliters of blood per minute, contributing to the regulation of blood pressure and fluid balance.
3. The nephron's ability to selectively reabsorb essential substances ensures that only waste products are excreted in urine.
4. Nephrons play a crucial role in acid-base balance by regulating hydrogen ion and bicarbonate levels in the body.
5. Damage to nephrons can lead to chronic kidney disease, highlighting their importance in overall kidney function.

Review Questions

• How does the structure of a nephron support its function in filtering blood?
  • The structure of a nephron is uniquely designed to optimize blood filtration. The glomerulus, a tuft of capillaries within the renal corpuscle, allows for high-pressure filtration of blood, facilitating the movement of water and small solutes into the Bowman’s capsule. Following this, the renal tubule adjusts the filtrate through selective reabsorption and secretion processes, ensuring that essential substances are retained while waste products are excreted.
• Discuss how nephrons contribute to maintaining homeostasis in the body.
  • Nephrons maintain homeostasis by regulating fluid volume, electrolyte concentrations, and waste removal. They achieve this through processes like filtration at the glomerulus, reabsorption in the renal tubule, and secretion of excess substances. By adjusting urine concentration and volume according to the body's hydration status or dietary intake, nephrons help control blood pressure and maintain acid-base balance.
• Evaluate the impact of nephron damage on renal function and overall health.
  • Damage to nephrons significantly impairs renal function, leading to conditions such as chronic kidney disease or acute kidney injury. As nephron numbers decrease or their functionality declines, the kidneys struggle to filter blood effectively, resulting in fluid overload, electrolyte imbalances, and accumulation of waste products. This deterioration can cause serious health issues, necessitating interventions like dialysis or kidney transplantation to manage the consequences of compromised renal function.

Related terms

glomerulus: A network of capillaries located at the beginning of each nephron where blood filtration occurs.

renal tubule: The part of the nephron that reabsorbs water and nutrients from the filtrate and secretes waste products into the urine.

urine: The liquid waste product produced by the kidneys, composed of water, salts, urea, and other metabolites.