Structure of Nephron

• What is the main function of the nephron?

  To filter blood and create urine
• Where does filtration and osmoregulation occur in the kidney?

  In the nephrons
• How many nephrons are there in each kidney?

  About 1 million
• What are the main parts of the nephron?

  • Renal capsule (Bowman's capsule)
  • Proximal convoluted tubule (PCT)
  • Loop of Henle
  • Distal convoluted tubule (DCT)
  • Collecting duct
• What is the role of the renal capsule?

  To enclose the glomerulus for filtration
• What happens in the proximal convoluted tubule?

  Selective reabsorption of glucose and water
• What is ultrafiltration?

  Process of filtering blood under high pressure
• What is the filtrate called after it passes into the renal capsule?

  Glomerular filtrate
• Why are proteins and blood cells not found in urine?

  They are too large to be filtered out
• How is glucose reabsorbed in the proximal convoluted tubule?

  By active transport with sodium ions
• What is the role of mitochondria in the proximal convoluted tubule?

  To provide energy for active transport
• What is the function of the Loop of Henle?

  To maintain sodium ion concentration gradient
• What happens in the ascending limb of the Loop of Henle?

  Sodium ions are actively transported out
• How does water move out of the descending limb of the Loop of Henle?

  By osmosis into the interstitial space
• What is the effect of a longer Loop of Henle in desert animals?

  More water is reabsorbed into the blood
• What are the steps of urine formation in the nephron?

  1. Ultrafiltration in the renal capsule
  2. Selective reabsorption in the PCT
  3. Sodium ion gradient maintenance in the Loop of Henle
  4. Further reabsorption in the DCT and collecting duct
  5. Formation of urine
• What is the final product of the nephron's filtration process?

  Urine
• What is the importance of reabsorption in the kidneys?

  To retain useful substances and water
• What happens to the filtrate in the distal convoluted tubule?

  Further water is reabsorbed by osmosis
• What is the role of the collecting duct?

  To collect urine before it exits the kidney
• How does the concentration of urine differ in desert animals?

  It is more concentrated to conserve water
• What is the significance of the negative feedback in osmoregulation?

  It regulates water balance in the body
• What should never be found in urine of a healthy person?

  Proteins, blood cells, and glucose
• Why is it important to use the term 'reabsorb' in kidney function?

  It indicates substances are taken back into blood