kidney

• weight: 150g, height: 11 cm
• cortex: outer part where blood is filtered; some selective reabsorption happens
• medulla: inner part where some selective reabsorption happens and fluid is collected from urine
• ureter: carries urine to the bladder
• kidney helps balance water to avoid animal cells from bursting
• nephron: main functional unit of kidney, nephron
• nephrons filter blood seperating waste and returning substance that are needed back in the bloodstream
• each kidney has millions of nephrons
• the glomerus:

  • network of capillaries
  • blood is filtered under high pressure
  • water, glucose, ions, rea leave the capillaries and enter tubules
  • protein molecules are too large to leave the capillaries; so they stay in the blood
• tubules:

  • substances entering tubules are specifically reabsorbed:
  • all of the glucose
  • most water + ions
  • urea is not reabsorbed but instead remains dissolved in the liquid inside tubule -> forms urine
• tubules:

  • substances entering tubules are specifically reabsorbed:
  • all of the glucose
  • most water + ions
  • urea is not reabsorbed but instead remains dissolved in the liquid inside tubule -> forms urine
• Urine:

  • urine is found as a result of filtration in the glomerus and selective reabsorption in the tubule
  • remove waste containing nitrogen (urea)
  • regulate the amount of water lost from the body
  • mantain the blood at constant ph
  • control concentration of salts in the blood
  • remove alcohol, drugs, hormones -> foreign substance
  • return glucose, amino acids and other essential substances to the body/ blood