Tuesday, May 21, 2013

Kidney #1

The kidney is an essential organ in the excretory system. It performs the following tasks:
  • maintaining blood pressure
  • blood filtration
  • hormone secretion
  • waste excretion
  • pH maintenance

Structure Overview
  • Two kidneys in humans
  • bean-shaped
  • 10-cm long
  • made of tubules and ducts that carry urine
  • contain a dense network of capillaries
  • cortex, medulla, pelvis:
 photo kidney.png

  • solution of metabolic waste
  • contains water, salt, sugars, urine/urea, and other toxins

  • Basic unit of the kidney
  • about a million of nephrons make up one kidney
  • consists of tubules and ducts surrounded by blood vessels:
    • afferent arteriole: carries blood to glomerulus
    • capillaries: surround glomerulus
    • efferent arteriole: capillaries converge and exit the the glomerulus
    • peritubular capillaries: surrounds proximal and distal tubes
    • vasa recta: surrounds loop of henle; countercurrent