4. Renal physiology 1 - Collins

• Glomerulus or bowman's capsule - function - filtration
• Proximal convoluted tubule - function - reabsorption and secretion
• Loop of Henle function - reabsorption and secretion
• distal convoluted tubule function - reabsorption and secretion
• collecting ducts function - reabsorption, secretion and excretion
• nephron consist of?

  glomerulus and renal tubules
• What 2 part of nephron function in 1st step in formation of urine?

  glomerulus and bowman's capsule
• reabsorption is transport from tubules lumen into the bloodstream
• secretion is transport from the bloodstream into the tubule lumen
• 2 types of nephron - cortical and juxtamedullary

  • juxtamedullary - have long loops of henle and well developed vasa recta
• vasa recta and loops of henle is arranged in?

  parallel
• Glomerular capillaries and the peritubular capillaries have low resistance - why?

  parallel arrangement which is why there is pressure drop in afferent and efferent arterioles
• Largest pressure drop is in the afferent and efferent arterioles
• The major mechanism for changing blood flow is by changing arteriolar resistance.
• Renal blood flow( (RBF) can be changed by changing?

  • afferent arteriolar resistance
  • efferent arteriolar resistance
• Increasing resistance of afferent or efferent arterioles will - do what to renal blood flow?

  decrease renal blood flow
• renal autoregulation: resistance is controlled at afferent arteriole
• renal autoregulation are controlled by

  • myogenic mechanism
  • tubuloglomerular feedback
• Myogenic response is Gq dependent

  • activate PLC
  • increase DAG and IP3
• Myogenic response

  1. increase arterial pressure
  2. stretch of afferent arteriole
  3. activation of vascular smooth muscle
  4. vasoconstriction of afferent arteriole
  5. decrease RBF