Chap 25 study guide urinary system

• Functions of the urinary system

  • Regulating total water volume and solute concentration in water
  • Regulating ion concentrations in extracellular fluid
  • Ensuring long term axis base balance
  • Excreting metabolic wastes, toxins, drugs
  • Produces enthropoeitin
  • Activating Vitamin D
  • Carrying out gluconeogenesis
• The right kidney sits lower than the left because of the position of the liver
• Structures/organs that make up the urinary system besides the kidneys

  • Urethra
  • Ureters
  • Urinary bladder
• Three layers of supportive tissue surrounding the kidneys

  • Renal Fascia
  • Perirenal fat capsule
  • Fibrous capsule
• Hematuria


  Blood in urine
• Causes of hematuria include trauma to the kidneys, blood clots, lacerations
• Pyelitis


  Infection of the renal pelvis and calyces
• Pyelonephritis


  Infection or inflammation of the entire kidney
• The most common cause of pyelitis and pyelonephritis is fecal bacteria entering the urinary tract
• Renal arteries


  The major artery that feeds blood into the kidneys
• Nephrons


  The structural and functional units in the kidneys
• Two main parts of the nephrons

  • Renal Corpuscle
  • Renal tubule
• The bulk of the nephrons are cortical nephrons
• The nephrons associated with producing concentrated urine are the juxtamedullary neohrons
• Glomerulus


  A type of filtration capillary
• Hydrostatic pressure


  The force that drives water and solutes out of the blood and across the filtration membrane
• Pertubular capilarries


  The cells that lie on the outer surface of the glomerulus
• Three parts of the renal tubule

  • Proximal convoluted tube
  • Nephron loop
  • Distal convoluted tube
• Proximal convoluted tubules


  Function: Reabsorption and secretion
• Nephron loop


  Function: Reabsorption and secretion
• Distal convoluted tubule


  Function: Reabsorption and secretion
• Two types of cells making up the collecting duct

  • Principle cells
  • Intercalated cells
• Principal cells


  Function: Maintain water and Na+
• Intercalated cells


  Function: Maintain acid base in blood
• Flow of urine from the collecting ducts

  1. Renal cortex

  2. Major calyx

  3. Minor calyx

  4. Renal pelvis

  5. Ureter
• Glomerular capillary bed


  • Specialized for filtration, fed and drained by an arteriole
• Peritubular capillaries


  Associated with efferent arterioles
• Vasa recta


  Associated with juxtamedulary nephrons
• Juxtaglomerular complex


  Responsible for regulating filtrate formation and blood pressure
• Chemoreceptors


  Cells that monitor the NaCl concentration in the filtrate
• Glomerulus


  Cells that monitor the blood pressure in the afferent arterioles
• Gap junctions


  Cells that provide communication between the macula densa cells and the granular cells
• A healthy adult produces approximately 1.5 L of urine per day
• To properly maintain the body's blood pressure, water/solute concentration, extracellular fluid concentration and remove waste, the GFR should be about 120-125 ml/min
• Renal autoregulation


  Intrinsic controls that maintain it
• Maintain systemic blood pressure

  Extrinsic controls that maintain it
• Increased blood pressure


  Causes the afferent arterioles to constrict via the myogenic mechanism
• Macula dense cells


  The cells that direct the tubuloglomerular feedback mechanism
• Blood pressure drops too low

  Stimulates the granular cells to secrete the sympathetic nervous system to release norepinephrine
• Blood pressure drops too low


  The sympathetic nerves secrete norepinephrine, the adrenal medulla secretes epinephrine