Urinary System

  1. what organs make up the urinary system?
    • two kidneys
    • two ureters
    • one urinary bladder 
    • one urethra
  2. What is the function of the kidneys?
    • 1-regulation of blood ionic composition
    • 2-regulation of blood pH
    • 3-regulation of blood volume
    • 4-regulation of blood pressure
    • 5-regulation of blood glucose
    • 6-maintenance of blood osmolarity
    • 7-production of hormones
    • 8-excretion of waste & foreign substances
  3. what ions do the kidneys regulate?
    • calcium (Ca++)
    • sodium ions (Na+)
    • potassium (K+)
    • chloride ions (Cl-)
    • phosphate ions (HPO4--)
  4. what are the two ions that regulate blood pH?
    • hydrogen ions (k+)
    • bicarbonate ions (HCO3-)
  5. how do the kidneys regulate blood volume?
    by conserving or eliminating water in the urine
  6. what enzymes are important for regulating blood pressure?
    enzyme renin which regulates the renin-angiotensin-aldosterone pathway
  7. how does the kidney regulate blood osmolarity?
    by separately regulating the loss of water and the loss of solutes
  8. what is the osmolarity of blood?
    about 300 milliosmoles per liter
  9. what two hormones do the kidneys produce?
    calcitriol and erythropoeitin
  10. what waste products does the kidney excrete?
    • ammonia & urea from deamination of amino acids
    • bilirubin from catabolism of hemoglobin

    creatinine from creatine phosphate in muscle
  11. which organs are retroperitoneal?
    kidneys, ureters and bladder
  12. what structures define trigone?
    2 ureters and 1 urethra
  13. what does the term micturition mean?
    emptying urine from bladder
  14. how is urine moved through the ureters?
    • one of three ways
    • 1-gravity
    • 2-peristaltic waves
    • 3-Hydrostatic pressure
  15. which kidney is inferior in location?
    the right kidney
  16. what are the 3 layers that cover the kidney?
    • 1-renal capsule-inner-most
    • 2-adipose capsule-middle layer
    • 3-renal fascia-outer-most layer
  17. what percent of people have cortical nephrons?
  18. what percent of people have a juxtamedullary nephron?
  19. what is the histology of loop of henle?
    simple cuboidal to low columnar cells
  20. what is the histology of macula densa cells?
    columnar tubule cells
  21. what is the histology of juxtaglomerular cells?
    modified  smooth muscle cells
  22. what structures make up the filtration membrane?
    glomerular capillaries and podocytes
  23. what are mesangial cells?
    contracting cells that regulate glomerular filtration
  24. what is the juxtaglomerular apparatus?
    macula densa cells and juxtaglomerular cells that regulate blood flow into the glomerulus
  25. what is the function of principal cells?
    to control the concentration of urine via ADH and aldosterone receptors
  26. what is the function of intercalated cells?
    help homeostasis of blood pH
  27. what are the 3 function of the nephron?
    • 1-filtration
    • 2-secretion
    • 3-reabsorption
  28. what are the 3 filtration membranes in the glomerulus?
    1-fenestrations- prevents filtration of blood cell

    2-basal lamina- prevents filtration of large proteins

    3-slit membrane between pedicels-prevents filtration of medium sized proteins
  29. why is the volume of fluid filtered by the renal corpuscle much larger than other capillaries?
    • 1-larger filtration surface
    • 2-filtration membrane is thin and porous
    • 3-high blood pressure in glomerulus
  30. what are the three pressure responsible for net filtration?
    GBHP, CHP and BCOP
  31. define net filtration
    the total pressure that promotes filtration
  32. what is the typical NFP?
    10 mmHg
  33. what are the three mechanisms that regulate GFR?
    • 1-renal autoregulation
    • 2-neural regulation
    • 3-hormonal regulation
  34. what are the two sub-mechanisms in autoregulation?
    1-myogenic regulation-stimulated by blood pressure

    2-tubuloglomerular feedback system-increase of GLR via increase of Na+, Cland H2O
  35. what is the function of nitric oxide? (NO)
    an increase in nitric oxide dilates arteriole

    a decrease in nitric oxide constricts arteriole
  36. describe neural regulation
    sympathetic nerves release norepinephrine which constricts afferent arteriole via alpha receptors and release of renin
  37. describe hormonal regulation of GFR
    angiotensin II reduces GFR and ANP increases GFR
  38. what are the two reabsorption routes?
    1-paracellular-between cells

    2-transcellular-through the cells
  39. what are the two transport mechanisms for solutes?
    primary active transport and secondary active transport
  40. how does ADH regulate water reabsorption?
    increase water permeability in principal cells
  41. how does ANP regulate reabsorption and secretion?
    increase capillary surface area for filtration
Card Set
Urinary System
chapter 26