A&P renal system

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A&P renal system
2013-07-26 10:12:33

A&P exam 6
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  1. what separates the ICF from the ECF
    plasma membrane
  2. what separates the plasma from the interstitial fluid
    capillary wall
  3. this is a passive process whereby solutes move across a permeable membrane from an area of higher concentration to an area of lower concentration
  4. this is a type of diffusion whereby water moves across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration
  5. movement of substances between the blood and the interstitial fluid is known as what
    capillary exchange
  6. what are the three mechanisms that continually exchange substances between the blood and interstitial fluid
    • diffusion
    • transcytosis
    • bulk flow
  7. the most important mechanism for solute exchange between the blood and interstitial fluid is what
  8. the transport mechanism for large, lipid-insoluble molecules that cannot pass through the capillary walls to the interstitial fluid any other way is what
  9. this is a passive process whereby large numbers of ions, molecules and particles in fluid move together in the same direction is known as what
    bulk flow
  10. in bulk flow, this is a pressure-driven movement from the blood capillaries into the interstitial  fluid
  11. in bulk flow, this is a pressure-driven movement from the interstitial fluid into the blood capillaries
  12. what are the pressures that promote filtration
    • blood hydrostatic pressure
    • interstitial fluid osmotic pressure
  13. for pressures that promote filtration, what is the pressure generated by the pumping action of the heart
    blood hydrostatic pressure
  14. for pressures that promote filtration, what is the pressure exerted by the presence of small proteins in interstitial fluid (this pressure is normally very low: ~1mmHg)
    interstitial fluid osmotic pressure
  15. what are the pressures that promote reabsorption
    • blood colloid osmotic pressure
    • interstitial fluid hydrostatic pressure
  16. in the pressures that promote reabsorption, what is the pressure exerted by colloidal suspension of large plasma proteins
    blood colloid osmotic pressure
  17. in the pressures that promote reabsorption, this pressure is normally very low
    interstitial fluid hydrostatic pressure
  18. the balance of all 4 pressure that determines if the volume of blood and interstitial fluid changes or remains steady is known as what
    net filtration
  19. this explains the near equilibrium between the fluid and solutes in the plasma and the interstitial fluid
    starlings law of the capillaries
  20. which pressures promote filtration across the capillary wall
    BHP and IFOP
  21. which pressures promote reabsorption across the capillary wall
    BCOP and IFHP
  22. the excess ______ within the interstitial space enters the _______ capillaries an is returned to the blood circulation via _______ at the junction of the subclavian and jugular veins
    • filtered fluid
    • lymphatic
    • thoracic ducts
  23. what is the main factor that determines body fluid volume
    the extent of urinary NaCl loss
  24. what is the main factor that determines body fluid osmolarity
    the extent of urinary water loss
  25. what are the functions of the kidneys
    • regulation of blood pH
    • regulation of fluid and electrolyte balance: BP and blood volume
    • excretion of metabolic waste products: creatine, urea, uric acid, bilirubin, drugs or drug metabolites
    • hormone production: renin, erythropoietin
    • vitamin D production for calcium homeostasis
    • ammoniagenesis: increases in acidotic states to facilitate H+ buffering
    • gluconeogenesis during starvation
  26. in the kidney, what is located near the center of the medial border
    renal hilum (blood and lymph vessels, the ureter, and nerves enter/exit the kidney here)
  27. this is the most superficial tissue layer surrounding the kidney
    renal fascia
  28. this is a mass of fatty tissue surrounding each kidney that lies deep to the renal fascia, and it protects and holds the kidney firmly in place within the abd cavity
    adipose capsule
  29. this is the deepest layer surrounding the kidney parenchyma, it maintains the kidneys shape, and serves as a barrier against trauma
    renal capsule
  30. most renal nerves are _______ that regulate blood flow through the kidneys
  31. what insures adequate blood flow and glomerular filtration during "tonic" or resting sympathetic nervous system input
    intrarenal mechanisms
  32. this extends from the renal capsule to the bases of the renal pyramids, extends into spaces between renal pyramids as renal columns, and is smooth textured
  33. how many renal pyramids are within the medulla of the kidney
  34. within the medulla of the kidneys, what part of the renal pyramid contacts the cortex
    wide end (base)
  35. within the medulla of the kidneys, what part of the renal pyramid is the renal papilla
    narrower end (apex)
  36. this consists of a single renal pyramid, it overlies the area of the renal cortex, and one-half of each adjacent renal column
    renal lobe
  37. how many minor calyces does each kidney contain
  38. each calyx of the kidney receives what
    urine from the papillary ducts of one renal papilla and delivers it to a major calyx
  39. what receives urine from the minor calyces
    major calyces
  40. how many major calyces are in each kidney
  41. what receives urine from the major calyces
    renal pelvis
  42. within the renal pelvis, what transports urine from the renal pelvis to the bladder
  43. these are cavities within the kidney that often contains adipose tissue
    renal sinuses
  44. what contains part of the renal pelvis, the calyces, and branches of the renal blood vessels and nerves
    renal sinuses
  45. what are the functional units of the kidneys
  46. clinical signs of kidney dysfunction usually are not observed until when
    75% of nephrons are damaged
  47. what are the major structures of the nephron
    • renal corpuscle
    • renal tubules
  48. within the nephron, this is the location where blood plasma is filtered
    renal corpuscle
  49. within the nephron, this is the location through which filtered fluid passes
    renal tubules
  50. how are the nephrons divided
    into cortical nephrons and juxtamedullary nephrons
  51. what contains the short loops of henle, and has the renal corpuscles are located in the upper and middle regions of the cortex
    corical (superficial) nephrons
  52. this contains the long loops of henle, and the renal corpuscles are located deep in the cortex
    juxtamedullary (deep) nephrons
  53. what is the renal blood flow in the adult
    ~ 1200ml per minute
  54. these are branches from the abdominal aorta and transport oxygenated blood to each kidney
    right and left renal arteries
  55. the blood in the right and left renal arteries is filtered where
    at the glomerulus
  56. these transport filtered, deoxygenated blood to the inferior vena cava, and the blood returns to the lungs for re-oxygenation
    renal veins
  57. this is the location where renal filtration takes place
    the renal corpuscle
  58. what are the components of the renal corpuscle
    • glomerulus
    • Bowmans capsule
  59. within the renal corpuscle, this is a capillary system, has a fenestrated endothelial cell layer, and contains a basement membrane and mesangial cells
  60. what underlies the endothelium of the glomerulus
    basement membrane
  61. this supports the glomerulus structurally and can contract and reduce the capillary surface area available for filtration
    mesangial cells
  62. within the renal corpuscle, this is a mitt-like structure surround the entire glomerulus
    bowmans capsule
  63. within the bowmans capsule, this is a cavity that receives filtered fluid from the glomerular capillaries
    bowmans space
  64. within the bowmans capsule, this is a single epithelial cell layer surrounding the glomerular capillaries
  65. within podocytes, these are foot-like projections
  66. what forms the visceral layer of Bowmans capsule
  67. blood flows through one _____ into each glomerulus
    afferent arteriole
  68. one _____ transports blood out of each glomerulus
    efferent arteriole
  69. blood flowing from the glomerulus enters capillaries surrounding what
    renal tubules
  70. what are the capillaries that surround the renal tubules
    • cortical peritubular capillaries
    • vasa recta
  71. within the capillaries of the renal tubules, what receives blood from the efferent arterioles, and surround the part of the renal tubular system located in the cortex
    cortical peritubular capillaries
  72. within the capillaries of the renal tubules, what receives blood from the efferent arterioles, and surround the part of the renal tubular system located in the medulla
    vasa recta
  73. this is where filtrate enters the bowman space then flows through the renal tubular system where the processes of tubular reabsorption and tubular secretion occurs
    renal tubule system
  74. what are the renal tubules in sequence
    • proximal convoluted tubule
    • descending loop of henle
    • ascending loop of henle
    • distal convoluted tubule
    • collecting ducts
  75. within the renal tubules, where does most solute and water reabsorption occur
    proximal convoluted tubule
  76. within the renal tubules, this area is impermeable to solutes (Na+, K+, and urea), permeable to water, and concentrates the tubular fluid
    descending loop of henle
  77. within the renal tubules, this area is impermeable to water, permeable to solutes (Na+, K+, Cl-, and urea in the thin portion only), and dilutes tubular fluid
    ascending loop of henle
  78. within the renal tubules, this area modifies electrolyte concentration within the tubular filtrate
    distal convoluted tubule
  79. within the renal tubules, these areas receive tubular filtrate from the nephrons, is the site of free water absorption through aquaporins, is the final site for H+ or HCO3 secretion, and is where the urine flows through papillae into the minor calyces
    collecting ducts
  80. what are the 3 processes of urine formation
    • glomerular filtration
    • tubular reabsorption
    • tubular secretion
  81. within urine formation, what is the process of filtration that yields filtrate
    glomerular filtration
  82. within urine formation, when does a substance get transported from the tubular filtrate into the blood in peritubular capillaries and vasa recta
    tubular reabsorption
  83. within urine formation, when does a substance get transported from the blood in peritubular capillaries and vasa recta into the tubular filtrate
    tubular secretion
  84. the is the area where the distal convoluted tubule nearly contacts its parent glomerulus
    juxtaglomerular apparatus
  85. what does the juxtaglomerular apparatus contain
    • juxtaglomerular cells
    • macula densa cells
  86. within the juxtaglomerular apparatus, these form part of the wall of the distal convoluted tubule
    macula densa cells
  87. within the juxtaglomerular apparatus, this is located near the afferent arteriole serving the "parent" glomerulus
    macula densa
  88. what are the functions of the macula densa cells
    • sense flow of tubular filtrate and Na+ delivery to the distal nephron
    • participate in autoregulation of plasma fow and glomerular filtration rate
    • participate in regulating renin release from juxtaglomerular cells adjacent to the afferent arteriole
    • receive input from the sympathetic nervous system
  89. what are the major concepts of the glomerular filtration
    • filtration fraction
    • filtration membrane
    • glomerular filtration pressures
    • glomerular filtration rate
    • glomerular filtration regulation
  90. this is the fraction of blood plasma in kidney afferent arterioles that becomes filtrate
    filtration fraction
  91. what are the average daily volumes of glomerular filtrate for men and women
    • 180 liters (males)
    • 150 liters (females)
  92. this is a "leaky" barrier, it permits filtration of water, solutes, and very small protein molecules, and it prevents filtration of most plasma proteins, blood cells, and platelets
    filtration membrane
  93. what are the 3 layers of the filtration membrane
    • glomerular capillary endothelium
    • glomerular capillary basement membrane
    • slit membrane
  94. within the filtration membrane, this areas permits all solutes in plasma to exit glomerular capillaries, and prevents filtration of platelets and blood cells
    glomerular capillary endothelium
  95. within the filtration membrane, this area prevents filtration of larger plasma proteins
    glomerular capillary basement membrane
  96. within the filtration membrane, this area permits passage of molecules <0.006 - 0.007 microns, and less than 1% of plasma albumin passes through here
    slit membrane
  97. what are the exceptions for when filtration through glomerular capillaries is similar to filtration through other capillaries in the body
    • surface area available for glomerular filtration is very large and is regulated by contraction and relaxation of mesangial cells
    • the filtration membrane is thin and porous
    • glomerular capillary blood pressure is high
  98. filtration through the glomerulus is a product of what
  99. three starling forces determine what
    net filtration pressure
  100. glomerular filtration occurs when the net filtration pressure is what
  101. this pressure forces fluid out of the glomerular capillaries and promotes filtration
    glomerular capillary hydrostatic pressure
  102. glomerular capillary hydrostatic pressure is a product of ______ arteriolar diameter and "upstream" _____ artery, _____ artery, and _______ blood pressure
    • efferent
    • systemic
    • renal
    • afferent arteriole
  103. normal pressure of glomerular capillary hydrostatic pressure is what
    ~55 mmHg
  104. what are the intrarenal and extrarenal mechanisms that regulate afferent and efferent arterial diameter
    • circulating hormones
    • tubuloglomerular feedback
    • neural input
    • myogenic regulation
  105. this is pressure exerted by plasma proteins that draws fluid into glomerular capillaries, and it opposes filtration
    glomerular capillary oncotic pressure
  106. what is the normal pressure of glomerular capillary oncotic pressure
    ~30 mmHg
  107. what pressure is synonymous with interstitial fluid hydrostatic pressure, and pressure within here opposes filtration
    bowmans space hydrostatic pressure (capsular hydrostatic pressure)
  108. what is the normal back pressure of bowmans space hydrostatic pressure
    ~15 mmHg
  109. this pressure promotes filtration of fluid into the bowmans space, and in a healthy person the amount of protein in bowmans space is negligible so this pressure is not significant
    bowmans space oncotic pressure
  110. this reflects the size and number of functioning nephrons
    filtration coefficient (Kf)
  111. when is glomerular filtration adversely affected
    if the membrane surface is reduced by a disease process
  112. a net filtation of _____ causes a normal volume of blood plasma to filter from the ______ capillaries into the _____
    • ~10mmHg
    • glomerular
    • bowmans space
  113. this is the measurement of plasma volume that is filtered across all functioning glomeruli in both kidneys per minute
    glomerular filtration rate
  114. what is the average adult GFR
    • 125 ml/min (males)
    • 105 ml/min (females)
  115. what occurs if the GFR is too high
    useful substances are excreted in urine
  116. what occurs if the GFR is too low
    certain waster products may not be adequately excreted
  117. GFR is directly related to what
    to the pressures that determine net filtration pressure
  118. when is the GFR nearly constant
    when the mean (systemic) arterial blood pressure is 80-180 mmHg
  119. what are the factors that decrease or stop filtration
    • ↓ GBHP: MAP <80mmHg due to a hemorrhage
    • ↑ CHP: blockage of one or both ureters
    • ↓ Kf: disease affecting glomerular filtration
  120. what is the most reliable test of renal function
    routine measurement of GFR
  121. what is the GFR measurement based on
    the principle of renal clearance
  122. what is the plasma volume cleared of a substance per unit time called
    renal clearance
  123. what are the 2 ways clinical labs measure GFR
    • inulin clearance test
    • creatinine clearance test
  124. what occurs when GFR decreases
    • less creatinine is filtered and excreted
    • the plasma creatinine concentration increases
  125. in renal clearance, what test is routinely used to measure an endogenous waste substance produced by muscle metabolism
    creatinine clearance test
  126. which test is used to determine the extent of nephron damage in pts with known renal dz, determines the feasibility of administering certain medications which may build up to dangerous blood levels if GFR is significantly decreased, and is used to monitor effectiveness of tx designed to prevent further nephron damage
    creatinine clearance test
  127. GFR is regulated by changes in blood flow to glomeruli via what
    • intrarenal feedback systems
    • hormone action
    • renal sympathetic nerve activity
    • circulating vasoactive substances
  128. the 2 mechanisms of this are known as renal autoregulatory processes
    intrarenal feedback systems
  129. what are the 2 mechanisms of the intrarenal feedback systems
    • myogenic mechanism
    • tubuloglomerular feedback mechanism
  130. within the myogenic mechanism, the renal arteries and _____ respond directly to ______ systemic blood pressure by ______
    • afferent arterioles
    • increased
    • constricting
  131. which mechanism of the intrarenal feedback system involves the macula densa of the JGA
    tubuloglomerular feedback mechanism
  132. what are the flow rates of the tubuloglomerular feedback mechanism
    • decreased filtrate flow rate
    • increased filtrate flow rate
  133. which flow rate of the tubuloglomerular feedback mechanism is where less filtrate volume flows past the macula densa, more Na+ reabsorption from the filtrate occurs, the macula densa senses decreased Na+ concentration of filtrate in the DCT, and the afferent arterioles dilate in response to NO release from JG cells
    decreased filtrate flow rate
  134. which flow rate is where increased Na+ concentration in the DCT is sensed by the macula densa, afferent arterioles constrict when NO secretion from the JG cells is inhibited, and increased tubular flow causes macula densa cells to secrete adenosine or ATP causing constriction of afferent arterioles
    increased filtrate flow rate
  135. the myogenic and tubuloglomerular feedback mechanisms regulate GFR on a minute-by-minute basis and maintain GFR when the MAP is what
    80-180 mmHg
  136. this is activated in response to decreased renal blood flow
    renin-angiotensin-aldosterone system
  137. what detects decreased blood pressure in the renal vascular system and directly stimulate renin secretion by JG cells adjacent to afferent arterioles
  138. the RAAS is activated to _____ systemic BP, but the GFR is being _____ at the same time
    • increased
    • reduced
  139. this is released from cardiac myocytes within the right atrium in response to increased blood volume
    atrial natriuretic peptide
  140. circulating atrial natriuretic peptide _____ afferent arterioles and ______ efferent arterioles
    • dilates
    • constricts
  141. what occurs when the GFR is increased by atrial natriuretic peptide
    • increased Na+ and water excretion
    • decreased blood volume
  142. decreased systemic BP stimulates sympathetic nerves to secrete _____ and _____
    • norepinephrine
    • epinephrine
  143. what overrides intrarenal mechanisms reducing renal blood flow and GFR
    intense sympathetic nerve activity
  144. what are the intrarenal prostaglandins
    PGE2 and prostacycline (PGI2)
  145. these act as paracrine hormones causing mesangial cell relaxation
    intrarenal prostaglandins
  146. most reabsorption of solutes and water occurs here
    proximal nephron
  147. the fine-tuning of fluid and electrolytes occurs here
    distal nephron
  148. what is known as obligatory water reabsorption
    approximately 65-70% of water reabsorption into peritubular capillaries occurs in the PCT primarily following Na+ reabsorption
  149. which area of the PCT is where the Na+ an water enters the tubular cells via secondary active cotransport with glucose, amino acids, organic acids, and phosphates, and Na+/H+ antiporters facilitate H+ secretion into the filtrate
    early PCT
  150. which area of the PCT is where the Na+/H+ antiporters continue to secrete H+ and reabsorb Na+, and Cl- enters tubule cells through the apical antiporters
    late PCT
  151. with Na+ reabsorption, which area of the LOH is impermeable to Na+
  152. which area of the DCT is where Na+ and Cl- are transported into tubule cells by Na+-Cl- cotransporters
    early DCT
  153. which area of the DCT is where Na+ and K+ channels allow passive Na+ reabsorption and K+ secretion
    late DCT
  154. within the late DCT, what influences the increase of channel numbers
  155. in the collecting duct, passive Na+ reabsorption and K+ secretion occurs through Na+/K+ channels under the influence of what
  156. what becomes the rate limiting step for reabsorption of glucose
    capability of Na+/glucose carriers to transport glucose
  157. the capability of Na+/glucose carriers to transport glucose becoming the rate limiting step for reabsorption is known as what
    transport maximum
  158. what occurs when the filtered load of glucose is high
    • indicates that the plasma glucose concentration is abnormally elevated
    • excess glucose enters the filtrate
    • Na+/glucose carries become saturated (TM is exceeded)
    • not all glucose is reabsorbed
    • glucosuria occurs
  159. the renal threshold for glucose is exceeded when plasma glucose concentration is what
    250 mg/dl or higher
  160. filtered HCO3- in H+ secreted from tubule cells form CO2 and H2O where
    tubular lumen