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2012-05-07 21:33:51
urinary system

urinary system
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  1. List the fxns of the urinary system:
    • filter blood plasma, excrete toxic metabolic wastes
    • regulate blood volume, pressure, and osmolarity by regulating water output
    • regulate electrolyte, pH balance
    • secrete hormone erythropoietin, RBC production
    • clear hormones/drugs from the blood
    • detoxify free radicals
  2. describe the metabolic wastes and nirtogenous wastes:
    • metabolic wastes: a wastes substace produced by the body
    • nitrogenous wastes: among the most toxic of out metabolic wastes, ex urea (by product of protein catabolism)
    • blood urea nitrogen (BUN): the level of nitrogenous wate in the blood, normal is 10 - 20 mg/dL

    protein catabolism by products: ammonia, urea, uric acid, creatinine
  3. describe excretion that is carried out by 4 systems of the body:
    • excretion: process of esparating wastes from the body fluid and eliminating them
    • carried out by 4 systems
    • respiratory system: carbon dioxide, small amounts of other gases and water
    • integumentary system: water, inorganic salts, lactic acid, urea in sweat
    • digestive system: food residue, water, salts, carbon dioxide, lipids, bile, cholesterol, metabolic wastes
    • urinary system: metabolic wastes, toxins, drugs, hormones, salts, hydrogen ions, water
  4. describe the anatomcial features of the kidney:
    • weighs 150g
    • oblong size
    • T12-L3 retroperitoneal location
    • Right kidney is slighty lower than the Left
    • Nephrons, medulla cortex
  5. trace the path of blood flow through the kidney:
    • each kidney is supplie by the renal artery arising from the aorta
    • divides into a few segmental arteries
    • further divides into interlobar arteries,
    • travel between the pyramids
    • branches again form the arcuate arteries, which travel along the base of the pyramids
    • then these give rise to the interlobular arteries
    • afferent arterioles , leads to the glomerulus
    • blood leaves the glomerulus by the efferent arterioles, which then lead to the pertiubular capillaires, then to the interlobular veins, arcuate veins, interlobar veins, and renal vein, there are NO segmental veins

    2 sets of arterioles, 2 sets of capillaries - coritcal nephron ( peritubular capillaries ) and the juxamedullary nephron ( vasa recta)
  6. describe the structure of the renal corpsucle of the nephron:
    • renal corpuscle: consists of the glomerulus and the glomerular (Bowman) capsule
    • glomerular (Bowman) capsule: 2 layers - parietal (outer) layer - simple squamous epithelium, and visceral (inner) layer that consists of podocytes
    • capsular space: separtes the 2 layers by a filtrate collector

    fxn: filters the blood plasma
  7. describe the strcutre of a nephron and explain the physiological function of each nephron component:
    • renal tubule: a duct that leads away from the glomerular capsule
    • Fxn: convert the filtrate into urine
    • proximal convoluted tubule (PCT): arises from glomerular capsule, a great deal of absorption occurs here
    • nephron loop (loop of Henle): long U shaped protion, descending and ascending limb, thick segment engaged in active transports, and thin segments is permable to water
    • distal covoluted tubule (DCT): the end of the nephron
    • collecting duct: receives fluid from the DCT of several nephrons
  8. distinguish between the cortical and justameduallary nephrons on the basis of location, strcutrue and fxn:
    • cortical nephrons
    • location: beneath the renal capsule, close to the kidney surface, in cortex
    • strcutre: short nephron loops, or none
    • fxn:

    • juxtamedullary nephrons:
    • location: in the medulla
    • structure: long nephron loops
    • fxn: maintaining an osmotic gradient inthe medulla that helps the body conserve water
  9. Trace the flow of urine though kidney and out of the body:
    • glomerular capsule
    • proximal convoluted tubule
    • nephron loop
    • distal convoluted tubule
    • collecting duct
    • papillary duct
    • minor calyx
    • major calyx
    • renal pelvis
    • ureter
    • urinary bladder
    • urethra
  10. identify the 3 basic steps/stages of urine formation in the nephron:
    • converts blood plasma to urine
    • glomerular filtration, tubular reabsorption, tubular secretion, and water conservation
    • glomerular filtrate: fliud in capsular space, similar to blood plasma, NO PROTEINS
    • tubular fluid: fluid from PCT to DCT, substaces are added/removed by tubules
    • urine: fluid in the collecting duct, little alteration
  11. describe the filtration membrane:
    • fenestrated endothelium of the capillary: large filtration pores, highly permeable, but small enough to exclude blood cells from filtrate
    • basement membrane: gel-like, small pores, excludes molcules larger than 8nm, and negatively charged particles
    • filtration slits: podocytes, allows molecules about 30nm wide between them

    • most molecules smaller than 3 nm can pass
    • molecules that can pass are: water, electrolytes, glucose, fatty acids, amino acids, mitrogenous wastes, and vitamins
    • molecules turned back: blood cells, plasma proteins, large anions, protein-bound minerals and hormones, most molecules >8nm in diameter
  12. describe how infections or trauma can affect the filtration membrane:
    • can allow albumin or blood cells to filter through
    • proteinuria (albuminuria): kidney disease, marked by the presence of protein (albumin) in the urine
    • hemauria: presence of blood in the urine
  13. describe the composition of glomerular filtrate:
    water electrolytes, glucose, fatty acids, amino acids, vitamins, urea, uric acid, creatinine
  14. describe the net filtration pressure and know how to calculate it:
    • high outward pressure, opposed by two inward pressures
    • BHP: blood hydrostatic pressure, a large inlet and small outlet
    • COP: colloid osmotic pressure, constant pressure everywhere
    • CP: capsular pressure, results from high rate of filtration and continual accumulation of fluid in capsule

    • how to calculate
    • BHP
    • - COP
    • - CP
    • = NFP net filtration pressure

    • ~20% fluid filtration
    • ~ 80% goes to peritubular capillaires
    • ~ 99 % reabsorbed after filtering
    • entire blood supply filtered 60x/day
  15. explain net filtration pressures's relationship to glomerular filtration rate:
    • GFR: the amount of filtrate formed per minute by the two kidneys combinded
    • adjusted by the changing pressure of the glomerular capillaires - vasoconstriction/dilation of afferent/efferent arterioles
    • an increase in PGC > increases NFP > increase GFR, too rapid to reabsorb the usual amout of water/solutes, output rise, dehydration and electrolyte loss
    • decreased GFR > reaborbs wastes that should be eliminated
  16. explain how GFR is regulated by renal autoregulation:
    • the ability of the nephrons to adjust their own blood flow and GFR with external (nervous/hormonal) control, enables them to maintain stable GFR despite changes in BP
    • myogenic mechanism: based on the tendency of smooth muscle to contract when stretched, when BP rises it strectchs afferent arteriole, mechansim constricts arteriole to prevent blood flow and changing GFR
    • tubolomerular feedback: glomerulus recvs feedback on the status of downstream tubular fluid, adjusts filtration to reg is compsition, nephron preformance, compensate flucutaions in BP, if GFR rises> increase flow tubular fluid + rate of Na+ reabsorption by the PCT > macula densa senses variation > secrete paracrine > JG cells contract afferent arteriole > reduces GFR
  17. explain how GFR is regulated by Sympathetic control:
    sympatheitc stimulation and adrenal epinephrine constrict the afferent arterioles, this reduces GFR, redirecting blood from kidneys to the heart, brain, skeletal muscles where is its needed
  18. describe the structure and fxn of the juxtaglomerular apparatus:
    • found at the end of the nephron loop where it comes into contact with afferent and efferent arterioles of renal copruscle
    • macula densa: epithelial cells on the side facing the aterioles
    • justaglomerular cells: smooth muscle cells, in afferent afteriles, when stimulated by macula they dilate or constrict afterioles, contain granules of renin, which are secreted in response to drop in blood pressure
    • mesangial cells: contstrict or relax glomerulus capillaries to regulate blood flow and GFR and phagocytize tissue debris
  19. explain how GFR is regulated by the renin- angiotensin - aldosterone mechanism:
    • decreased BP> decreased baroreceptor firing > increased SNS to JG cells to secrete renin
    • renin: acts on angiotensionogen, a protein in blood plasma, into peptid called angiotensin I
    • angiotensin-converting enzyme (ACE): converts angiotensin I into angiotensin II
    • angiotensin II: vasoconstrictor - (widespread), constrict efferent arterioles, enhances reabsorption of NaCl and water from nephron; stimulates aldosterone - promotes Na+ and water reabsorption; stimulates hypothalmus to secrete anitdiuretic hormone - promotes water reabsorption (thru thirst)
  20. explain the role of tubular reabsorption:
    the process of reclaiming water and solutes from teh tubular fluid and returing them to the blood, PCT
  21. Put the following vessels in order according to blood flow through the kidney:

    peritubular capillaries
    interlobar artery
    arcuate vein
    afferent arteriole
    segmental artery
    renal vein
    efferent arteriole
    • segmental artery
    • interlobar artery
    • afferent arteriole
    • glomerulus
    • effernt arteriole
    • peritubular capillaires
    • arcuate vein
    • renal vein
  22. Most of the fluid inside the nephron tubules is reabsorbed into the blood stream in the:

    thick segment of the nephron loop
    glomerular capsule
    proximal convoluted tubule
    collecting duct
    distal convoluted tubule
    proximal convoluted tubule
  23. Trace the flow of urine through the kidneys and out the body:

    collecting duct
    urinary bladder
    nephron loop
    renal pelvis
    glomerular capsule
    distal convoluted tubule
    proximal convoluted tubule
    • glomerular capsule
    • proximal convoluted tubule
    • nephron loop
    • distal convoluted tubule
    • collecting duct
    • renal pelvis
    • ureter
    • urinary bladder
    • urethra
  24. Using the following information, calculate the net filtration pressure: blood hydrostatic pressure = 73 mm Hg, colloid osmotic pressure = 30 mm Hg, capsular pressure = 21 mm Hg.

    64 mmHg
    124 mmHg
    16 mmHg
    22 mmHg
    82 mmHg
    22 mmHg
  25. Which of the following leads to increased secretion of aldosterone? Choose ALL that apply.

    drop in K+ concentration
    drop in blood pressure
    drop in Na+ concentration
    calcium deficiency
    • drop in blood pressure
    • drop in Na+ concentration
  26. Which of the following is not expected in a healthy person’s urine?

    sodium chloride
  27. Which of the following muscles is under conscious control?

    external urethral sphincter
    urogenital diaphragm
    internal urethral sphincter
    external urethral sphincter
  28. Water reabsorption in the proximal convoluted tubule happens by two routes. __________ absorption occurs by water channels called _____________.

    Transcellular; aquapumps
    Paracellular; aquafirs
    Infracellular; aquapumps
    Transcellular; aquaporins
    Infracellular; aquafirs
    Paracellular; aquaporins
    Transcellular; aquaporins
  29. Which of the following mechanisms is important for maintaining osmolarity in the renal medulla?

    renal autoregulation
    micturition reflex
    countercurrent exchange system
    juxtaglomerular apparatus
    juxtaglomerular apparatus
  30. The ______________ secrete(s) renin in response to _______________.

    juxtaglomerular cells; a drop in blood pressure
    macula densa; a drop in blood volume
    mesangial cells; a rise in blood pressure
    myogenic mechanism; increased Na+
    hypothalamus; a drop in renin
    juxtaglomerular cells; a drop in blood volume
  31. Tubular secretion moves substances from the _______ into the _________.

    nephron loop; distal convoluted tubule
    glomerulus; Bowman's capsule
    nephron loop; blood
    kidney; urinary bladder
    blood; nephron tubules
    blood; nephron tubules
  32. Homer has been chasing a space coyote through the desert and has become severely dehydrated. As a result, his daily urine volume is only 50 mL. What condition does Homer have?

  33. differentiate between paracellular and transcellular reabsorption:
    • paracellular: substances pass thur gaps between the cells, "next to", pass between tight junctions
    • molecules that can pass thru paracellular: H2O, urea, uric acid, Na+, K+, Cl-, Mg2+, Ca2+, P
    • transcellular: substances pass thru the cytoplasm and out of the base of the epithlial cells, "across"
    • types of transcellular reabsorption: symports, anitports, aquaporins
  34. Explain the mechanisms and sites of reabsorption of Na+:
    • symports: simultaneously bind Na+ and another solute such as glucose, amnio acids, or lactate to be transported thru the cell, diffusion
    • antiports: pulls Na+ into the cell while pumping H+ out of the cell into the tubular fluid, activated by angiotensin II, active transport
  35. summarize the mechanisms and sites of reabsorption of Cl-:
    • follow Na+ because they are electrically attracted to it
    • antiports: cell membrane absorbs Cl- in exchange for other anions that they eject into the tubular fluid, active transport
    • symports: Cl- and K+, diffusion
    • paracellular route
  36. summarize the mechanisms and sites of reabsorption of K+:
    paracellular: diffusion, along with water
  37. summmarize the mechanisms and sites of reabsorption of H2O:
    • reabsorbed by the PCT
    • paracellular: follows solutes by osomsis, diffusion
    • transcellular: water channels called aquaporins, enables water to enter at the apical sufrace, and leave to return to the blood at the basolateral surface
  38. summarzie the mechanisms and sites of reabsorption of glucose:
    sodium - glucose transporters (SGLTs): symports in which glucose is cotransported with Na+, removed from basolateral surface by facilitated diffusion
  39. summarzie the mechansims and site of absorption of urea:
    paracellular: passes with water, diffusion, solvent drag
  40. define glycosuria and explain its relationship to the concept of transport maximum:
    • there is a limit to the amount of solute that the renal tubule can reabsorb because there are limited # of transport proteins in the plasma membranes
    • transport maximum (TM): transporters are saturated
    • each solute reabsorbed has its own TM
    • Glucose: when blood glucose levels rise, glucose is filtered faster than the renal tubules can reabsorb it, excess passes thru the urine
    • glycosuria: excess glucose in the urine, diabetes mellitus

    if all thransporters are occupied, then no reabsorption, flows into urine
  41. explain the role of tubular secretion and summarize the sites of secretion of K+, H+, urea, and drugs toxins:
    • a process in which the renal tubules extracts chemicals form teh capillary blood and secretes them into the tubular fluid
    • waste removed: urea, uric acid, bile acids, ammonia and creatinine secreted into tubules
    • drugs/toxins: secretion of pollutants, morphoine, penicillin, aspirin,
    • H+: secretino regulates the pH of body fluids
  42. describe the fxn, mechanism of action, site of action, and effects of hormones that regulate Na+ and water reabsorption (aldosterone):
    • Na+: aldosterone: "salt retaining" hormone, secreted when blood Na+ concentration falls, increases salt reabsorption
    • K+ secretion: aldosterone: secreted when blood K+ concentration rises
    • net affect of aldoseterone: body retains NaCl and water, urine volume is reduced, and the urine has an elevated K+ concentration
    • renal targets: nephron loop, DCT, and CD
  43. describe the fxn, mechanism of action, site of action, and effects of hormones that regulate Na+ and water reabsorption (ANP):
    • ANP: artrial natriuretic peptides, secreted by the heart in response to high blood pressure, stimulated by stretch of right atrium
    • result: excretion of more salt and water in the urine, reducing blood volume/pressure
    • a. dilate afferent arteriole and constrict efferent arteriole, increase GFR
    • b. inhibit renin adn aldosterone secretion
    • c. inhibit ADH and its action on the kidney
    • d. inhibit NaCl reabsorption by collecting duct
    • renal targets: afferent and efferent arterioles, CD
  44. describe the fxn, mechanism of action, site of action, and effects of hormones that regulate Na+ and water reabsorption (autidiuretic hormone):
    • ADH: secreted by hypothalmus in response to dehydration, and rising blood osmolarity
    • result: makes collecting duct more peremable to water, reduces urine volume, increases concentration
    • renal targets: collecting duct
  45. summarize how ANP aids regulation of Na+ and H2O reabsorption affects blood volume and blood pressure:
    blood volume decreases > blood pressure decreases > aterial stretch decreases > ANP decreases > aldosterone from adreanal cortext increases > Na+ reabsorption in collecting duct increases > Na+/H2O excretion decreases > blood volume/pressure increases
  46. summarize how renin/aldosterone aids regulation of Na+ and H2O reabsorption affects blood volume and blood pressure:
    blood volume decrease > blood pressure decreases > NaCl flow past macula densa decreases > renin secretion increases > angiotensin I & II increases/ diameter of arterioels decrease > aldosterone from adrenal cortex increases/ GFR decreases> Na+ reabsorption in collecting ducts increases > Na+/H20 excretion decreases > blood volume/blood pressure increases
  47. summarize how SNS aids regulation of Na+ and H2o reabsorption affects blood volume and blood pressure:
    blood volume decrease > blood pressure decreases > barorecptor firing decreases/ > sympathetic activity increases/ ADH increases > renin secretion increases > diameter of afferent arterioles decrease > GFR decrease > Na+/H2o excretion decreases > blood volume/pressure increases
  48. summmarize how ADH aids regulation of Na+ and H2O reabsorption affects blood volume and blood pressure:
    blood volume decreases > blood pressure decreases> baroreceptor firing decreases > ADH increases > diamter of afferent arterioles decreses/ H2o absorption increases > GFR decreases > Na+/H2o excretion decreases > blood volume/blood pressure increases
  49. describe how the counter current multiplier system works and explains its role in urine formation:
    • the ablility of the CD to concentrate urine depends on the osmotic gradient of the renal medulla
    • countercurrent multiplier: contiunally recaptures salt and returns it toe the deep medually tissue, based on fluid flowing in two opposite directoins in two adjacent tubules

    • 1. more salt is continually added by the PCT
    • 2. the higher the osmolarity of the ECF, the more water leaves the descending limb by osmosis
    • 3. the more water that leaves the descending limb, the saltier the fluid is that remains in the tubule
    • 4. the saltier the fluid in the ascending limb, the more salt the tubule pumps into the ECF
    • 5. the more salt that is pumped out of the ascending limb, the saltier the ECF is in the renal medulla

    **Negative feedback
  50. describe the typical physical and chemical characteristics of urine:
    • appearance: colorless to amber, yellow due to the breakdown of hemoglobin, clear, cloudy suggests infection, contaminatin, or too many crystals
    • odor: distincitve, can be altered by food or infection
    • specific gravity: 1.001 when it is very diluted, 1.028 when it is very concentrated
    • osmolarity : 50 mOsm/L if person is hydrated, to 1,200 mOsm/L if person is dehydrated
    • pH: ususally 6.0 (ranging from 4.5 to 8.2)
    • chemical composition: urea, sodium chloride, potassium chloride, creatinine, uric acid, phosphates, sulfates, calcium, magnesium, bicarbonate
  51. recognize abnormal phyusical and chemical characteristics of urinalysis:
    glucose, free hemoglobin, albumin, ketones, or bile pigments, WBC, RBC, protein
  52. define diuretic and explain the mechansim by which diruetics like caffeine and alcohol affect urine output:
    • diuretic: any chemical that increases urine volume
    • caffine: act by increaseing glomerular filtration by which dilates the afferent arteriole
    • alcohol: reduces tubular reabsorption of water, inhibits ADH secretion, reduces reabsorption in collecting ducts
  53. explain the difference between diabetes mellitus and diabetes insipidus in terms of the mechanism by which they cause diuresis/polyuria:
    • polyuria: results from a high concentration fo glucose in the renal tubule
    • diabetes mellitus: osmotic diuresis - waters passes in the urine, "passes thru", test for sweetness, failure to reabsorb all glucose, not enough symport channels, increase glucose for increse water from plasma to tublues - more water excreted by osmosis
    • diabetes insipidus: ADH hyposecreteion, collecting duct does not reabsorb much water, so more water passes thru urine, passing thru tasteless, the urine contains no glucose
  54. define/calculate renal clearnace and understand how renal clearance is used to assess renal fxn:
    renal clearance: the volume of blood plasma from which a particular waste is completely removed in 1 min, measures elimiation efficiency

    RPC = U(urea concentration in urine)x V (rate of urine output) / P (urea concentation in plasma)

    • If RPC < less than GFR = substance reabsorbed
    • if RPC > greater than GFR = substance secreted

    • normal: 60ml of blood plasma cleared of urea/min, if normal GFR of 125 ml/min then
    • 60/125 = 48% of urea clearance, suficient to maintain safe levels of urea in blood
  55. explain how inulin and creatinine cleareance are used in determining GFR:
    • to measure GFR ideally requires a substance that is not secreted or reabsorbed at all, so that all of it in the urine gets there by glomerular filtration:
    • inulin: filtered by glomerulus, remains in renal tubules and apprears in the urine, not reabsorbed or secreted, must be injected
    • creatinine: small but acceptable error of measurement, easier than injection, slightly secreted
  56. describe the anatomy of urine sotrage and elimination:
    • ureters: funnels urine into the uretere
    • urinary bladder: detrusor muscle - smooth muscle, rugea
    • urethra: conveys urine out of the body
    • internal urethral sphincter: - compresses the urethra and retains urine in the bladder, smooth muscle
    • external uretheral sphincter: skeletal muscle, voluntary control over voiding urine
  57. compare and contrast the structure and fxn of the male and female urethra:
    • male urethera: 18 cm long, prostate gland
    • female urethra: 3 to 4 cm long
  58. describe the events in the mactrurition reflex including neural control:
    • involuntary micturition reflex
    • 1. stretch receptors detect filling of bladder, transmit affernt signals to spinal cord
    • 2. singnals return to the bladder from spinal cord segments S2 and S3 via parasympathetic fibers in the pelvic nerve
    • 3. efferent signals excite detrusor muscle
    • 4. efferent signals relax internal urethral sphincter. Urine in involunatarily voided if not inhibited by brain

    • voluntary control
    • 1. micturition center in pons recives signals from stretch receptors
    • 2. if it is timely to urinate, pons returns signals to spinal interneurons that excite detrusor and relax internal sphincter. urine is voided
    • 3. if it is timely to urinate, singals to pons cease and external urethra sphincer relaxes. urine is voided
  59. describe the muscles used in micturition and describe its innervation:
    • detrusor (smooth muscle)
    • type: parasympathetic (causes contration)
    • during filling: inhibited
    • during micturition: stimulated

    • internal urethral sphincter
    • smooth muscle
    • type: sympathetic (causes contraction)
    • during filling: stimulated
    • during micturition: inhibited

    • external urethral sphincter
    • skeletal muscle
    • type: somatic motor (causes contraction)
    • during filling: stimulated
    • during micturition: inhibited
  60. which of the following is NOT a fxn of the urinary system?

    A. regulation of blood volume and blood pressure
    B. regulation of blood pH and osmolarity
    C. regulation of blood glucose concentration
    D. regulation of red blood cell production by secretion of erythropoietin
    C. regulation of blood glucose concentration
    (this multiple choice question has been scrambled)
  61. the movement of fluid and solutes from the nephron tubules into the peritubular capillairies is :

    A. glomerular filtration
    B. secretion
    C. reabsorption
    D. excretion
    C. reabsorption
    (this multiple choice question has been scrambled)
  62. if blood hydrostatic pressure is 70 mmHg, capsular hydrostatic presure is 30 mmHg, and colloid osmotic pressure of the blood is 10 mmHg, then net filtration pressure is:

    A. 90 mmHg
    B. 60 mmHg
    C. 30 mmHg
    D. 110 mmHg
    E. 50 mmHg
    C. 30 mmHg
    (this multiple choice question has been scrambled)
  63. constriction of the afferent arteriole directly causes a/an:

    A. increase in the tubular secretion rate
    B. increase in the golmerular fitration rate
    C. decrease in the glomerular filatration rate
    D. decrease in the tubular reabsorption rate
    C. decrease in the glomerular filtration rate
    (this multiple choice question has been scrambled)
  64. most nephrons in the kidney are:

    A. juxtaglomerular nephrons, which have long nephrons loops
    B. cortical nephrons, which have short nephron loops
    C. peritubluar nephrons, which have long nephron loops
    D. juxtamedullary nephron, which have short nephron loops
    B. cortical nephrons, which have short nephron loops
    (this multiple choice question has been scrambled)
  65. the retention of H2o occurs in which part of the nephron?

    A. collecting duct
    B. distal convoluted tubule
    C. nephron loop
    D. proximal convuluted tubule
    C. nephron loop
    (this multiple choice question has been scrambled)
  66. tubuloglomerular feedback is best described as vasoconstriction of the afferent arteriole in response to:

    A. increased stretch of the afferent arteriole
    B. increased fluid flow in the DCT
    C. angiotensin II
    D. SNS input
    B. increased fluid flow in the DCT
    (this multiple choice question has been scrambled)
  67. glucose is reabsorbed via:

    A. Na+/K+ ATPases
    B. acquaporins
    C. paracellular diffusion
    D. transporters
    D. transporters
    (this multiple choice question has been scrambled)
  68. which of the following substances is secreted?

    A. glucose
    B. Na+
    C. H+
    D. H2o
    C. H+
    (this multiple choice question has been scrambled)
  69. if blood volume drops, which of the following will occur to restore blood volume back to normal?

    A. the concentration of atrial natriuretic peptide (ANP) in the blood will increase.
    B. the concentration of angiotensin II in the blood will decrease
    C. PSNS activity to the kidneys will increase
    D. the concentration fo aldosterone in the blood will increase
    D. the concentration of aldosterone in the blood will increase
    (this multiple choice question has been scrambled)
  70. the osmolarity gradient inside the renal medulla exists because the ascending limb of the nephron loop is permeable to _____; and the descending limb is permeable to ______:

    A. H2o; NaCl
    B. NaCl, H2o
    C. H2o; glucose
    D. K+, H2o
    B. NaCl, H2o
    (this multiple choice question has been scrambled)
  71. antidiuretic hormone (ADH):

    A. increases the secretion of K+ into the distal convoluted tubules
    B. stimulates the increase of acquporins in the collecting ducts
    C. causes vasodilation of the afferent arteriole
    D. stimulates the release of renin from juxtaglomerular (JG) cells
    B. stimulates the increase of acquporins in the collecting ducts
    (this multiple choice question has been scrambled)
  72. which of the following characteristics is NOT normal for human urine?

    A. pH ~ 5.0
    B. yellow color
    C. specific gravity ~ 1.01
    D. osmolarity ~ 1900 mOsm/L
    E. no proteins present
    D. osmolarity ~ 1900 mOsm/L
    (this multiple choice question has been scrambled)
  73. the renal plasma clearance of inulin can be used to measure GFR because inulin is filtered:

    a. but not secreted nor reabsorbed
    b. and reabsorbed but not secreted
    c. and secreted but not reabsorbed
    d. and secreted and reabsorbed
    a. but not secreted nor reabsorbed
  74. the micturition relfex requires changes in input from the PSNS, SNS, and somatic nervous system to the organs of the urinary system. Neurons from the sympathetic nervous system (SNS) innervate which of the following?

    A. urethra
    B. detrusor muscle
    C. external urethral sphincter
    D. internal urethral sphincter
    D. internal urethra sphincter
    (this multiple choice question has been scrambled)
  75. aldosterone causes:

    A. increased Na+ and K+ reabsorption
    B. increased Na+ and K+ excretion
    C. increased Na+ reabsorption and increased K secretion
    D. decreased Na+ reabsorption and increased K+ secretion
    C. increased Na+ rebsorption and increased K+ secretion
    (this multiple choice question has been scrambled)