1.RENAL SYSTEM 1

2. Organs of the Renal SystemKidneysUretersUrinary bladderUrethraNot manystructures, butvery important!Figure 23.1a2 3. Functions of Urinary SystemRegulate electrolytes (K, Na, etc)Regulate pH in bloodRegulate blood pressureRegulate blood volume (removes excessfluid)Removing metabolic wastes Urea, uric acid, and creatinine This is the least important of the kidneys functions.You can survive for a few weeks without excretingwaste products in the urine, but hour by hour, theother functions are more important. 3 4. Relationship of the Kidneys toVertebra and RibsThey are retroperitonealand are located in theabdominal cavity.They are at the level ofT12 to L3, so they are atthe costal margin, and theribs protect them a little.Even though they areprotected by thoracic ribs,they are NOT in thethoracic cavity becausethey are below thediaphragm. Figure 23.1b 4 5. Position of the Kidneys with inthe Posterior Abdominal WallFigure 23.2a5 6. STRUCTURES WITHIN THE KIDNEYThe RENAL CAPSULE surrounds the kidney,made of dense fibrous connective tissue.A layer of adipose tissue surrounds the capsule,called PARARENAL FAT (ADIPOSE). Itcushions and protects.Around that is a connective tissue layer calledthe RENAL FASCIA, made of loose connectivetissue. It anchors the kidney to the surroundingperitoneum and abdominal wall. It is not verystrong; jumping up and down can cause tearing. 6 7. Vibration Platform Machine:No longer used in the USA because itdamages kidneys! 7 8. These are still around in gyms in other countriesbeware!8 9. Gross Anatomy of the Kidneys Renal cortex (Most superficial layer)Renal medullaRenal pyramids (drain into the calyx) Renal pelvisCalyx (drains into hylus ureter) Ureter9 10. Renal fascia Interlobar arteries Interlobular arteriesArcuatearteries 10 11. Internal Anatomy of the KidneysInterlobar arteryFigure 23.3b 11 12. Blood Supply to KidneyAORTA RENAL ARTERY SEGMENTAL ARTERIES INTERLOBAR ARTERIES ARCUATE ARTERIES (form arcs) INTERLOBULAR ARTERIESINTERLOBULAR VEIN ARCUATE VEIN INTERLOBAR VEINS SEGMENTAL VEINS RENAL VEIN INF. VENA CAVA 12 13. Internal Anatomy of the Kidneys Interlobar artery Figure 23.3b13 14. Microscopic Anatomy of the Kidneys Just like the functional unit of the lungs is the alveolus and the functional unit of the liver is the lobule, the functional unit of the kidney is the NEPHRON. Each kidney has about 1 million nephrons. Each one carries out all of the various functions of the kidneys. 14 15. Microscopic Anatomy of the NephronGLOMERULUS WITH A CAPSULEPROXIMAL CONVOLUTED TUBULELOOP OF HENLE DESCENDING LIMB Thick portion Thin portion ASCENDING LIMB Thick portion Thin portionDISTAL CONVOLUTED TUBULECOLLECTING DUCT15 16. Nephron16 17. Position of Nephron in KidneyFigure 23.4a 17 18. Glomerulus of a Nephron18 19. Juxtaglomerular Apparatus The distal end of therenal tubule passesnext to theglomerulus to formthe juxtaglomerularapparatus (juxtameans next to). The juxtaglomerularapparatus (JGA)consists of cellslocated in andaround theglomerulus and theglomerular capsule.19 20. Juxtaglomerular Apparatus If blood pressure istoo low, the JGAreleasesadenosine, whichcausesvasoconstriction ofthe afferent arteriole.This will slow thefiltration rate soless water is lost,and blood pressureincreases. 20 21. Juxtaglomerular Apparatus: Juxtaglomerular Cells if the blood pressure isstill too low afteradenosine has causedvasoconstriction, theJGA secretes thehormone renin . Renin causes moresodium to bereabsorbed, and waterfollows, so bloodvolume increases, soblood pressureincreases. 21 22. GLOMERULUSThe glomerulus is the first part of the nephron, where thefiltration occurs.The glomeruli are located only in the renal cortex.A glomerulus (ball of yarn) is a tuft of capillariessurrounded by a glomerular capsule (Bowmans capsule)made of simple squamous epithelium. The glomerulusfits in the capsule like a fist punched into anunderinflated balloon.The capsule collects the plasma from the arterioles anddrains it into the convoluted tubules, which empty into acollecting duct, which exits the body.The plasma is further filtered along the way.22 23. Glomerulus of a Nephron23 24. Normally at the end of the capillary bed youhave venuoles. But this is the only part of thebody that is different: here we have anotherarteriole, called the EFFERENT ARTERIOLE,which takes blood away from the glomerulus.The efferent arteriole drops down straight, nextto the Loop of Henle. While it is straight, it iscalled VASA RECTA (straight capillaries).There are capillaries that come off the vasarecta which surround the loop of Henle. Here,they are called peritubular capillaries. They thenleave the area to become the interlobular vein,which leaves the kidney.24 25. Nephron25 26. JuxtaglomerularapparatusEfferent arterioleAfferent arterioleBowmans capsule 26 27. FUNCTION OF THE NEPHRONBlood comes in from the AFFERENT ARTERIOLES.Plasma leaks out and enters the glomerular capsule.The plasma contains nutrients, waste products, etc. Asthe plasma moves through the proximal convolutedtubule, all of the nutrients, and most of the water, andmost of the ions are absorbed back out of the nephronsand into the blood.In the Loop of Henle, almost all of the rest of the waterand salt are removed blood.Everything that is not reabsorbed (the waste products)goes into the collecting duct and is excreted as urine.This is also how the water-salt balance is maintained, aswell as the acid-base balance.27 28. Nephron28 29. FUNCTION OF THE NEPHRONIn the distal convoluted tubule, the rest of thewater and salt are removed.The rest of the liquid goes into the collectingduct.The distal convoluted tubule and the collectingduct fine-tune the water and salt absorption andexcretion. If you are well hydrated, the water willbe allowed to leave as urine.If you are thirsty, the water will be absorbed.The purpose of the peritubular capillary bed is toabsorb these things from the nephron tubulesand put them back into the blood.29 30. Figure 23.530 31. Renal Corpuscle and theFiltration MembraneFigure 23.6c 31 32. Function of the Nephronhttp://www.youtube.com/watch?v=aQZaNX6 Tips for healthy urinary system:http://urology.about.com/od/infections/tp/5tipsf 32 33. DiureticsDiuretics are medicines that increase theamount of urine that is produced.People who have high blood pressure might beprescribed diuretics to decrease the bloodvolume.Alcohol is a diuretic and this is whatcontributes to the symptoms of a hangover.The best way to prevent a hangover afterdrinking is to consume a lot of water beforeyou go to bed.Caffeine is also a diuretic, so coffee andregular Coca-cola are diuretics. 33 34. HISTOLOGY OF THE NEPHRONPROXIMAL AND DISTAL CONVOLUTEDTUBULES This area absorbs nutrients, water, and salt.Only about 1% of the fluid filtered by thekidney actually becomes urine.LOOP OF HENLEThis is where water is reabsorbed. It islocated in the renal medulla.34 35. Urine ProductionFiltration filtrate of blood leaves kidneycapillariesReabsorption most nutrients, water, andessential ions reclaimedSecretion active process of removingundesirable molecules 35 36. Figure 23.9a 36 37. Collecting Duct (tubule)Receives urine from distal convolutedtubules, empties into ureter.Figure 23.4a 37 38. UretersThese are long tubes that connect the renalpelvis to the urinary bladderMUCOSA TRANSITIONAL EPITHELIUM (for expansion) LAMINA PROPRIA (has elastic tissue to recoil)MUSCULAR LAYER (smooth muscle)INNER CIRCULAROUTER LONGITUDINALADVENTITIA Provides protection, strength for organs, andattaches ureters to surrounding structures38 39. URINARY BLADDERThe histology of the urinary bladder isidentical to the ureter except the mucosallayer has folds called RUGAE, which allowfor expansion.The rugae have the same basic functionas transitional epitheliumaccommodating stretch as the bladderfills.You can hold up to one liter of urine,although at 500 ml, youll be dancing. 39 40. Urinary BladderRugae:allows forexpansion-A fullbladder isroughly thesize of a softball Figure 23.1440 41. URINARY BLADDERThe muscle layer around the urinarybladder is thicker than the ureters, and iscalled the DETRUSOR MUSCLE, whichcontracts to allow emptying of the urinarybladder.The function of the urinary bladder is justto store urine.41 42. Detrusor Muscle42 43. URETER entrance to BLADDERThe URETER enters in at the base of theurinary bladder, not the top.As the bladder fills, it presses down on theureters to prevent urine from backing upinto the kidneys. 43 44. BLADDERThe TRIGONE is a triangular area where the ureterscome in and the urethra goes out.Between the urethra and the urinary bladder are twosphincters:INTERNAL URETHRAL SPHINCTER: smooth muscleEXTERNAL URETHRAL SPHINCTER: skeletal muscle.Although it is primarily under voluntary control, it willcontract if the urine volume is too much.If the patient is in a coma or under anesthesia for a longtime, the internal sphincter will be closed, like when youare asleep, so a catheter is needed to open it to drainthe urine out. 44 45. 45 46. UrethraDrains the urine to the outside.Its histology is the same as the ureterFemales: 4cmMales 20 cm (varies with mood)Therefore, women (esp. little girls) aremore susceptible to UTI. 46 47. ProblemsURETHRITIS = infection and inflammationof the urethraPYELITIS= infection of the renal calyxesCYSTITIS = infection of the urinarybladder.CHOLEOCYTITIS = infection of the gallbladder 47 48. UREAUrea is a waste product of amino acidmetabolism.Remember, proteins are made of aminoacids, so when you break down proteins,you break them down into amino acids,and the waste product left over is urea.This is the main waste product in urine.Excessive proteins can cause kidneydamage, since they are acidic. 48 49. COLOR OF URINEWhen you urinate, it should be clear andcolorless with almost no yellow color.The more yellow the urine is, the moredehydrated you are.If the urine is very dark yellow, you areburning too much protein (as in fooddeprivation). This is often seen indiabetes.49 50. ProblemsKIDNEY STONESDevelop in the renal pelvis Stones are made out of a variety of things:uric acid, calcium, cystine (an amino acid), orcholesterol.They keep growing.50 51. KIDNEY STONESThey can block the ureter, causing the kidney toenlarge. As the kidney stretches, the capsulestretches, causing excruciating pain in cycles ofhours. As pressure builds up around the stone,urine can pass, and the kidney stone movesdown the urethra slowly.Symptomatic kidney stones may be pea sized orlarger (up to 1 inches).They get stuck in three places: Renal pelvis In the ureter as it bends over the common iliac artery In the urinary bladder at the trigone. 51 52. KidneyStones 52 53. 5 cm Kidney Stone Surgery53 54. Kidney stones get stuck in three places: Renal pelvis In the ureter as it bends over the common iliac artery In the urinary bladder at the trigone. 54 55. Wherekidney stones get stuckRenal pelvisUreter Common iliac arteryUrinarybladdertrigone55 56. 56 57. KIDNEY STONES TREATMENTULTRASOUND LITHOTRIPSYPut a powerful speaker on the outside of the kidney,sends a shock wave which the tissues absorb, but thestones shatter so the pieces can pass easier.STENT (1 foot long tube) in to keep the ureter open alongits entire length. Insert under general anesthetic,remove without.To help prevent kidney stones, drink enoughfluid so your urine stays clear and light colored.57 58. ULTRASOUND LITHOTRIPSY 58 59. 59 60. Kidney Stone Prevention60 61. ReynoldsUnwrapped.com offersFANTASTIC, inexpensive daily emailsubscriptions, where you can receive aHILARIOUS new cartoon every day, and it isa MARVELOUS idea for a UNIQUE gift foryour family and friends as well. That is how Ilearned about this...one of my fellow teachersgave me a subscription as a birthday present.He also has FUNNY greeting cards andBEAUTIFUL paintings for sale as well.You can also get reprints suitable for framing,or originals. Here is more info about his workand a YOUTUBE video.https://nccnews.expressions.syr.edu/?p=1151561 62. Other Kidney ProblemsNephritis: inflammation of the nephrons.Hydronephritis: excess fluid in the nephron.Glucose in the urine: indicates diabetes. 62 63. Kidney ProblemsThings can happen to the kidney: infection,excess proteins, pH change, blood pressuredrops, and can lead to kidney failure.Treatment for kidney failure is DIALYSIS, whichremoves blood, send it through a filter, andreturn it without the wastes. It is done threetimes a week, six hours a day. Ideally, theyneed a kidney transplant because the kidneyhas other functions as well.The brain, heart, and kidney are the only threeorgans in the body that have to get oxygen tosustain life.63 64. What is Renal Failure?Renal failure occurs when your kidneys stopworking.Our kidneys are very important to us becausewe use them to remove waste from our bodiesAnd our kidneys keep the balance of water andsalt in our body.If we are unable to regulate the water andmineral balance in our body, Renal Failure canbe life threatening. 64 65. Causes of Renal Failure1. Medication / Poison / Infection People with long term health problems are most at risk to have kidney problems from medication. - Antibiotics - Pain Medication - Blood Pressure Medicine - Dyes used in X-rays65 66. 2. Sudden drop in blood flow. - Heavy blood loss from an injury - A serious infection (Sepsis) - Severe Dehydration3. Blockage of fluid out of the Kidney - Kidney Stones - Tumor(s) - Enlarged Prostate Gland 66 67. Who is most likely to get Renal Failure?Kidney or Liver DiseaseDiabetesHigh Blood PressureHeart FailureObesityBone Marrow TransplantHeart or Belly Surgery 67 68. SymptomsVery little or no urine during urinationIf the body is unable to excrete potassium, the rising ofpotassium levels is associated with ventriculartachycardia and ventricular fibrillation. Lethal injectionsare excess potassium.Loss of appetiteAs waste accumulates, lethargy and fatigue becomeapparent to the point where mental function candecrease to coma.Body WeaknessBecause of low levels of erythropoietin produced byfailing kidneys they do not stimulate the bone marrowwhich leads to a decrease in red blood cells. This leadsto less oxygen throughout the body which leaves thebody unable to do work.68 69. SymptomsHigh Blood PressureBecause the kidneys can not deal with the rising acidlevels in the body, breathing becomes more rapid as thelungs attempt to blow off carbon dioxide to buffer theacid levels. In doing so, fluid can be deposited in thelungs possibly causing congestive heart failure.Swelling of the legs and feetNausea and or VomitingBack pain below the rib cage, (Flank Pain)Some people may not have any symptoms(asymptomatic)69 70. DiagnosisPatients can be diagnosed by undergoingblood and urine testsBlood UrineBUN Protein-Blood Urea NitrogenAbnormal presence ofCreatinineWhite and Red blood-Waste product levels cellsGFR Electrolytes-Glomerular Filtration Rate 70 71. DiagnosisPatients can also undergo an Ultrasound to see if there are any obstructions. 71 72. Treatment Treatments are based on the causeIssue Treatment- Blood Loss- Restore blood flow- Medication / Poison - Stop taking themedication or poison- Blockage- Remove or bypassblockage 72 73. Also, the person treating the patient willattempt to stop the buildup of waste in thebody. This may be done by dialysis.And the person treating the patient mayalso administer other medication toprevent the retention of excess fluid andminerals and prevent any further renaldamage.-lowering Phophorus levels-increase production of Red Blood Cells-regulate blood pressure with medication73 74. PreventionRegulate Blood PressureRegulate Sugar IntakeRegulate Protein IntakeOnce the kidney fails the only options aredialysis and transplantation. 74 75. Values Results NormalAPPEARANCECLEAR CLEARBACTERIA MODERATENEGBILIRUBIN NEGATIVE NEGCOLORAMBERStrawEPITHELIAL CELLS FEW FEWERYTHROCYTES3-5/HPF (High)0-2GLUCOSE NEGATIVE NEGHEMOGLOBINNEGATIVE NEGHYALINE CASTS0-4/LPF0-4KETONES 1+ NEGLEUKOCYTE ESTERASE1+ NEGLEUKOCYTES 6-10/HPF (High)0-2NITRITE NEGATIVE NEGPH6.5 4.5-8.5PROTEIN TRACENEGSPECIFIC GRAVITY1.0291.003-1.035UROBILINOGEN0.2150 mg/day (10-20mg per dL)-microalbuminuria= 30-150 mg/day (sign of early renal disease)Normal urinary proteins: albumin, serum globulins, proteins secreted by the nephron-Dipstick results: 1+ = 30 mg/dL 2+ = 100 mg/dL 3+ = 300 mg/dL 4+ = 1,000 mg/dLTypes: transient and persistent-Transient: temporary change, benign, self-limited (ex: orthostatic proteinuria that results from prolonged standing, but negative U/A after recumbency). -Positive test: Repeat U/A -Persistent has 3 types: glomerular, tubular, overflow-Glomerular: albumin primary urinary protein -Tubular: malfunctioning tubule cells- Overflow: Low MW Proteins overwhelm ability of tubules to reabsorb-Positive test: Perform 24-hour urinary protein excretion orspot urinary protein-creatinine ratio 80 81. Glucosuria Normal: almost completely reabsorbed inproximal tubule Criteria: occurs at approximately 180-200mg/dL Elevated: DM, Cushings syndrome, liver andpancreatic disease, Fanconis syndrome81 82. Ketonuria Normal: not present in urine Testing: presence of acetic acid through achemical reaction Causes: uncontrolled diabetes, pregnancy,carbohydrate-free diets, starvation 82 83. Nitrites Normal: Not present in urine Testing: bacteria that reduce urinary nitratesto nitrites -Positive test: can be gram negatives or grampositive organism (neg > pos) (>10,000/mL)Indicates significant number-Negative test: Cant R/O UTI because non-nitrate reducing organism can cause it 83 84. UTIs -NOTE: nitrite stick sensitive to air exposure:after one week of exposure about 1/3 of stripsgive false positive84 85. Leukocyte Esterase Testing: presence of neutrophils Sterile Pyuria: -Organisms: Chlamydia and Ureaplasmaurealyticum -Other causes: balantis (inflammed head ofpenis), urethritis, TB, bladder tumors, viralinfx, nephrolithiasis (kidney stones), foreignbody, exercise, glomerulonephritis,corticosteroid use 85 86. Bilirubin Normal Bilirubin: no detectable amounts -Unconjugated bili: not water soluble, doesntpass through glomerulus -Conjugated bili: water soluble, indicatespossible liver dysfunction or biliaryobstruction 86 87. Urobilinogen Normal Urobilinogen: only small amounts -Urobilinogen: end product of conjugated biliafter metabolized by intestine, small amountreabsorbed into portal circulation and filteredby glomerulus Increased urobilinogen: hemolysis,haptocellular disease Decreased urobilinogen: antibiotic use, bileduct obstruction87 88. 88 89. Fun Facts Cat urine, semen, and blood will glow underfluorescent light. So do most other bodily fluids. ... anything with phosphorus in it will glowunder a black light. 89 90. FUN URINARY TRACT DISCUSSION QUESTIONSCan you drink your own urine? Although urine is pretty clean, the exit tube (urethra) is not, so asit comes out, it gets contaminated like a garden hose with mudon the tip.Is it more sanitary to be spit on or peed on?If you are stranded on a desert island, should you drinkseawater or your own urine?Why do I have to go to the bathroom immediately after acup of coffee?Why do you have to pee when you hear water dripping?Does cranberry juice cure urinary tract infections?Yes, by deforming the disease-causing bacteria 90