Lecture 16 CH19 Renal System and Homeostasis PDF

The Urinary System and Fluid Homeostasis Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com. Learning Objectives Describe the role of the kidneys in maintaining water and electrolyte balance in the body. 2. Describe the role of the kidneys in the re...

The Urinary System and Fluid Homeostasis Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com. Learning Objectives Describe the role of the kidneys in maintaining water and electrolyte balance in the body. 2. Describe the role of the kidneys in the regulation of water volume, osmolality and blood pH. 3. Describe the normal structures of the kidneys and their functions with special emphasis on the nephron. 4. Describe chronic kidney disease and its most common causes. 5. Explain the pathogenesis of glomerulonephritis, nephrosis, and nephrosclerosis. Describe the clinical manifestations of each of these disorders. 6. Describe acute tubular injury and tubulointerstitial nephritis. 7. Describe the clinical manifestations and complications of urinary tract infections. 8. Explain the mechanism for formation of urinary tract calculi. Describe the complications of stone formation. Explain the manifestations of urinary tract obstruction. Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com 1. Learning Objectives 9. Differentiate the major forms of cystic disease of the kidney and their prognoses Name the more common kinds of tumors affecting the urinary tract. 11. Describe the causes, symptoms, and treatment of renal failure. 12. Describe the principles and techniques of hemodialysis and renal transplantation. 13. Describe the techniques used to evaluate kidney disease. Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com 10. Body Water Content 50-60% of body weight is water (Female-Male) Electrolytes – dissolved mineral salts that dissociate in solution (anions/cations) ▪ Principal extracellular ions are sodium, chloride and bicarbonate ▪ Principal intracellular ions are potassium, magnesium and phosphate ▪ Cell wall is freely permeable to water, not ions (controlled by active transport) ▪ Overall electrical charge is neutral in both intracellular and extracellular fluid compartments Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com 2/3 of water is contained in cells, 1/3 extracellular which include plasma (circulatory system) and interstitial fluid in tissues Control of Overall Extracellular Water Volume and Osmolality 1. Osmoregulation is controlled by water intake and excretion (sweat, urine) ie – water loss increases sodium concentration. 2. Volume regulation is primarily controlled by sodium retention and excretion These 2 systems are regulated independently and have different sensors, effector mechanisms and effects – both involve the kidneys Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Osmolality is essentially equivalent to plasma sodium concentration – Controlled by 2 independent regulatory processes: Disturbances of H2O Balance Disturbances of H2O balance Overhydration: Less common ▪ Excessive fluid intake when renal function is impaired: Renal disease; excessive intake of fluids; excessive administration of IV fluids Hypovolemia is a decrease in plasma volume and loss of blood pressure Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Dehydration: Most common ▪ Inadequate intake: Comatose or debilitated patients ▪ Excess H2O loss: Diarrhea or vomiting Regulation of Plasma pH Depends on regulation of bicarbonate and dissolved carbon dioxide (carbonic acid) Variations of plasm pH above/ below can have serious impacts on health (alkalosis/acidosis) ▪ Kidney plays 2 roles in regulating blood pH (slow) 1. Kidneys reabsorb bicarbonate and manufacture bicarbonate 2. Acidic metabolic products are excreted by kidney. ▪ Amount of dissolved carbon dioxide is controlled by respiratory rate (rapid) Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Plasma pH maintained between 7.37 and 7.42 Disturbances in Acid–Base Balance Alkalosis ▪ Blood pH shifts to basic side ▪ From a decrease of H2CO3 (carbonic acid) or from an increased amount of bicarbonate Metabolic: Disturbance lies in bicarbonate member of the buffer pair Respiratory: Disturbance lies in carbonic acid member of the buffer pair Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Acidosis ▪ Blood pH shifts to acidic side ▪ From an excess of H2CO3 (carbonic acid) or from a reduced amount of bicarbonate Classification of Acid–Base Disturbances ▪ Amount of acid generated exceeds body’s buffering capacity ▪ Excess acid is neutralized by bicarbonate ▪ Bicarbonate in plasma falls from being consumed in neutralizing excess acid ▪ Uremia, ketosis, lactic acidosis Compensation: By hyperventilation to lower PCO2 and increased bicarbonate production in kidneys Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Metabolic acidosis: Increased endogenous acid generated Classification of Acid–Base Disturbances ▪ Inefficient exhalation of CO2 by lungs ▪ Leads to retention of CO2 and rise in H2CO3 ▪ Compensation: Increased bicarbonate production in kidneys Metabolic alkalosis: Increased plasma bicarbonate conc ▪ From loss of gastric juice, chloride depletion, excess corticosteroids, excess antacids ▪ With coexisting potassium deficiency ▪ Compensation: Inefficient, requires simultaneous correction of potassium deficiency Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Respiratory acidosis: Increased H2CO3 concentration Classification of Acid–Base Disturbances ▪ Hyperventilation lowers PCO2, and H2CO3 level falls ▪ Relative excess of bicarbonate ▪ Compensation: Excretion of bicarbonate by kidneys Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Respiratory alkalosis: Reduced H2CO3 concentration Respiratory Control of pH ▪Decreased respiration causes elevation of alveolar PCO2, raising plasma carbon dioxide Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪Increased respiration lowers carbon dioxide concentration making blood more alkaline Respiratory Control of pH Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com FIGURE 19-3 A summary of metabolic and respiratory control of plasma pH. Common Acid–Base Disturbances Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Kidneys Divided into outer cortex and inner medulla (renal pyramids and columns) Excretory organs, functions along with lungs in excreting waste products of food metabolism and homeostasis Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Paired, bean-shaped organs below diaphragm adjacent to vertebral column Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Kidneys Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Three basic functions 1.Excrete waste products of food metabolism ▪ End products of carbohydrate and fat metabolism ▪ Urea - end product of protein metabolism ▪ Uric Acid – nucleic acid metabolism 2. Regulate mineral, electrolyte, acids and H2O balance ▪ Excretes excess minerals, electrolytes and H2O ingested and conserves them as required ▪ Body’s internal environment is determined not by what a person ingests, but by what the kidneys retain 3. Produce erythropoietin, thrombopoietin and renin: Specialized cells in the kidneys ▪ Erythropoietin: Regulates red blood cell production in marrow ▪ Renin: Helps regulate blood pressure Urinary System Bladder: Stores urine ▪ Discharges urine into urethra during voiding ▪ Anatomic configuration of bladder and ureters normally prevents reflux of urine into ureters Urethra: Conveys urine from the bladder for excretion Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Excretory duct system ▪ Ureter: Conveys urine into bladder by peristalsis ▪ Renal pelvis: Expanded upper portion of ureter ▪ Major calyces: Subdivisions of renal pelvis ▪ Minor calyces: Subdivisions of major calyces into which renal papillae discharge Nephrons : basic structural and functional unit of the kidney, about 1-1.5 million nephrons in each kidney Both passive and active transport processes are involved Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Nephron: uses filtration (glomerulus), absorption and Reabsorption, secretion and excretion (tubules/collecting duct) to process filtrate from the blood for excretion in the urine The Glomerulus Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Glomerulus ▪ Tuft of capillaries supplied by an afferent glomerular arteriole that recombines into an efferent glomerular arteriole ▪ Material is filtered by a three-layered glomerular filter ▪ Inner: Fenestrated capillary endothelium ▪ Middle: Basement membrane ▪ Outer: Capillary endothelial cells (with foot processes and filtration slits) ▪ Mesangial cells: Contractile phagocytic cells that hold the capillary tuft together; regulate caliber of capillaries affecting filtration rate Glomerular Filtration Control of rate of glomerular filtration (GFR) critical ▪ GFR is controlled by the kidney through changes in resistance in blood flow in glomerular arteriole (afferent arteriolar tone) ▪ Increased arterial pressure increases resistance (tone) of afferent arteriole of glomerulus-regulating GFR ▪ Increased pressure in the afferent arteriole is sensed by the macula densa (in the loop of Henle), which also increases tone of the afferent arteriole to regulate GFR. ▪ Filtration failure will result in buildup of metabolic toxins and nitrogenous wastes (urea) in the blood (azotemia) which can lead to multi organ failure and death Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ Factors that control GFR are porosity and length of glomerular capillary, differences in fluid pressure and oncotic pressure (inside/outside capillary) Renal Tubules of Nephron ▪ Similar to capillary bed in periphery ▪ Proximal end: Bowman capsule ▪ Distal end: Empties into collecting tubules Requirements for normal renal function ▪ Free flow of blood through the glomerular capillaries ▪ Normally functioning glomerular filter that restricts passage of blood cells and protein ▪ Normal outflow of urine https://quizlet.com/246107577/nephron-filtration-diagram/ Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Renal tubule: Reabsorbs most of filtrate; secretes unwanted components into tubular fluid; regulates H2O balance Functions of the Nephron Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Control of Plasma Osmolality 200L of fluid filtered/day – normal urine output is 1-2 L/day (most water (99%) and sodium are reabsorbed) ▪ Hyponatremia – results in cell swelling, Hypernatremia – cell shrinkage (osmosis) ▪ Either can result in severe impacts on cell/organ functions ▪ High plasma osmolality is sensed in hypothalamus; results in thirst and secretion of antidiuretic hormone (ADH) from posterior pituitary ▪ Water intake is increased, urine output is decreased (by ADH), and sodium concentration drops Diabetes insipidus: cause by lack of secretion of ADH or failure of kidney response to ADH – resulting in large amounts of urine production (20L/day) and dehydration. Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ Plasma osmolality is mainly controlled by sodium concentration and depends on water uptake and loss (diuresis [urination]) Kidney Control of Blood Pressure Hypoperfusion of the kidney (low blood pressure or volume –is prolonged causes renal injury) is sensed in by the juxtaglomerular cells in the walls of the afferent glomerular arteriole ▪ Renin: Released in response to decreased blood volume, low blood pressure– converts angiotensinogen to Angiotensin I ▪ Angiotensin I → angiotensin II by angiotensin-converting enzyme (ACE) as blood flows through the lungs ▪ Angiotensin II: ▪ Powerful vasoconstrictor: Raises blood pressure by causing peripheral arterioles to constrict ▪ Stimulates aldosterone secretion from adrenal cortex: Increases reabsorption of NaCl and H2O by kidneys ▪ Net effect: Higher blood pressure, increased fluid in vascular system System is self-regulating Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com results in renin release into the blood and activation of the RAAS (renin–angiotensin–aldosterone system) regulating systemic blood pressure Role of Kidneys in Regulation of Blood Pressure and Blood Volume Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com FIGURE 19-8 The role of the kidneys in the regulation of blood pressure and blood volume. Diuretics Increase water and sodium excretion to reduce blood volume Tx: hypertension, edema, CHF 3 main types: ▪ Loop diuretics (furosemide) – block sodium reabsorption in ascending loop of Henle (major site of sodium reabsorption) ▪ Thaizide diuretics (hydrocholorthiazide) ▪ Potassium sparing diuretics (spirolactone) Also: osmotic diuretics (mannitol) and Carbonic anhydrase inhibitors (acetazolamide) McMaster physiology review: http://www.pathophys.org/diuretics/ Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Reduce sodium/water reabsorption Diagnostic Evaluation of Kidney and Urinary Tract Disease ▪ Urine culture - bacteria ▪ Blood chemistry tests ▪ Kidney function tests ▪ BUN (blood urea nitrogen test) ▪ Glomerular filtration rate (GFR) ▪ Creatinine clearance test ▪ X-ray studies (with/without contrast) ▪ Ultrasound examination ▪ Cystoscopy Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ Urinalysis (pH, conc, glucose, protein, bile, blood, casts) Developmental Abnormalities of the Urinary System Normal development Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ Kidneys arise from mesoderm, develop in pelvis, ascend to final position ▪ Kidneys begin development in the pelvis and then occupy a higher location as they develop – ascending to final positions in lower lumbar region ▪ Bladder derived from lower end of intestinal tract ▪ Excretory ducts (ureters, calyces, pelvis) develop from ureteric buds that extend from bladder into the developing kidneys Congenital Abnormalities Duplications of urinary tract (C) ▪ Complete duplication: Formation of extra ureter and renal pelvis ▪ Incomplete duplication: Only upper part of excretory system is duplicated Failure of kidney ascent (D) Malposition: (E/F) One or both kidneys, associated with fusion of kidneys; horseshoe kidney; fusion of upper pole – often of little clinical significance, may have some abnormalities in drainage of urine Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Renal agenesis (B): Failure of one or both kidneys to develop ▪ Bilateral: Rare, associated with other congenital anomalies, incompatible with life ▪ Unilateral: Common, asymptomatic; other kidney enlarges to compensate (relatively common 1:1000) Renal Failure Failure of renal function can be: acute (develops rapidly and tends to resolve) or chronic (develops slowly with permanent damage) ▪ Hypertension and atherosclerosis of renal artery causing ischemic nephropathy ▪ high sugar levels in blood from diabetes clog and damage tiny vessels in kidney (thickening/scarring) Post-renal: often obstructive – bladder stones, prostatic diseases, cancer Damage kidney when urine blockage causes pressure buildup in kidney Renal Failure is the end stage of many kidney diseases and is associated with: ▪ Retention of urea in the blood (Uremia) ▪ Metabolic acidosis – from inability to remove waste products Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Pre-renal: Acute kidney Injury (AKI) Causes: ▪ Trauma/ Surgery complications (decreased renal blood flow) ▪ low BP (shock) ▪ Urinary tract blockage – stones, cancer ▪ Medications - NSAIDS ▪ Diseases that increase load on kidneys (toxins /muscle deterioration/hemolytic diseases) Tx: treat underlying cause – if done soon enough, should prevent permanent damage to kidney – dialysis may be required until cause is treated Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Progress is rapid – characterized by decreased urine output (50-70%), fluid and electrolyte imbalances Chronic kidney Injury (CKI) ▪ Renal function remains regular until the number of functioning nephrons declines to 30% of normal. ▪ Abnormal renal function for > 3 months is classified as chronic renal disease ▪ Chronic renal disease goes through stages (1-5: normal, mild, moderate, severe, end stage) – classified by declining GFR ▪ ESRD (stage 5) resulting in uremia is associated with complete kidney failure and requires treatment such as dialysis or renal transplant to sustain life Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ Remaining nephrons “work harder” to compensate, resulting in progression of CKI Pathogenesis and progression of CKI Hypertensive Nephrosclerosis Complication of severe, uncontrolled hypertension Common cause of chronic renal disease Glomeruli and tubules undergo secondary degenerative changes, causing narrowing of lumen and reduction in blood flow. Increased Glomerular pressure also causes damage to filtration barrier ▪ Reduced glomerular filtration ▪ Kidneys undergo scarring and shrinkage (from reduced blood supply) ▪ Progress to ESRD Scarring of kidney from nephrosclerosis Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Renal arterioles in nephrons undergo thickening from carrying blood at a much higher pressure than normal (nephrosclerosis) Diabetic Nephropathy Nodular and diffuse thickening of glomerular basement membranes (glomerulosclerosis), usually with coexisting nephrosclerosis Once initiated, can’t be reversed but progress can be slowed dependent on glycemic control (along with Hypertension if present) Manifestations ▪ Progressive impairment of renal function ▪ As filtration membrane of glomerulus is damaged – protein is lost in urine (proteinuria) ▪ Protein loss may lead to nephrotic syndrome No specific treatment can arrest progression of disease ▪ Progressive impairment of renal function may lead to ESRD Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Complication of long-standing diabetes (hyperglycemia) ▪ Half of ESRD patients have type II diabetes (often complicated with coincident hypertension) End Stage Renal Disease (Uremia) Progressive loss of renal function eventually leads to: ▪ Fluid, electrolyte, acid–base regulation failure ▪ Metabolic acidosis ▪ Lack of erythropoietin leads to anemia ▪ Level of urea (non toxic) in blood (blood urea nitrogen BUN) correlates with waste accumulation in the blood and progression of clinical condition. ▪ Measurement of severity of renal failure ▪ Clinical manifestations tend to occur once 80% of renal function is lost Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ Retention of excessive by-products of protein metabolism (urea) in the blood (uremia) End Stage Renal Disease (Uremia) Clinical manifestations Treatment ▪ Hemodialysis, Peritoneal Dialysis ▪ Transplantation Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ Weakness, loss of appetite, nausea, vomiting ▪ Anemia (failure of Epo production – endocrine function) ▪ Toxic manifestations from retained waste products (weakness, lethargy, neuropathy (delirium), cardiovascular disease ▪ Retention of salt and water causes edema ▪ Blood volume increased – Hypertension ▪ Coma, convulsions, death Dialysis Substitutes for the functions of the kidneys by removing waste products from patient’s blood Waste products in patient’s blood diffuse across a semipermeable membrane into a solution (dialysate) into the other side of the membrane Two types ▪ Extracorporeal dialysis (more common): Patient’s circulation connected to an “artificial kidney” machine: blood exits the body, cleaned and then returned (3 x/week, 3-4 hours) - Commonly at outpatient clinic, can be preformed at home with assistance of trained family member. ▪ Peritoneal dialysis (less common): Patient’s own peritoneum is used as the dialyzing membrane Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Can be used indefinitely or during period while waiting for kidney transplant Dialysis Connecting artery to vein make blood vessel wider/stronger to handle needles/ increased blood flow Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Regular hemodialysis, fistula can provide ease of vascular access: arteriovenous fistula, AV graft, catheter https://www.niddk.nih.gov/health-information/kidney-disease/kidney-failure/hemodialysis Renal Transplantation Attempted when kidneys fail Acceptance of transplant organ depends on similarity of human leukocyte antigens (HLA) between donor and recipient ▪ The patient’s immunologic defenses will respond to any foreign antigens and attempt to destroy (reject) foreign kidney ▪ Immunosuppressive drugs (indefinitely) Prognosis ▪ More than 90% of transplanted kidneys last for 5 years with good HLA match ▪ 10y survival rate is 50% ▪ More susceptible to infections (immunosuppression) ▪ Most rejections in the first few months Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Best if from a close relative donor (living donor -sibling match) can also be obtained from unrelated –matched deceased donor Glomerulonephritis Inflammation of the glomeruli caused by immune reaction within glomerulus - Autoimmunity In some cases, glomerulonephritis may rapidly progress to ESRD without immunosuppressive therapy Usually follows a beta-streptococcal infection ▪ Circulating antigen and antibody complexes are filtered by glomeruli and cause inflammation ▪ Injury is caused by Leukocyte infiltration and release lysosomal enzymes that cause injury to the glomeruli ▪ Causes glomerular necrosis ▪ Decreased urine output, waste accumulation in blood. ▪ Occurs in Lupus, immune complexes trapped in glomeruli ▪ Occurs in IgA nephropathy Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com formation of antigen:Ab complexes or autoantibodies within glomerular capillaries, or deposited from circulation Glomerulonephritis – Autoimmune disorders Type I membranoproliferative glomerulonephritis can follow other bacterial/ viral infections – immune complexes are found in mesangial cells (support glomerular structure – keep filtration membranes clear, remove debris) – chronic, slow progression leading to renal failure Anti GBM glomerulonephritis – autoantibodies against basement membrane –progresses rapidly ANCA (anti neutrophil cytoplasmic antibody) glomerulonephritis – characterized by destruction/inflammation of small blood vessels. ▪ ANCA antibodies react with cytoplasmic components of neutrophils ▪ provokes inflammatory reaction from neutrophils, destroys glomerular capillary endothelial cells (severe disease, progresses rapidly) – also affects small vessels in stomach, intestine and lungs. Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Poststreptococcal Glomerulonephritis –occurs after infection resolved (strep throat) in affected individuals, antistreptococcal antibodies form immune complexes with strep antigens – small complexes pass, but larger complexes become trapped in filtration membrane causing inflammation usually acute and self limiting Renal Cysts Solitary cysts common; not associated with impairment of renal function No specific treatment (dialysis/transplant) Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Multiple cysts ▪ Congenital polycystic kidney disease ▪ Autosomal (adult) dominant polycystic kidney disease (PKD1/2) ▪ Most common cause of multiple cysts ▪ Cysts enlarge, compress and slowly destroy renal tissue (completely) ▪ Onset of renal failure by late middle age (40s) ▪ Once progression is advanced – kidney failure with hematuria from bleeding into cysts ▪ Suspected by physical examination that reveals greatly enlarged kidneys – confirmed by ultrasound/CT Renal Tumors Arise from a number of regions: Transitional cell tumor: Arise from transitional epithelium lining urinary tract ▪ Most arise from bladder epithelium, common first manifestation is hematuria ▪ Low-grade malignancy; good prognosis Nephroblastoma Arise from remnant embryonic tissue :Uncommon; highly malignant, metastasizes widely; affects infants and children Diagnosis ▪ Urinalysis, culture, clearance tests ▪ Blood chemistry tests ▪ X-ray, ultrasound, cystoscopy, biopsy Treatment: Nephrectomy, radiotherapy, chemotherapy Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Cortical tumors: Arise from epithelium of renal tubules ▪ Adenomas: Usually small and asymptomatic, carcinomas more common ▪ Hematuria often first manifestation ▪ tumor invades renal vein and metastasizes into bloodstream Renal Disease - Nephrotic Syndrome Clinical manifestations ▪ Marked leg edema ▪ Ascites (fluid in abdominal cavity) ▪ Hydrothorax (fluid in pleural cavity) Prognosis ▪ In children: Minimal lasting effects, complete recovery with corticosteroids ▪ In adults: progressive renal disease Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Glomerular renal disease associated with Marked loss of protein in the urine (nephrosis) ▪ Caused by glomerular disease that results in destruction and failure of filtration barrier in glomerulus ▪ Protein is lost in urine in such excess that protein level in blood falls ▪ Causes edema due to low plasma osmotic pressure Renal disease - Acute Renal Tubular Injury Pathogenesis Clinical manifestation ▪ Acute renal failure: Oliguria, anuria ▪ Tubular function gradually recovers as damaged epithelium is regenerated ▪ Treated by dialysis until function returns (weeks to months) Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ Impaired renal blood flow ▪ Tubular necrosis caused by infection, toxic drugs or chemicals ▪ Any condition associated with shock and marked drop in BP – decreased blood supply and damage to tubules Diseases of Urinary Tract (UTI) Very common; may be acute or chronic Conditions protective against infection ▪ Free urine flow ▪ Large urine volume ▪ Complete bladder emptying ▪ Acid urine: Most bacteria grow poorly in an acidic environment Predisposing factors ▪ Any condition that impairs free drainage of urine ▪ Stasis of urine favors bacterial growth ▪ Injury to mucosa by kidney stone disrupts protective epithelium, allowing bacteria to invade deeper tissue ▪ Introduction of catheter or instruments into bladder may carry bacteria Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Most infections are caused by gram-negative intestinal bacteria that contaminate perianal and genital areas and ascend urethra Cystitis Clinical manifestations ▪ Burning pain on urination ▪ Desire to urinate frequently ▪ Urine contains many bacteria and leukocytes ▪ Responds well to antibiotics ▪ May spread upward into renal pelvis and kidneys Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Affects only the bladder ▪ More common in women than men; urethra in female is shorter; in young, sexually active women - sexual intercourse promotes transfer of bacteria from urethra to bladder ▪ Common in older men because enlarged prostate interferes with complete bladder emptying Pyelonephritis Involvement of upper urinary tract Clinical manifestations: Similar with an acute infection ▪ Localized pain and tenderness over affected kidney ▪ Responds well to antibiotics ▪ Cystitis and pyelonephritis are frequently associated ▪ Some cases become chronic and lead to kidney failure Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ Ascending infection from the bladder (ascending pyelonephritis) ▪ Carried to the kidneys from the bloodstream (hematogenous pyelonephritis) Vesicoureteral Reflux (VUR) https://www.kidney.org/atoz/content/vesicoureteral-reflux-vur-infants-children Urine normally prevented from flowing back into ureters from bladder Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Failure of valve allows bladder urine to reflux into ureter and into kidneys in severe cases – valve defect/ neurogenic/ urethra blockage ▪ Often self resolves without treatment in infants as they develop/mature ▪ Can cause kidney scarring/damage in severe cases ▪ Predisposes to urinary tract infection ▪ Bladder problems (incontinence, bedwetting) ▪ Predisposes to kidney infection https://www.niddk.nih.gov/health-information/urologic-diseases/hydronephrosis-newborns/vesicoureteral-reflux Urinary Calculi Stones may form anywhere in the kidney/urinary tract High concentration – saturates and forms precipitates to form calculi (stones) that start small, but once nucleated may grow larger, if they remain in urinary tract Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Predisposing factors ▪ Low fluid intake ▪ High concentration of salts in urine saturates urine, causing salts to precipitate and form calculi (from uric acid, calcium salts) ▪ Increased Uric acid excretion from gout ▪ Increased Calcium salts in urine from hyperparathyroidism ▪ Urinary tract infections reduce solubility of salts in urine; clusters of bacteria are sites where urinary salts may crystallize to form stone ▪ Urinary tract obstruction causes urine stagnation, promotes stasis and infection, further increasing stone formation Urinary Calculi Small stones may pass through ureters, causing renal colic Stones can become impacted in the ureter and need to be removed Manifestations ▪ Renal colic associated with passage of small stone ▪ If damage caused to ureter as they pass - hematuria ▪ Obstruction of urinary tract causes hydronephrosis or hydroureter proximal to obstruction Treatment ▪ Cystoscopy: remove stones lodged in distal ureter ▪ Xray/shock wave lithotripsy: Stones lodged in proximal ureter are broken into fragments that are readily excreted Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Staghorn calculus: Urinary stones that increase in size to form large branching structures that adapt to the contour of the pelvis and calyces Urinary Obstruction Manifestations ▪ Hydroureter: Dilatation of ureter ▪ Hydronephrosis: Dilatation of pelvis and calyces in kidney(s) Causes ▪ Bilateral: Obstruction of bladder neck by enlarged prostate or urethral stricture ▪ Unilateral: Ureteral stricture, calculus, tumor Complications: stone formation, infections, Kidney damage/failure ▪ Diagnosis and treatment: Pyelogram (X-ray with IV contrast – collects in urine, CT scan) Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Blockage of urine outflow leads to progressive dilatation of urinary tract proximal to obstruction, eventually causes compression, destruction of kidney parenchyma and atrophy Urinary Obstruction Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com Renal Cancer Kidney cancer – typically form in the tubules (renal cell carcinoma) most are found before they can spread, easily treated when caught early Bladder/ureteral cancer (common) ▪ Urothelial carcinoma (most common) - cells that line the bladder/ureters ▪ squamous and adenocarcinoma (rare) – also responds well to treatment Symptoms: Hematuria, painful/frequent urination, lower back pain (1 sided) Urethral cancer (rare – 1% of all urogenital cancers) Symptoms: Hematuria, painful urination, unable to empty bladder – frequent urge to urinate Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com ▪ Hematuria, fatigue, weight loss, anemia The Urinary System and Fluid Homeostasis Copyright © 2021 by Jones & Bartlett Learning, LLC an Ascend Learning Company. www.jblearning.com.