4 URINARY SYSTEM.pdf

URINARY SYSTEM  DEVELOPMENT OF ANOMALIES FUNCTIONAL DISTURBANCES PATHOLOGY OF KIDNEY: a) GLOMERULONEPHRITIS, b) INTERSTITITAL NEPHRITIS, c) PYELONEPHRITIS, d) NEPHROSCALERIOSIS e) UROLITHIASIS PATHOLOGY OF URETER PATHOLOGY OF URINARY BLADDER: CYSTITIS PATHOLOGY OF URETRA: URET...

URINARY SYSTEM  DEVELOPMENT OF ANOMALIES FUNCTIONAL DISTURBANCES PATHOLOGY OF KIDNEY: a) GLOMERULONEPHRITIS, b) INTERSTITITAL NEPHRITIS, c) PYELONEPHRITIS, d) NEPHROSCALERIOSIS e) UROLITHIASIS PATHOLOGY OF URETER PATHOLOGY OF URINARY BLADDER: CYSTITIS PATHOLOGY OF URETRA: URETHRITIS  DEVELOPMENT OF ANOMALIES AGENESIS, APLASIA, HYPOPLASIA, HORSE SHOE SHAPED KIDNEYS AND CYST IN KIDNEY AGENESIS : it refers to congenital absence of one or both kidneys. Aplasia: absence of one or both kidneys. Absence of one kidney is observed in animals with compensatory hypertrophy of another kidney and which animals may survive well. Hypoplasia; the size of kidneys remains small as they do not grow properly due to defect in a single recessive genes. Horse shoe shaped kidneys; it is seen in all species of animals. This result from fusion of the kidneys at the posterior poles. -  Cyst in kidney: single and multiple cyst in pig and dog kidneys are reported with tinged yellow color. They arises from nephron due to - its distension. The presence of multiple cyst is also termed as congenital poly cystic kidney. TYPE-I POLYCYSTIC KIDNEY Ø Due to dilation and hyperplasia of collecting tubules Ø Spongiform kidneys Ø In such neonates cystic bile ducts are also present. TYPE-II POLYCYSTIC KIDNEY Ø Due to absence of collecting tubules and failure of nephron Ø Cysts are thick walled with dense connective tissue Ø Involve one or both kidneys TYPE-III POLYCYSTIC KIDNEY Ø Due to multiple abnormalities during development Ø Cysts from tubules or Bowmen’s capsule with part of glomeruli Ø Bilateral and causes considerable enlargement of kidney Ø Clear or blood mixed fluid containing cysts  FUNCTIONAL DISTURBANCES Proteinuria Ø Presence of protein particularly albumin in urine Ø As smooth, homogenous, pink staining precipitate also called as cast Ø Presence of albumin in urine is indicative of damage in glomeruli Ø It is also characterized by oedema due to protein deficiency Haematuria Ø Presence of blood in urine giving bright red colour Ø Due to damage or haemorrhages anywhere from glomeruli to urethra Ø Most important cause of haematuria ia bracken fern toxicity Ø Intact erythrocytes are present and settle down after some time leave clear urine as supernatant  FUNCTIONAL DISTURBANCES Haemoglobinuria Ø Presence of Hb in urine Ø Urine become brownish red in color Ø Caused by Leptospira spp., Babesia sp. or phosphorus deficiency in animals Ø Urine remains turbid and coloured on centrifugation\ Anuria Ø Absence of urine may be due to Ø Absence of urinary secretion due to glomerulonephritis Ø Inelastic renal capsule unable to exert sufficient pressure required for glomerular filtration leading to nephrosis Ø Due to hydronephrosis or calculi urine already secreted puts back pressure to prevent further secretion Ø Low blood pressure, Dehydration and Necrosis of tubular epithelium  FUNCTIONAL DISTURBANCES Polyuria vIncreased amount of urine leading to frequent urination vDue to diabetes insipidus, hormonal imbalance and polydipsia vIn this condition, waste products are successfully eliminated Oligouria; decreased amount of urine due to glomerulonephritis, obstruction, dehydration, low BP and tubular damage  FUNCTIONAL DISTURBANCES Uremia v Presence of waste products like uric acid, creatinine and urea in blood v Normally such waste products are removed by excretion through kidneys v Due to damage in kidneys or inflammation neoplasm, abscess and calculi v Urine remains in the system and caused uremia v Uremia is characterized by headache, vomiting, hyperirritability, convulsion, ulcers in oral cavity and stomach, normochromic and normocytic anemia, hemosiderosis and thrombocytopenia Glycosuria v Presence of glucose in urine v Also known as diabetes mellitus v It may occur due insulin deficiency v It may occur in dog as a result of hypoglyecemia v In sheep due to enterotoxaemia caused by Clostridium welchii type D  FUNCTIONAL DISTURBANCES Pyuria; presence of pus in urine ü Due to suppurative inflammation in urinary tract Ketonuria; presence of ketone bodies in urine ü Common in diabetes mellitus, acetonemia, pregnancy toxaemia and starvation Pollakiuria is increased frequency of urination (the amount may be normal). Dysuria is painful or difficult urination. Stranguria is the slow and painful discharge of urine due to spasm of the urethra or bladder. Myoglobinuria is the presence of myoglobin in the urine, due to muscle damage. Crystalluria is the presence of crystals in the urine.  Nephrosis Nephrosis is the degeneration and necrosis of tubular epithelium without producing inflammatory reaction. Includes acute tubular necrosis due to ischemia/toxic injury to kidney Characterized by necrosis and sloughing of tubular epithelial cells exhibited by uremia, oligouria and anuria. Etiology; hypotension, heavy metal, mycotoxin and antibiotic (Getamicin) Macroscopic features Swelling of kidney Capsular surface smooth, pale and translucent Microscopic features Vacuolation tn tubular epithelium Coagulative necrosis Sloughing of tubular epithelium Hydronephrosis is dilation of the renal pelvis due to obstruction of urine outflow and associated with increased pelvic pressure, dilation of the pelvis and atrophy of the renal parenchyma. v Hydronephrosis occurs in all domestic animal.  In Glomerulonephritis - Inflammation of glomeruli primarily characterized by pale and enlarged kidneys with potential haemorrhage, oedema of glomeruli, congestion and infiltration of inflammatory cells. Due to presence of mesangial proliferation, it is also called as mesangio proliferative glomerulonephritis. Etiology Sterptococci spp. infection Immune complexes reaction Environmental pollutants such as organochlorine pesticides Macroscopic features Enlarged kidney, oedema, pale kidneys Petechiae in kidneys Proteinuria, uremia, hypercholesterolemia and increased creatinine level in blood  Glomerulonephritis Microscopic features Oedema of glomeruli leading to increase in size Infiltration of neutrophils and macrophages Compression of blood capillaries and absence of erythrocytes Thrombosis and necrosis of glomerular capillaries Based on type of lesions, it can be divided into five sub types (type-I MPGN, type-II MPGN, type- III MPGN, Chronic glomerulonephritis and focal embolic glomerulonephritis)  Glomerulonephritis Type-I MPGN: Proliferation of mesangial cells. Deposition of immune complexes containing IgG, IgM, IgA and C3. Immune complexes penetrate vascular endothelium but not the basement membrane and are deposited in sub endothelial region. Proliferation and swelling of endothelial cells Immune complexes induce production of transforming growth factor which increases production of fibrino- lectin, collagen and proteoglycans leading to thickness of basement membrane, this is also known as “wire loop” lesion.  Glomerulonephritis Type-II MPGN: deposition of immune complexes in basement membrane Due to uncontrolled activation of complement Proliferation of endothelium and mesangial cells Demonstration of c3 complement, no immunoglobin Type-III MPGN: Sub epithelial deposition of immune complexes and disruption of basement membrane Swelling of epithelium and its proliferation forming epithelial crescent Demonstration of IgG in sub epithelial region Congestion and oedema in glomeruli Infiltration of neutrophils, macrophages and lymphocytes  Glomerulonephritis Chronic glomerulonephritis Proliferation of epithelial and endothelial cells Reduplication, thickening and disorganization of glomerular basement membrane Lumen of capillaries occluded. Entire glomerulus is replaced by hyaline connective tissue Focal embolic glomerulonephritis Focal zone of necrosis in glomeruli along with Infiltration of neutrophils Proliferation of epithelial cells and formation of crescent  Interstitial Nephritis Inflammation of kidney characterized by degeneration and necrosis of tubular epithelium, oedema and infiltration of inflammatory cells in interstitium Etiology Ochratoxin, Leptospira, toxin\ poisions (Pesticides), Viral infection, endogenous toxaemia (ketosis), immune complexes. Macroscopic features Enlargement of kidneys Necrosis, congestion and haemorrhagic kidney  Microscopic features edema, congestion and hemorrhage Necrosis and degeneration of tubular epithelium Infiltration of inflammatory cells like neutrophils, macrophage and lymphocytes in interstitum. Loss of tubules, foci of mononuclear cells, and fibrosis in chronic cases. Immune complexes are deposited in granular form causing degeneration of epithelial cells of tubules and mononuclear cell infiltration.  Pyelonephritis Inflammation of renal pelvis and renal parenchyma in which tubules - characterized by congestion, suppurative inflammation and fibrosis Etiology Corynebacterium renale, Staphylococcus aureus, E. coli, Actinomyces pyogenes and Pseudomonas aeruginosa Macroscopic features Congestion, hemorrhages and abscess formation in renal cortex, pelvis and ureter Pyuria ; pus mixed urine in bladder Enlargement of kidneys Macroscopic features Congestion and haemorrhages Suppurative inflammation of pelvis and kidney parenchyma Necrosis of collecting duct and purulent exudate in pelvis Infiltration of neutrophils, lymphocytes and plasma cells in intersttium  Nephrosclerosis Chronic fibrosis of kidney characterized by loss of glomeruli and tubules and extensive fibrosis Etiology; glomerulonephritis, interstitial nephritis and arterioscleresis Macroscopic features Hard, atrophied kidney, fibrosis nodules on kidneys, thickening of capsules and small white firm kidneys Microscopic features Ischemia tubular atrophy, loss of glomeruli and tubules Extensive fibrosis, deposition of hyaline mass Infiltration of mononuclear cells  Urolithiasis Formation of stone precipitates any where in the urinary passage including kidneys, ureter, urinary bladder and urethra Etiology Bacterial infections, Metabolic defect, Vitamins A deficiency, hyper-para thyrodism and mineral deficiency Macroscopic features Nephrosis, hydronephrosis, distention of ureter Distention of ureter and urinary bladder Hard enlarged kidneys Presence of calculi or stone in kidney, ureter, urinary bladder or urethra Various types of calculi which different in size, shape and composition Microscopic features Presence of crystals\ stone in lumen of tubules Degeneration and necrosis of tubular epithelium Proliferation of fibrosis tissue and haemorrhages  Classified of calculi Oxalate calculi ; Hard, Light yellow, covered with sharp spine found in urinary bladder Due to calcium oxalate and damage in urinary bladder leading to hemorrhage Uric acid calculi Composed of ammonium and sodium urates and uric acids Yellow in brown in color, formed in acidic urine and they are found in spherical and irregular shape. Phosphate calculi White or grey in color, Chalky in consistency, soft and friable. It can be crushed with mild pressure and Mostly multiple in the form of sand like granules It is composed of magnesium ammonium phosphate Occur as a result of bacterial infection Xanthine calculi Brownish red, concentrically laminated, fragile and irregular in shape. They rarely occur in animals  Ureteritis Inflammation of ureter characterized by enlargement, thickening of wall due to accumulation of urates or calculi, pyonephritis and pyelonephritis. Etiology; tuberculosis, calculi, hydronephrosis, pyelonephritis and pyonephritis. Macroscopic features; deposits of whitish/yellowish urates in ureter in poultry. Obstruction of ureter due to calculi leads its enlargement and formation of diverticulum. Microscopic features Thickening of the wall due to congestion and infiltration of inflammatory cells. Extensive fibrosis with infiltration of mononuclear cells in chronic cases.  Cystitis Inflammation of urinary bladder charaterized by congestion and fibrious, purulent or haemorrhagic exudate Etiology; urinary calculi, tuberculosis, blockage in urethra and bracken fern poisoning Macroscopic features Congestion, haemorrhage and enlargement of urinary bladder. Presence of small nodules on walls and thickening of wall Micrscopic features Congestion, haemorrhage and thickening of wall due to infiltration of neutrophils and macrophages. Granuloma in tuberculosis and fibrosis. Presence of neoplasm.  Urethritis Inflammation of urethra is known as urethritis which occurs as a result of catheter injury and calculi characterized by congestion, obstruction and hydronephrosis Etiology; calculi, catheter injury, Trichomonas foetus infection and Picorna virus infection Macroscopic features Transient inflammation, congestion and hemorrhage Stricture, diverticulum Obstruction due to calculi, presence of calculi Microscopic features Thickening due to inflammatory exudates