1、1,Alterations of Renal and Urinary Tract Function in Children,Chapter 37,2,Development of the Urinary Renal System,Pronephros Mesonephros Metanephros Ureteric bud Metanephrogenic blastema Urine formation and excretion begin by the third month of gestation,3,Development of the Urinary Renal System,4,
2、Fluid and Electrolyte Balance,Blood flow to the kidney in a newborn is primarily to the medullary nephrons Due to the short loops of Henle in the medullary nephrons, an infant produces more dilute urine Infants are in a high anabolic state, so their urea excretion is low Urea is required to establis
3、h the concentration gradient in the medulla,5,Fluid and Electrolyte Balance,Infants have a narrow chemical safety margin due to high hydrogen ion concentration, low osmotic pressure, and limited ability to regulate their internal environment Diarrhea, infection, fasting, and poor feeding can rapidly
4、 lead to severe acidosis and fluid imbalance,6,Structural Abnormalities,Ectopic kidneys Horseshoe kidneys Hypospadias Chordee Epispadias Exstrophy of the bladder,7,Structural Abnormalities,Ureteropelvic junction obstruction Bladder outlet obstruction Hypoplastic or dysplastic kidneys Renal agenesis
5、Polycystic kidney disease,8,Glomerulonephritis,Acute poststreptococcal glomerulonephritis (PSGN) PSGN occurs after a throat or skin infection with certain strains of group A -hemolytic streptococci The patient experiences a sudden onset of hematuria, edema, hypertension, and renal insufficiency Anti
6、gen-antibody complexes and complement are deposited in the glomerulus The immune complexes initiate inflammation and glomerular injury,9,Glomerulonephritis,Immunoglobulin A nephropathy IgA nephropathy is characterized by the deposition of mostly IgA but some IgM antibodies and complement in the mesa
7、ngium of the glomerular capillaries. Henoch-Schnlein purpura nephritis Also referred to as anaphylactoid purpura IgA nephropathy that causes inflammation and damage to the glomerular blood vessels,10,Hemolytic-Uremic Syndrome (HUS),HUS is the most common cause of acute renal failure in children Ther
8、e is an association of HUS with bacterial and viral agents Escherichia coli O157:H7 The bacterial toxin from E. coli damages red cells and endothelial cells The endothelial lining of the glomerulus becomes swollen and occluded with fibrin clots,11,Hemolytic-Uremic Syndrome (HUS),HUS causes a decreas
9、ed glomerular filtration rate with hematuria and proteinuria The swollen vessels damage red cells as they pass The damaged red cells are removed from the circulation by the spleen, causing acute hemolytic anemia The microcirculation develops numerous thrombi,12,Nephrotic Syndrome,Nephrotic syndrome
10、describes a group of symptoms characterized by proteinuria, hypoproteinemia, hyperlipidemia, and edema Minimal change nephropathy (MCN) Focal segmental glomerulosclerosis (FSGS) Mesangial proliferation Nephrotic syndrome can develop as part of numerous renal diseases,13,Urinary Tract Infections (UTI
11、),UTIs are common 7- to 13-year-old girls E. coli, the most common pathogen, ascends the urethra in cystitis or the ureter in pyelonephritis Cystitis Acute pyelonephritis,14,Vesicoureteral Reflux (VUR),Retrograde flow of urine from the bladder into the ureters Reflux encourages infected urine from t
12、he bladder to be swept up into the kidneys Leads to frequent pyelonephritis Caused by a congenital abnormality or ectopic insertion of the ureter into the bladder Diagnosed by a voiding cystourethrogram (VCUG) and an intravenous pyelogram (IVP),15,Vesicoureteral Reflux (VUR),16,Vesicoureteral Reflux
13、 (VUR),17,Wilms Tumor,Wilms tumor is an embryonal tumor of the kidney Wilms tumor arises from the proliferation of abnormal renal stem cells (metanephric blastema) Three cellular components: Stromal, epithelial, and blastemic Inherited and sporadic forms,18,Enuresis,Involuntary passage of urine by a
14、 child who is beyond the age when voluntary bladder control should have been acquired 4 to 5 years old Primary enuresis The child has never been continent Secondary enuresis Diurnal, nocturnal, or both,19,Enuresis,Theories Organic causes Maturational lag Genetic factors Sleep patterns Psychosocial theories,
