Disorders of Blood Pressure Regulation

Disorders of the Kidneys
Subject to many of the same types of disorders that affect other body structures
Developmental defects
Infections
Altered immune responses
Neoplasms
Fetal Anomalies
Most Common: Anomalies in shape and position
Less common are disorders involving:
A decrease in renal mass (e.g., agenesis, hypogenesis)
A change in renal structure (e.g., renal cysts)
Organ Development
Dysgenesis
Failure of an organ to develop normally
Agenesis
The complete failure of an organ to develop
Potter’s Syndrome
Characteristic facial features of newborns with renal agenesis
The eyes are widely separated and have epicanthic folds
The ears are low set
The nose is broad and flat
The chin is receding
Limb defects often are present
Causes of Neonatal Renal Failure with Potter Phenotype
Cystic renal dysplasia
Obstructive uropathy
Autosomal recessive polycystic disease
Unilateral agenesis (uncommon)
Cystic Disease of the Kidney
Definition
Fluid-filled sacs or segments of a dilated nephron
Causes
Tubular obstructions that increase intratubular pressure
Changes in the basement membrane of the renal tubules that predispose to cystic dilatation
Types of Cystic Disease of the Kidney
Simple and acquired renal cysts
Medullary Cystic Disease
Polycystic Kidney Disease
Autosomal Recessive Polycystic Kidney Disease
Autosomal Dominant Polycystic Kidney Disease

Causes of Urinary Tract Obstruction
Developmental defects
Calculi (stones)
Pregnancy
Benign prostatic hyperplasia
Scar tissue resulting from infection and inflammation
Tumors
Neurologic disorders such as spinal cord injury
Damaging Effects of Urinary Obstruction
Stasis of urine
Predisposes to infection and stone formation
Development of backpressure
Interferes with renal blood flow and destroys kidney tissue

Manifestations of Urinary Obstruction
Depend on:
The site of obstruction
The cause
The rapidity with which the condition developed
Common Symptoms:
Pain
Signs and symptoms of UTI
Manifestations of renal dysfunction
Kidney Stones
Definition
Crystalline structures that form from components of the urine
Requirements for formation
A nidus to form
A urinary environment that supports continued crystallization of stone components
Factors Influencing the Formation of Kidney Stones
The concentration of stone components in the urine
The ability of stone components to complex and form stones
The presence of substances that inhibit stone formation

Types of Kidney Stones
Calcium stones
Oxalate or phosphate
Magnesium ammonium phosphate stones
Uric acid stones
Cystine stones
Types of Urinary Tract Infections
Asymptomatic bacteriuria
Symptomatic infections
Lower UTIs
Cystitis
Upper UTIs
Pyelonephritis
Causes of UTIs
Most uncomplicated UTIs caused by Escherichia coli
Other uropathic pathogens include:
Staphylococcus saprophyticus in uncomplicated UTIs
Both non-E coli gram-negative rods (Proteus mirabilis, Klebsiella pneumoniae, Enterobactero, Pseudomonas, and Serratio)
Gram-positive cocci (Staphylococcus aureus, Group B Streptococcus) in complicated UTIs
Most caused by bacteria that enter through the urethra
Causes of UTIs Associated with Stasis of Urine Flow
Anatomic obstructions
Urinary tract stones
Prostatic hyperplasia
Pregnancy
Malformations of the ureterovesical junction
Causes of UTIs Associated with Stasis of Urine Flow (cont.)
Functional obstructions
Neurogenic bladder
Infrequent voiding
Detrusor (bladder) muscle instability
Constipation


Characteristics of Acute Episode of Cystitis
Frequency of urination (as often as every 20 minutes)
Lower abdominal or back discomfort
Burning and pain on urination (dysuria)
Cloudy and foul smelling urine on occasion
Categories of Urinary Tract Infections
Acute
Recurrent
Chronic
Manifestations of Asymptomatic UTIs During Pregnancy
Persistent bacteriuria
Acute and chronic pyelonephritis
Toxemia of pregnancy
Premature delivery
Characteristics of Glomerulonephritis
Hematuria with red cell casts
A diminished glomerular filtration rate (GFR)
Azotemia (presence of nitrogenous wastes in the blood)
Oliguria
Hypertension
Causes of Glomerulonephritis
Diseases that provoke a proliferative inflammatory response of the endothelial, mesangial, or epithelial cells of the glomeruli
The inflammatory process:
Damages the capillary wall
Permits red blood cells to escape into the urine
Produces hemodynamic changes that decrease the GFR


Types of Glomerular Diseases
Acute proliferative glomerulonephritis
Rapidly progressive glomerulonephritis
Nephrotic syndrome
membranous glomerulonephritis
Minimal change disease (lipoid nephrosis)
Focal segmental glomerulosclerosis
IgA nephropathy
Chronic glomerulonephritis

Tubulointerstitial Disorders
Acute tubular necrosis
Renal tubular acidosis
Pyelonephritis
The effects of drugs and toxins

Major Groups of Renal Neoplasms
Embryonic kidney tumors occurring during childhood
Wilms’ tumor
Adult kidney cancers