Answer to Question 1
Renal agenesis: failure of one or both kidneys to develop; bilateral agenesis is uncommon
Duplications of the urinary tract: formation of extra ureters and renal pelves secondary to the abnormal prenatal development of ureteric buds; may unilateral or bilateral; when there is an extra renal pelvis present, it is known as a complete duplication. Partial duplication is union of both ureters to form a single ureter that enters the bladder.
Abnormalities of position and fusion: kidneys either remain in the pelvis or ascend part way; most common fusion is the union of the lower poles of the two kidneys to form a U-shaped mass of renal tissue or a horseshoe-shaped kidney
Answer to Question 2
Immune complex glomerulonephritis: antigen-antibody complexes are filtered from the blood and accumulate within the walls of the glomerular capillaries where they incite an acute inflammation. Injury to the tissues results from the action of complements and leukocytes; these block the glomeruli, resulting in less blood filtered, less urine output with retention of waste products in the blood, and leakage of proteins
Examples:
Poststreptococcal infection: formation of immune complexes comprised of antistreptococcal antibodies and soluble streptococcal antigens; larger complexes become trapped into the glomerular capillaries inducing an inflammatory reaction
SLE: deposition of autoantibody-containing immune complexes in the glomeruli
IgA nephropathy: accumulation of immune complexes containing IgA with proliferation of mesangial cells, achromic and slowly progressive disease
Diabetic glomerulosclerosis: progressive renal damage in diabetes with nodular and diffuse thickening of the glomerular basement membrane and severe sclerosis of the glomerular arterioles Results in reduced glomerular blood flow, reduced urine formed, and leakage of protein