Kidneys-ch 20 Flashcards
The mesonephric duct forms what in the adult kidney?
Ureter, pelvis, calyces, and collecting tubules
Why is the renal medulla particularly vulnerable to ischemia?
The medulla is relatively avascular, and the blood in the capillary loops in the medulla has a remarkably low hematocrit value.
The nephron is the basic structural and functional unit of the kidney. What are the components of the nephron?
Glomerulus enclosed within Bowman capsule, and its attached tubule, consisting of the proximal convoluted portion, loop of Henle, and distal convoluted portion
What are the two major characteristics of the glomerular filtration?
The major characteristics of glomerular filtration are an extraordinary high permeability to water and small solutes, accounted for by the highly fenestrated endothelium, and impermeability to proteins.
What are the three components of the juxtaglomerular apparatus?
Juxtaglomerular cells, macula densa, and nongranular cells (
google:
The juxtaglomerular apparatus (also known as the juxtaglomerular complex) is a structure in the kidney that regulates the function of each nephron, the functional units of the kidney. The juxtaglomerular apparatus is named because it is next to (juxta-[1]) the glomerulus.
The juxtaglomerular apparatus consists of three types of cells:
the macula densa, a part of the distal convoluted tubule of the same nephron
juxtaglomerular cells, (also known as granular cells) which secrete renin
extraglomerular mesangial cells (i think this is the same as nongranular cells)
Glomerular diseases are frequently _____ mediated while tubular and interstitial diseases are more likely to be caused by _____ or _____.
Immunologically
Toxic or infectious agents
Define azotemia and list the causes of pre-renal azotemia and post-renal azotemia
definition:Portal vein and hepatic artery Azotemia is a biochemical abnormality that refers to an elevation of the blood urea nitrogen and creatinine levels and is largely related to decreased glomerular filtration rate.
Pre-renal azotemia is encountered where there is hypoperfusion (reduced blood flow) of the kidneys that impairs renal function in the absence of parenchymal damage.
Post-renal azotemia is seen whenever urine flow is obstructed beyond the level of the kidney.
google: Azotemia and uremia are two different types of kidney conditions. Azotemia is when there’s nitrogen in your blood. Uremia occurs when there’s urea in your blood. However, they’re both related to kidney disease or injury.
Distinguish between nephrotic and nephritic syndromes.
Nephritic syndrome is a glomerular syndrome dominated by the acute onset of usually grossly visible hematuria, mild to moderate proteinuria, and hypertension; it is the classic presentation of acute poststreptococcal glomerulonephritis.
Nephrotic syndrome is characterized by heavy proteinuria (more than 3.5 gm/day), hypoalbuminemia, severe edema, hyperlipidemia, and lipiduria
google:
NEPHROTIC = PROTEIN; NEPHRITIC = BLOOD
The key with nephrotic syndrome is an excess amount of protein in the urine, whereas nephritic syndrome is where there is an excess amount of blood in the urine.
hint O in protein and O in nephrotic
Describe the four stages of chronic renal failure.
Diminished renal reserve – GFR is about 50% of normal
Renal insufficiency – GFR is 20 –50% of normal
Renal failure – GFR is less than 20 – 25% of normal
Endstage renal disease – GFR is less than 5% of normal
A true hypoplastic kidney will show what characteristics?
A truly hypoplastic kidney should show no scars, and should possess a reduced number of renal lobes and pyramids, 6 or fewer.
A patient who has an ectopic kidney is predisposed to bacterial infections of the kidney. Where are the ectopic kidney rests commonly located?
just above the pelvic brim or sometimes within the pelvis.
google:
An ectopic kidney, also known as renal ectopia, is a congenital renal anomaly characterized by the abnormal location of one or both of the kidneys.
horseshoe kidney is commonly found where?
90% lower pole
10% upper pole
google: Horseshoe kidney is a condition in which the kidneys are fused together at the lower end or base. By fusing, they form a “U” shape,
What chromosomal aberration is associated with autosomal dominant polycystic kidney disease?
How is renal function maintained in this condition and what are some other associated conditions? PKD1 gene located on chromosome 16p13.3 accounts for about 85% of cases and encodes a large (460kD) protein named polycystin 1. Renal function is maintained until the 4th or 5th decade of life because cysts initially involve only portions of the nephrons. About 40% of patients with PKD have polycystic liver disease. Berry aneurysms and subarachnoid hemorrhages account for death in 4-10% of patients with PCKD. PKD2 gene is located on 4q21.
Briefly describe the gross appearance of autosomal recessive polycystic kidney disease?
The kidneys are enlarged and have a smooth external appearance. On cut section, numerous small cysts in the cortex and medulla give the kidney a sponge-like appearance. Dilated elongated channels are present at right angles to the cortical surface, completely replacing the medulla and cortex.
What are the three most common forms of glomerular disease and list the four major tissue reactions that occur in this disease?
Primary glomerulopathies, systemic diseases with glomerular involvement, hereditary disorders
Reactions – hypercellularity, basement membrane thickening, hyalinization, and sclerosis (abnormal hardening of body tissue )
in circulating immune complex nephritis, the antigen sources are either exogenous or endogenous.
Exogenous – glomerulonephritis that follows certain infections
Endogenous – glomerulopathy associated with systemic lupus erythematosus
what is the pathogenesis of antiglomerular basement membrane antibody-induced glomerulonephritis , what is the characteristic immunofluorescent staining pattern
Antibodies are directed against intrinsic fixed antigens that are normal components of the glomerular basement membrane proper.
Staining pattern – homogeneous, diffuse linear pattern
What are the differences in clinical presentation of post-streptococcal glomerulonephritis in children and adults (clinical presentation)? What is the classic diagnostic picture of acute post-streptococcal glomerulonephritis?
A child abruptly develops malaise, fever, nausea, oliguria, and hematuria one to two weeks after recovery from a sore throat. The patients exhibit red cell casts in the urine, mild proteinuria, periorbital edema, and mild to moderate hypertension.
In adults, the onset is more likely to be atypical, with the sudden appearance of hypertension or edema, frequently with elevation of BUN.
The classic diagnostic picture is one of diffusely enlarged, hypercellular glomeruli with leukocyte infiltration, proliferation of endothelial and mesangial cells, and in severe cases, by crescent formation.
google: Post-streptococcal glomerulonephritis (gloe-mer-u-low-nuh-FRY-tis) — or PSGN — is a rare kidney disease that can develop after group A strep infections
What is Goodpasture syndrome and why does the disease affect the lungs as well as the kidneys? What is the immunofluorescent staining pattern?
Goodpasture syndrome is the simultaneous appearance of proliferative, usually rapidly progressive glomerulonephritis and a necrotizing hemorrhagic interstitial pneumonitis. Anti-GBM antibodies cross-react with other basement membranes, especially those in the lung alveoli, resulting in simultaneous lung and kidney lesions. The staining pattern is linear IgG and C3; in crescents.
What is the immunofluorescent staining pattern in membrane proliferative glomerulonephritis?
Granular IgG and C3; diffuse
in the question the pic is granular and here its diffuse
google:
Describe the differences between Type I and Type II membranoproliferative glomerulonephritis?
Type I MPGN is characterized by the presence of discrete subendothelial electron dense deposits.
Type II MPGN – the lamina densa of the glomerular basement membrane is transformed into an irregular, ribbon-like, extremely electron-dense structure because of the deposition of dense material of unknown composition in the glomerular basement membrane proper, giving rise to the term dense-deposit disease.
Membranoproliferative glomerulonephritis (MPGN) is a disease that affects the glomeruli, or filters, of the kidneys. Most instances of MPGN are caused by other diseases or disorders,
type I- Discrete immune complexes are found in the mesangium and subendothelial space. Immune complexes are combinations of antigens and antibodies which bind to each other and then become lodged in the kidney. This activates the immune system, which causes inflammation and damage to the kidney itself.
Type II – This is also called dense deposit disease. When viewed under the microscope, continuous, dense ribbon-like deposits are found along the basement membranes of the glomeruli, tubules, and Bowman’s capsule.
What are the components of the syndrome Henoch-Schönlein-Purpura and what are the renal manifestations?
Purpuric skin lesions, abdominal manifestations, nonmigratory arthralgias, and renal abnormalities Renal manifestations – gross and microscopic hematuria, proteinuria, and nephritic syndrome
Describe the characteristic lesions of the two patterns of acute tubular injury.
Ischemic acute tubular injury is characterized by focal tubular epithelial necrosis and apoptosis at multiple points along the nephron, with large skip areas in between, often accompanied by rupture of basement membranes and occlusion of tubular lumens by casts.
Toxic acute tubular injury is manifested by acute tubular injury, most obvious in the proximal convoluted tubules.
google;
picture : Acute tubular necrosis. Photomicrograph of a kidney biopsy specimen shows renal medulla, which is composed mainly of renal tubules. Features suggesting acute tubular necrosis are the patchy or diffuse denudation of the renal tubular cells with loss of brush border (blue arrows); flattening of the renal tubular cells due to tubular dilation (orange arrows); intratubular cast formation (yellow arrows); and sloughing of cells, which is responsible for the formation of granular casts (red arrow). Finally, intratubular obstruction due to the denuded epithelium and cellular debris is evident (green arrow); note that the denuded tubular epithelial cells clump together because of rearrangement of intercellular adhesion molecules.
What are the methods of bacterial propagation into the renal pelvis and the renal parenchyma?
Vesicoureteral reflux and intrarenal reflux
google:
Vesicoureteral (ves-ih-koe-yoo-REE-tur-ul) reflux is the abnormal flow of urine from your bladder back up the tubes (ureters) that connect your kidneys to your bladder
Intrarenal reflux (IRR) involves intrarenal extension of vesicoureteral reflux (VUR) into the tubular system of the kidney
Define chronic pyelonephritis and describe characteristic gross and micro features.
Chronic pyelonephritis is a chronic tubulointerstitial disorder in which chronic tubulointerstitial inflammation and renal scarring are associated with pathologic involvement of the calyces and pelvis.
Gross – Irregularly scarred, coarse, discrete corticomedullary scars overlying dilated, blunted, or deformed calyces and flattening of the papillae
Micro – Thyroidization of tubules with varying degrees of chronic interstitial inflammation and fibrosis (p. 933-934)
google:
The phrase ‘chronic pyelonephritis’ (CP) is not really one diagnosis. It is meant to mean the long-term damage done by recurrent urine infection to the drainage system of the kidney. But it has come to be a ‘fallback diagnosis’, i.e. when doctors are not sure of the cause of kidney failure, and the kidney has scars on its surface, they call it CP.
The cause of CP is unclear, partly because the condition may exist with no evidence of infection. It can be caused by reflux nephropathy, in which the kidneys are damaged by the backward flow of urine into the kidney - due to a leaky valve between the bladder and the ureter.
What is xanthogranulomatous pyelonephritis and what is it commonly associated with?
Xanthogranulomatous pyelonephritis is an unusual and relatively rare form of chronic pyelonephritis characterized by accumulation of foamy macrophages intermingled with plasma cells, lymphocytes, polymorphonuclear leukocytes, and occasional giant cells. Often associated with Proteus infections and obstruction. Large yellowish-orange nodules grossly may be confused with renal cell carcinoma.
google:
Most cases occur in the setting of obstruction due to infected renal stones , often confused with RCC
What is the most common primary renal tumor in children?
Wilms tumor
google: Nephroblastomas /wilms tumor are usually solitary, large, and sharply demarcated tumors. The bulging cut surface is soft, fleshy, lobulated, yellow-tan, and frequently has areas of hemorrhage, necrosis, or cyst formation.
