Microanatomy 3 Flashcards
what is the glomerular filtration barrier made up of
1, podcyte foot processes with filtration slit diaphragm
2, glomerular basement membrane
3, fenestrated endothelium of the capillary tuft
what causes glomerulonephritis
immune complex deposition int he glomerulus causes most types of glomerulonephritis
what is minimal change glomerulonephritis due to
- appears to be due to a cell mediated immune response
- happens to children under the age of 6 after a respiratory infection or immunisation
what form does damage to the glomerulus result in
- it elicits a glomerular response which may take one or more form these are
1. swelling and proliferation of the capillary endothelial cells
2, proliferation of the podocyte epithelial cells investing the glomerulus or parietal layer of the bowman capsule
3. thickening of the glomerular basement membrane
4, proliferation of cells of the mesangium and increased production of the mesangial matrix
what hisotlogical changes are shown due to glomerulonephritis
1, diffuse affecting all glomeruli
2, focal affecting some glomeruli
3, global the entire glomerulus is abnormal
4, segmental - only part of the glomerulus is abnormal
what is a percutaneous needle biopsy of the kidney
- this is a safe and reliable method to obtain tissue specimens for histopathological analysis in order to diagnose different forms of glomerulonephritis and other renal disease
what allows the differ nation between various forms and causes of glomerular disease
- immunofluorescence for immune and complement molecules
- electron micropscopy for various forms and causes of glomerular disease
what is acute proliferative glomerulonephritis
- this a diffuse (affecting all glomeruli) glomerulonephritis which most commonly occurs in children
- often present 1-4 weeks after a streptococcal infection of the pharynx or skin (impetigo) (other infections can cause it)
what is the hypercellularity of acute proliferative glomerulonephritis due to
- it is due to proliferation of endothelial and mesangial cells as well as infiltration by leucocytes mainly neutrophils
- endothelial swelling in addition to increased cellularity reduce the capillary lumina
how do you treat acute proliferative glomerulonephritis
95% of people recover totally with treatment aimed at maintaining water and sodium balance
describe what the glomerulus looks like in minimal change glomerulonephropahty
- podocyte foot processes are flattened onto the basement membrane
- immune complexes are absent
- selective proteinuria with mainly loss of albumin
how do you treat minimal change glomerulonephropathy
- treat with corticosteroid treatment
what causes the podocyte foot processes to flatten in minimal change glomerulonphropathy
- epithelial cell damage as a result of a number of insulting factors is through to cause podocyte cell foot processes to flatten
- results in a leaky glomerular filtration barrier
what is membranous glomerulopahty
- this is a form of chronic immune complex mediated disease and is a common cause of nephrotic syndrome in adults
- prepays due to autoimmunity and antibodies are reactive against a renal auto antigen, complement activation also plays a role and affects permeability of the glomerular filtration barrier
describe what membranous glomerulopathy looks like
- ## diffuse membrane thickening due to subepithelail deposition of electron dense immune complexes with thickens basement membrane spikes
what is the most common cause of end stage renal failure in the US and Europe
diabetes
what does glomerular disease manifest as first and then progress to
manifests first as proteinuria and then leads to nephrotic syndrome
what has a role in glomerular disease
- hyperglycaemia that you get in diabetes
how does hyperglycaemia from debates effect glumarul disease
- increases severity
- causes intimal capillary wall thickening
- mesangial matrix expansion
- diffuse diabetic glomerulosclerosis
- arterial atherosclerosis leading to the reduction in blood flow to the glomeruli
- this can lead to ischemia which leads to chronic renal failure
what is the most common primary kidney tumour
renal cell carincoma - this is an adenocarcinoma derived from tubular epithelial cells that accounts for 90% of kidney timorous
where is renal cell carincoma derived from
derived from tubular epithelial cells
what accounts for 5-10% of primary renal tumour
- transitional cell carcinomas which originate form the renal pelvis
- they are the most common malignant bladder tumour
where do transitional cell carcinomas originate from
- originate form the renal pelvis
describe nephroblastoma or wilms tumour
- rare
- children between age of 1-4 affected
- embryological origin
- called small round blue cell tumour
what do renal carcinomas have a tendency to do
invade the renal vein
where is transitional cell epithelium (uroepithelium) found
- it is only found in the urinary tract
describe transitional cell epithelium (uroepithelium)
- it is distended and urine cannot leak through it
- has a thick plasma membrane and plaques these all rounding and flattening of the cells which allow distension
- tight junctions between cells prohibit passage of water or other materials between the cells
what does transitional cell carcinoma often present with
- it often present with papillary growth
what can bladder cancer arise from
- transitional epithelium
- squamous epithelium
what diseases is membranous glomerulonephritis associated with
causes
Infective - Hep B, Malaria, syphulis
drug related - gold therapy, penicillamine, captorpil, heroin
tumour associated - bronchial carcinoma and lymphoma
autoimmune - systemic lupus erythematousus
what haematological abnormalities do you get as a result of renal cell carcinoma
anaemia
polycythameia - EPO production decreased