Renal Pathology Flashcards

Question

What is Hypertension & the Kidney?

Answer 1

In long standing hypertension, the following effects occur to the renal vessels which eventually leas to a reduced blood flow to the glomeruli: Renal artery branches show thickening of the wall due to a combination of muscular hypertrophy of the media, fibroelastic intimal proliferation & elastic lamina reduction. Afferent arterioles muscular walls become replaced by an amorphous material which is rigid & inelastic. Thickening of the vessel wall leads to a reduction in the size of the lumen & therefore: reduced blood flow. Chronic progression reduction in blood flow leads to chronic ischemia eventually leads to necrosis of nephrons leads to reduction of GFR Eventually sufficient numbers of nephrons are non- functioning and patients develop chronic renal failure. this process is termed hypertensive nephrosclerosis. this is in an important complication of long standing hypertension!

Answer 2

The glomerulus is the target of many disease processes which can lead to either: temporary or permanent impairment of function It can be damaged by: Generalised vascular disease  hypertension Immunological disorders Amyloid deposits

Answer 3

a term used to describe the group of diseases in which the primary pathology is some sort of structural, abnormality in the glomerulus. Most cases of glomerulonephritis are caused by another diseases such as SLE which leads to antigen- antibody complexes forming and being deposited in the glomerulus Damage to the glomerulus can cause scarring which can leads to associated tubule atrophy. Glomerular diseases can affect the glomeruli in varying degrees. This explains why some glomerular disease can cause sudden acute renal failure, whilst others only cause partial renal failure

Answer 4

structural changes to the glomerular basement membrane lead to nephrotic syndrome ( increased loss of protein in urine) glomerular damage associated with proliferation of endothelial cells leads to nephritic syndrome (blood in urine) Damage to both glomerular basement membrane & cell proliferation Mixed Nephrotic / Nephritic Syndrome Damage to glomeruli is rapid & widespread  Acute Renal Failure

Answer 5

Uncontrolled Diabetes is one of the most common causes of end stage kidney disease. particularly Type 2 due to associated vascular disease Vascular Disease in Diabetics (uncontrolled): Diabetics can have particularly severe atheromatous disease which involves large, medium and small branch arteries. Intimal thickening of atheroma leads to reduction in lumen size leads to poor glomerular perfusion by blood Reduced GFR Ultimately glomerular ischaemia. In diabetes, the kidney is particularly prone to acute bacterial infection known as acute pyelonephritis this affects the tubules and interstitium this predisposed renal papillary necrosis

Answer 6

Inflammation of the tubules & Interstitium caused by bacteria. (usually E.Coli but can be other bacteria) Bacteria enter in 1 of 2 ways: Lower Urinary Tract common causes: Diabetes pregnancy, enlarged prostate 2. Bloodstream Far less common, but can occur in elderly patients in septicemic states. Symptoms Back Pain Fever UTI symptoms if untreated can lead to: Acute renal failure, septicaemia, papillary necrosis.

Answer 7

Obstruction can impair drainage of urine from the kidney which causes hydronephrosis. Obstruction can occur anywhere in the tract: Renal Pelvis Ureter Bladder Urethra Obstruction can be either due to calculi, tumour, or extrinsic compression such as during pregnancy

Answer 8

These can form anywhere in the lower urinary tract most commonly the bladder and pelvicalyceal system. Formed by persistently abnormal urinary pH or increased solutes in urine. Conditions that predispose renal calculi are: Low fluid intake persistent urinary tract infections primary metabolic disturbances 4 main types: Caclium Oxalate and phopphate calculi (most common- 80% of cases) can be associated with inflammatory bowel disease Magnesium Ammonium Phsosphate (15% of cases) associated with UTIs Uric Acid Calculi (5% of cases) Cystine Calculi (rare – less than 1% of cases)

Answer 9

Most common disorder of the prostate Affects almost all men over the age of 70 Found with increasing frequency & severity from the age of 45 and upwards Clinical Presentation Difficulty with micturition Frequent need to urinate through the night Symptoms are due to: Enlarging prostate compresses the urethra most commonly the lateral lobes of the prostate In some cases, the posterior lobe enlarges which can greatly obstruct the bladder neck. Prolonged prostatic obstruction can lead to marked hypertrophy of the bladder wall, and can affect retention of urine. this increases risk of infection. Cause is not fully understood It is believed it may be due to androgen – oestrogen imbalance which causes prostate gland to undergo hyperplasia.

Answer 10

Most common malignant tumour in men. Tumour arises in the peripheral glands and can invade urethra Often prostatic cancer is well established before symptoms such as difficulty wit micturition occur. Therefore, screening to detect early stage prostate cancer is important test for Prostate Specific Antigen (PSA)

Answer 11

The kidneys continuously filter waste products, allow reabsorption of certain components back into the blood stream. they filters approx. 1100- 1200ml of blood per minute known as glomerular filtration rate Therefore, most diseases of the kidneys will be associated with abnormalities of either the blood vessel system or the epithelial lined tubule system- or both. The kidney is particularly vulnerable to vascular disease such as: consequences of atheroma & vessel abnormalities associated with diabetes mellitus and hypertension. The kidneys are also sensitive to several types of immune reactions in where immune complexes are deposited on the walls of the blood vessels forming the glomerulus this group of disorders are called the “glomerulonephritidies” the kidneys are very metabolically active & so are extremely vulnerable to hypoxia & necrosis of epithelial cells which is the most common cause of acute renal failure. The urinary tract is predisposed to bacterial infection known as pyelonephritis. Urine is a concentrated solution of solutes, which sometimes form calculi and can obstruct the urinary system.

Answer 12

Part of the kidney that filters blood