Practical of Histopathology

Medical Renal Biopsy

Objectives Handling of the Medical Renal Biopsy. Understanding some renal diseases. Evaluation of the Renal Biopsy by light microscopy

Introduction The urinary system, also known as the renal system, consists of the kidneys, ureters, bladder, and the urethra. Each kidney consists of millions of functional units called nephrons.   urethraالإحليل هو قناة تربط المثانة إلى خارج الجسم. للإحليل وظيفة اخراجية في الجنسين ...

The adrenal glands, located at the top of each kidney

Overview Renal disease is frequent in the USA: Approximately 8×10*6 individuals have chronic renal disease. Kidney biopsy remains the gold standard for the diagnosis and treatment of medical renal disease occurring in both native and transplanted kidneys.

Cont… In particular, kidney biopsy can be used to evaluate the type, extent, site, and nature of renal involvement in a disease.

Cont… Renal biopsy is a relatively low-risk procedure. The pattern of light microscopic injury in the renal biopsy is typically the major clue to diagnosis. Each biopsy is therefore evaluated for changes in glomeruli, tubules, interstitium, and vessels to arrive at a preliminary (and often final) diagnosis. Nephron definition, the filtering and excretory unit of the kidney, consisting ofthe glomerulus and tubules. See more. A glomerulus is a network (as a tuft) of capillaries located at the beginning of a nephron in the ... The Bowman's capsule empties the filtrate into the proximaltubule that is also part of the duct system of the nephron. A glomerulusreceives its ...

Cont… The diagnosis of renal biopsies is complex, requiring correlation of the findings in three modalities: light, immunofluorescence, and electron microscopy.

location

Functions Removal of waste product from the body (mainly urea and uric acid). Regulation of electrolyte balance (e.g. sodium, potassium and calcium). Regulation of acid-base homeostasis. Controlling blood volume and maintaining blood pressure.

Filtration Inside each kidney are around a million tiny structures called nephrons. The nephron is the functional unit of the kidney that filters blood to produce urine. Arterioles in the kidneys deliver blood to a bundle of capillaries surrounded by a capsule called a glomerulus.

Cont… As blood flows through the glomerulus, much of the blood’s plasma is pushed out of the capillaries and into the capsule, leaving the blood cells and a small amount of plasma to continue flowing through the capillaries..

Cont… The liquid filtrate in the capsule flows through a series of tubules lined with filtering cells and surrounded by capillaries. The cells surrounding the tubules selectively absorb water and substances from the filtrate in the tubule and return it to the blood in the capillaries.

Cont… At the same time, waste products present in the blood are secreted into the filtrate. By the end of this process, the filtrate in the tubule has become urine containing only water, waste products, and excess ions.

Cont… The blood exiting the capillaries has reabsorbed all of the nutrients along with most of the water and ions that the body needs to function.

Storage and Excretion of Wastes After urine has been produced by the kidneys, it is transported through the ureters to the urinary bladder. The urinary bladder fills with urine and stores it until the body is ready for its excretion.

Cont… When the volume of the urinary bladder reaches anywhere from 150 to 400 milliliters, its walls begin to stretch and stretch receptors in its walls send signals to the brain and spinal cord.

Cont… These signals result in the relaxation of the involuntary internal urethral sphincter and the sensation of needing to urinate. Urination may be delayed as long as the bladder does not exceed its maximum volume, but increasing nerve signals lead to greater discomfort and desire to urinate.

Cont… Urination is the process of releasing urine from the urinary bladder through the urethra and out of the body. The process of urination begins when the muscles of the urethral sphincters relax, allowing urine to pass through the urethra.

Cont… At the same time that the sphincters relax, the smooth muscle in the walls of the urinary bladder contract to expel urine from the bladder.

Diseases of the urinary system

(infection of kidney pelvis) Glomerulonephritis Pyelonephritis (infection of kidney pelvis) Nephritic syndrome Kidney stones (nephrolithiasis) Acute renal failure (kidney failure) Polycystic kidney disease End stage renal disease Chronic renal failure Diabetic nephropathy Papillary necrosis Kidney cancer Hypertensive nephropathy Minimal change disease Interstitial nephritis Renal cyst Nephrogenic diabetes insipidus

Glomerulonephritis An overactive immune system may attack the kidney, causing inflammation and some damage. Blood and protein in the urine are common problems that occur with glomerulonephritis. It can also result in kidney failure.

Polycystic kidney disease A genetic condition resulting in large cysts in both kidneys that impair their function.

Papillary necrosis Severe damage to the kidneys can cause chunks of kidney tissue to break off internally and clog the kidneys. If untreated, the resulting damage can lead to total kidney failure.

Kidney cancer Renal cell carcinoma is the most common cancer affecting the kidney. Smoking is the most common cause of kidney cancer.

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