Functions of the Urinary System Maintains the proper balance of water, salts, and acids in the body fluids by removing excess fluids from the body or reabsorbing water as needed. Constantly filters the blood to remove urea and other waste materials from the bloodstream. Urea is the major waste product of protein metabolism.
Converts these waste products and excess fluids into urine. KIDNEYS: (nephr/o, ren/o) Renal pelvis: inside the kidney. Word root = pyel/o.
Waste products pass through a series of urine-collecting tubules and are transported to the renal pelvis before entering the ureters. Renal cortex: outer layer of kidney. Medulla: inner layer of the kidney; contains most of the urine-collecting tubules.
Nephrons: the functional units. They form urine by the processes of filtration, reabsorption & secretion. Each nephron contains a glomerulus – a cluster of capillaries surrounded by a membrane called the Bowman’s capsule.
Blood flows into the kidney through the renal artery. Then, it is filtered and leaves through the renal vein. Waste products pass through a series of urine-collecting tubules and are transported to the renal pelvis before entering the ureters.
urochrome is the pigment that gives urine its yellow-amber or straw color. ur/o = urine; -chrome = color. The color of urine can be influenced by normal factors such as the amount of liquid consumed or by diseases and medications.
Ureters (ureter/o) – narrow tubes 10- 12 inches long; carry urine from a kidney to the bladder. Bladder: (cyst/o) – is a reservoir for urine; holds about a pint of urine.
Urethra (urethr/o) Extends from the bladder to the outside of the body. Two urinary sphincters, one located at either end of the urethra, control the flow of urine. Female urethra: approx. 1.5 in. long Male urethra: approx. 8 in. long.; Neck is surrounded by prostate gland
Excreting Urine (ur/o = urine) As the bladder fills up, pressure is placed on the base of the urethra, resulting in the urge to urinate, or void, or micturate. Nephrologist – specializes in treatment of kidneys. Urologist – specializes in treatment of the urinary system.
Pathology of the Urinary System Renal failure, or kidney failure, is the inability of kidneys to perform properly. The body cannot replace damaged nephrons. anuria – complete suppression of urine formation (i.e. without urine) uremia – or uremic poisoning – excessive amounts of urea and other waste products in the bloodstream.
acute renal failure, or ARF – sudden onset; characterized by uremia. Causes include a drop in blood volume or blood pressure due to injury or surgery. chronic renal failure, or CRF, a progressive disease. Dialysis or kidney transplantation may be required.
End-stage renal disease, or ESRD – late stages of chronic renal failure. Nephrotic syndrome – a group of kidney diseases, including: edema – excessive fluid in body tissue
hyperproteinuria – high concentrations of protein (albumin) in the urine. hypoproteinuria low concentrations of protein in the urine. hyperlipidemia – large amounts of lipids in the blood.
Nephrosis / Nephropathy Diabetic nephropathy – damage to the kidney vessels caused by long-term diabetes.
Kidney Diseases glomerulonephritis – inflammation of the kidneys involving the glomeruli. Urine is dark brown or black; usually related to an autoimmune problem. hydronephrosis – dilation or enlargement of the renal pelvis due to an obstruction of the flow of urine.
nephrectasis – dilation / stretching of a kidney. nephritis – inflammation of a kidney. nephropyosis – formation of or discharge of pus in the kidney. pyelitis – inflammation of the renal pelvis. pyelonephritis – inflammation of the renal pelvis AND kidney.
Stones – (-lithiasis = presence of stones) A stone is also called a calculus. It is an abnormal mineral deposit. They vary in size from small sand-like granules to the size of marbles and are named for the organ or tissue where they are located. nephrolithiasis – presence of stones in the kidney.
Urinary tract infection, or UTI – usually begins in the bladder. More common in women due to shortness of the urethra. Is also referred to as a “bladder infection.”
Abnormal urethral openings: epispadias – male urethral opening is located on the dorsal (upper surface) of the penis. hypospadias – male urethral opening is located on the undersurface of the penis. paraspadias – male urethral opening is on the side of the penis.
Urination diuresis – increased excretion of urine dysuria – difficult or painful urination enuresis – involuntary discharge of urine. Nocturnal enuresis is known as bedwetting. nocturia – excessive urination during the night.
oliguria – scanty or very little urine. polyuria – excessive urination. urinary retention – inability to void or empty bladder, even if full. incontinence – inability to control excretion (urinary or bowel).
urinary stress incontinence – inability to control the voiding of urine under physical stress such as running, sneezing, laughing, or coughing. urinalysis – the examination of urine to determine the presence of abnormal elements.
Treatment Procedures dialysis – a procedure to remove waste products from the blood of patients whose kidneys no longer function. Two types: hemodialysis – filtering waste products from the patient’s blood. peritoneal dialysis – removes waste through fluid exchange in abdomen.
Diagnostic Procedures Catheterization is the insertion of a sterile catheter through the urethra into the urinary bladder. This is most commonly used to withdraw urine or prevent incontinence during surgical procedures.
Cystoscopy – the visual examination of the urinary bladder using a cystoscope. It can also be used for treatment procedures such as the removal of tumors.
IVP – intravenous pyelogram – a radiographic (X-ray) study of the kidneys and ureters in which iodine is injected into a vein as a contrast medium to define these structures more clearly.
KUB – (kidneys, ureters, bladder) – an X-ray study of these structures without the use of a contrast medium. It is also referred to as a “flat-plate of the abdomen”.