CCMA Training Notes: Urinary System

Urinary system  

Anatomy  

The Urinary System  

Kidneys: There are two of them that are bean-shaped structures that connect the urinary system to the cardiovascular system. They filter the blood to remove waste products of metabolism and excess water. Eventually, these wastes are excreted in the urine. The kidneys filter (on average) around 200 quarts of blood each day to produce about two quarts of urine. Many factors determine the amount of urine produced.  

Ureters: They are narrow tubes about 10 to 12 inches long and transport the urine from the kidneys to the ureter bladder.  

Urinary Bladder: It is an oval, hollow, muscular organ that serves as a storage tank for the urine before it is eliminated from the body. It is in the anterior part of the pelvic cavity behind the pubic symphysis. The average adult bladder stores over a pint of urine.  

Urethra: This tube extends from the bladder to the exterior of the body. There is a urethral sphincter at each end of the uretha that allows controlling the elimination of the urine.  

In females it is about 1.5 inches long and exits the body through the urethral meatus located between the clitoris and the opening of the vagina. 

In males it is about 8 inches long with the urethral meatus located at the tip of the penis. It transports both urine and semen and is surrounded by the prostate gland.  

The Kidneys  

Renal cortex: Each kidney has one on the outside and it contains over a million microscopic cells called nephrons.  

Renal medulla: Each kidney has one on the inside.  

Tubules: The medulla contains these which collect urine.  

Renal Artery: It brings blood into the kidney and ultimately the nephrons after passing through the filtration system of the glomerulus, the filtered blood leaves the kidney and returns to the bloodstream through the renal vein.  

Renal Pelvis: Is the funnel-shaped area inside each kidney surrounded by the renal cortex and medulla. This is where the renal artery and vein enter and exit the kidney.  

Physiology 

Homeostasis: The filtering of blood waste products of metabolism and eliminating excess water has the goal of maintaining this which is also known as balance in the body.  

Afferent Arteriole: Blood from the body is brought into the kidney via the renal artery which becomes smaller to become the afferent arteriole.  

Glomerulus: Blood enters the nephron through this cluster of capillaries surrounded by a cup-shaped membrane called the Bowman’s capsule and the renal tubule. This is the filtration system of the nephron.  

Renal Vein: After passing through the filtration system of the glomerulus, the filtered blood containing protein and blood cells leave the kidney and return to the bloodstream through the renal vein.  

Filtrate: This or the substances and water removed from the blood, flows into the renal tubules.  

The substances needed by the body that return to the bloodstream: water, sugar, and salts.  

Everything else that is waste products are converted into urine which is then transported to the renal pelvis to be collected so that they can be moved to the ureters and eventually to the urinary bladder and out via the urethra.  

This urine formation can be described in 4 urinary processes: 

Common Diseases and Disorders 

Nephropathy: Refers to any disease of the kidney including degenerative conditions and inflammatory conditions.  

Diabetic Nephropathy: Is a kidney disease resulting from late-stage diabetes mellitus.  

Renal Failure: Is also called kidney failure. This is the inability of one or both kidneys to function. Unfortunately, the body cannot replace damaged nephrons. When too many nephrons are damaged, the kidneys stop working. The body cannot live without the functions of the kidneys.  

Uremia: This refers to uremic poisoning, or a toxic condition resulting from renal failure. Waste products normally secreted in the urine build up in the body.  

Acute Renal Failure: This refers to a sudden onset of renal failure caused by a sudden drop in blood volume or blood pressure to the kidneys.  

Chronic Kidney Disease: This is a progressive loss of renal function over months or years and it is life-threatening.  

End-Stage Renal Disease (ESRD): This is the final stage of chronic kidney disease and is fatal unless dialysis replaces the normal functions of the kidneys or the kidneys are replaced via a transplant.  

Nephrotic Syndrome: Is referred to as nephrosis and is a group of conditions in which too much protein is lost through the urine. It is caused by damage to the glomeruli.  

Edema: Refers to excessive fluid accumulation in body tissue and is a common symptom of nephrotic syndrome and other kidney diseases.  

Hyper proteinuria: Refers to an abnormally high concentration of protein in the urine.  

Hypoproteinemia: Refers to an abnormally high concentration of protein in the blood.  

Kidney Disorders:  

Hydronephrosis: Refers to the dilation or swelling of one or both kidneys. It can be caused by the backing up of urine by an obstruction, such as a kidney stone, or by the narrowing of the ureter.  

Nephritis: Refers to inflammation of the kidney.  

Glomerulonephritis: Is a type of nephritis caused by inflammation of the glomeruli causing red blood cells and protein to leak into the urine.  

Polycystic Kidney Disease: Refers to a genetic disorder where the growth of many fluids filled cysts in the kidney. The cysts replace the kidney mass reducing the kidney function.  

Renal Colic: Refers to an acute pain in the kidney arae causing blockage during the passage of a kidney stone.  

Whims tumor: This is a rare malignant tumor of the kidney occurring in children. 

Kidney Stones: Refers to abnormal mineral deposits that have formed within the kidney as a result of waste products in the urine separating then crystalizing or other factors such as dehydration. They are also called calculoses. They vary in size from small sand-like granules to very large so that they can become lodged and cause severe pain.  

Nephrolithiasis: The condition where there is presence of stones in the kidney. They travel with the flow of urine and can become lodged at any place in the path from the kidney through the urethra.  

Nephrolith: This is a stone in the kidney.  

Ureterolith: This is a stone in the ureter.  

Cystolith: This is a stone in the urinary bladder.  

Disorders of the Ureters:  

Hydroureter: Refers to the distension or swelling of the ureter with urine that is prevented from flowing out due to a blockage.  

Ureter ectasis: Refers to the distension or swelling of a ureter because of congenital abnormalities.  

Urethrorrhagia: Refers to a discharge of blood from the ureter.  

Disorders of the Urinary Bladder:  

Cystocele: Referred to as a prolapsed bladder and it is a hernia of the bladder through the vaginal wall which is sometimes a result of pregnancy and childbirth.  

Interstitial Cystitis: Refers to chronic inflammation within the walls of the bladder.  

Cystalgia: Refers to pain in the bladder.  

Vesicoureteral Reflux: Refers to the backward flow of urine into the ureters from the bladder.  

Neurogenic Bladder: Refers to a urinary condition in which there is interference with the normal nerve pathway that controls urination therefore preventing the bladder from emptying at all or completely.  

Normally: the nerves should sense when the bladder is full and then control the muscles that either retain the urine or allow the bladder to empty.  

Result: overflow leakage because of urinary retention.  

Causes: Possible tumor, trauma, neuropathy, or inflammation.  

Disorders of the Prostate Gland:  

Benign Prostatic Hyperplasia: This is commonly called an enlarged prostate, and it is referred to an enlargement of the prostate gland occurring mainly in men over 50. It makes urination difficult causing urinary-tract problems.  

Prostatism: This is a disorder resulting from the compression or obstruction of the urethra because of benign prostatic hyperplasia. It leads to difficulties with urination.  

Prostate cancer: This is one of the most common cancers in men. It can grow very slowly with no symptoms or grow aggressively and spread to other parts of the body.  

Prostatitis: This is a group of disorders where there is inflammation of the prostate gland.  

Disorders of the Urinary Tract:  

Cystitis: This refers to an inflammation of the bladder.  

Pyelonephritis: This refers to an inflammation of both the renal pelvis and kidney. It is typically caused by a bacterial infection that spreads upward from the bladder.  

Urethritis: This refers to an inflammation of the urethra.  

Anuria: This is the term describing the absence of urine formation by the kidneys. 

Diuresis: Refers to the increased output of urine.  

Dysuria: Refers to difficult or painful urination.  

Enuresis: Refers to involuntary discharge of urine.  

Nocturnal Enuresis: Is the urinary incontinence during sleep and it is commonly called bed-wetting.  

Nocturia: Refers to frequent and excessive urination during the night.  

Oliguria: Refers to scanty urination often caused by dehydration, renal failure, or perhaps an obstruction of the tract.  

Polyuria: Refers to excessive urination. It is associated with diabetes.  

Urinary Hesitancy: Refers to difficulty in starting a urinary stream.  

Incontinence: Refers to the inability to control the excretion of urinary.  

Overflow Incontinence: Is a continuous leaking from the bladder because it is full or it has not completely emptied.  

It can be caused by physical stress such as running or lifting, sneezing, laughing, or coughing.  

Overactive Bladder: This occurs when the muscles of the bladder contract involuntarily even if the bladder is not full.