Removes metabolic wastes, hormones, drugs and other foreign material from the body
Regulates water, electrolyte, acid-base balance
Secretes erythropoietin
Activates vitamin D
Regulates blood pressure through the renin-angiotensin-aldosterone system
Urinary System organs in order
1. Kidneys
2. Ureters
3. Urinary bladder
4. Urethra
Kidney
Nephrons are the functional units
Each kidney has over a million nephrons
Nephron in order
1. Renal corpuscles
2. Glomerulus
3. Bowman capsule
4. Renal tubules
5. Proximal convoluted tubules
6. Loop of Henle
7. Distal convoluted tubules
8. Collecting duct
Antidiuretic hormone (ADH)
Secreted by the posterior pituitary, reabsorbs water in distal convoluted tubules and collecting ducts
Aldosterone
Secreted by adrenal cortex, reabsorbs sodium in exchange for potassium or hydrogen
Atrial natriuretic hormone
Hormone from the heart, reduces sodium and fluid reabsorption
Glomerular Filtration Rate (GFR) control
1. Autoregulation
2. Sympathetic nervous system
3. Renin-angiotensin mechanism
Incontinence
Loss of voluntary control of the bladder
Enuresis
Involuntary urination by child age older than 4 years
Stress incontinence
Happens when physical movement or activity puts pressure on the bladder, causing urine leakage
Overflow incontinence
You have the urge to urinate but can release only a small amount
Incompetent bladder sphincter
The muscles and tissues that control the release of urine from the bladder are weakened or damaged, leading to involuntary urine leakage
Retention
Inability to empty bladder, may be accompanied by overflow incontinence
Urinalysis: Appearance of Urine
Straw colored with mild odor is normal
Cloudy may indicate presence of large amounts of protein, blood, bacteria, and pus
Dark color may indicate hematuria, excessive bilirubin, or highly concentrated urine
Unpleasant or unusual odor may indicate infection or result from certain dietary components or medication
Urinalysis: Urinary Infection
Heavy purulence and presence of gram-negative and gram-positive organisms
Abnormal Constituents of Urine
Blood (hematuria)
Elevated protein level (proteinuria, albuminuria)
Bacteria (bacteriuria)
Urinarycasts
Urinary casts are tiny tube-shaped particles that can be found when urine is examined under the microscope during a urinalysis. Urinary casts may be made up of white blood cells, red blood cells, kidney cells, or substances such as protein or fat. The content of a cast can help tell your health care provider whether your kidney is healthy or abnormal.
Elevated serum urea and serum creatinine levels
Indicate failure to excrete nitrogen wastes, caused by decreased GFR
Metabolic acidosis
Indicates decreased GFR and failure of tubules to control acid-base balance
Anemia
Indicates decreased erythropoietin secretion and/or bone marrow depression
Elevated renin levels
Indicate kidney as a cause of hypertension
Clearance tests
Examples: creatinine or inulin clearance, used to assess GFR
Cystoscopy
Visualizes lower urinary tract, may be used to perform biopsy or remove kidney stones
Diuretic drugs
Used to remove excess sodium ions and water from the body, increase excretion of water through the kidneys, reduce fluid volume in tissues and blood
Dialysis
1. Hemodialysis
2. Peritoneal dialysis
Hemodialysis
Exchange of wastes, fluids, and electrolytes, blood cells and proteins remain in blood, blood returned to patient's vein
Peritoneal Dialysis
Takes more time than hemodialysis, major complication is infection resulting in peritonitis
Disorders of the Urinary System
Urinary Tract Infections
Cystitis and Urethritis
Pyelonephritis
Glomerulonephritis
Nephrotic Syndrome
Urinary Tract Infections (UTIs)
Very common infections, urine is an excellent growth medium
Lower urinary tract infections
Cystitis (inflammation of the bladder)
Urethritis (urethra becomes swollen and sore)
Cystitis and Urethritis
Bladder wall (cystitis) and urethra (urethritis) are inflamed, causes pain, dysuria, urgency, frequency, and nocturia
Pyelonephritis
One or both kidneys involved, purulent exudate fills pelvis and calyces, recurrent or chronic infection can lead to scar tissue formation and eventual chronic renal failure if untreated
Glomerulonephritis
A group of diseases that injure the glomeruli, presence of antistreptococcal (ASO) antibodies, causes inflammatory response in glomeruli
Glomerulonephritis symptoms
Urine becomes dark and cloudy, facial and periorbital edema, elevated blood pressure, flank or back pain, decreased urine output
Blood tests in glomerulonephritis show elevated serum urea and creatinine levels, and metabolic acidosis. Urinalysis shows proteinuria, hematuria, and erythrocyte casts.
Hyperactive bladder and reduced capacity
Pain is common in pelvic area
Dysuria
Painful Urination, urgency, frequency, and nocturia