Urinary Systems Allied Health Science 1 Mrs. Lewis

Functions of the Urinary System Excretion- removing nitrogenous waste, certain salts and excess water from blood. Excretion- removing nitrogenous waste, certain salts and excess water from blood. Maintain acid-base balance Maintain acid-base balance Secrete waste products in the form of urine Secrete waste products in the form of urine Eliminate urine from bladder Eliminate urine from bladder

Kidneys Bean-shaped organs Bean-shaped organs Located b/w peritoneum and the back muscles Located b/w peritoneum and the back muscles Renal Pelvis- funnel shaped structure at the beginning of the ureter. Renal Pelvis- funnel shaped structure at the beginning of the ureter.

Medulla Inner, striated layer of the kidney Inner, striated layer of the kidney Triangular shaped division of the medulla are called Pyramids. Triangular shaped division of the medulla are called Pyramids. Base of the each pyramid faces cortex, while apex empties into cuplike cavities called Calycles. Base of the each pyramid faces cortex, while apex empties into cuplike cavities called Calycles.

Cortex and Nephron Is composed of millions of microscopic functional units called nephrons. Is composed of millions of microscopic functional units called nephrons. The nephron is the functional unit of the kidney. The nephron is the functional unit of the kidney. Its parts include: Its parts include: –Bowman’s capsule –Glomerulus- cluster of capillaries that Bowman’s capsule surrounds. –Proximal Convoluted tubule –Loop of Henle –Distal convoluted tubule –Collecting tubule

Urine Formation in the Nephron Filtration Filtration Re-absorption Re-absorption Secretion Secretion

Filtration First step in urine formation First step in urine formation Blood from renal artery enter glomerulus (which filters substances from the blood). Blood from renal artery enter glomerulus (which filters substances from the blood). High blood pressure in glomerulus forces fluid to filter into Bowman’s capsule (cup-shaped structure on the upper area of a nephron). High blood pressure in glomerulus forces fluid to filter into Bowman’s capsule (cup-shaped structure on the upper area of a nephron). Filtrate does not contain plasma proteins or RBCs- they are too big. Filtrate does not contain plasma proteins or RBCs- they are too big. Bowman’s capsule filters out 125cc of fluid/min cc/hr Bowman’s capsule filters out 125cc of fluid/min cc/hr As filtrate continues through nephron, 90% of water is reabsorbed. As filtrate continues through nephron, 90% of water is reabsorbed.

Re- Absorption A useful substance filter out of the renal tubules and back into the capillaries around the tubules. A useful substance filter out of the renal tubules and back into the capillaries around the tubules. Water and useful substances are reabsorbed. Water and useful substances are reabsorbed. If blood levels of certain substance are high (glucose, amino acids, vitamins, sodium) then these substances will not be reabsorbed. If blood levels of certain substance are high (glucose, amino acids, vitamins, sodium) then these substances will not be reabsorbed. Glucose is not normally secreted in the urine. Glucose is not normally secreted in the urine.

Secretion Opposite of reabsorption. Opposite of reabsorption. Secretion transports substances from blood into collecting tubules. Secretion transports substances from blood into collecting tubules. Substances include creatinine, hydrogen ions, potassium ions, and some drugs. Substances include creatinine, hydrogen ions, potassium ions, and some drugs. Electrolytes are selectively secreted to maintain body’s acid-base balance. Electrolytes are selectively secreted to maintain body’s acid-base balance.

Urinary Output Average= 1500ml/day Average= 1500ml/day Urinalysis- examination of urine to determine presence of blood cells, bacteria, acidity level, specific gravity and physical characteristics (color, clarity and odor) Urinalysis- examination of urine to determine presence of blood cells, bacteria, acidity level, specific gravity and physical characteristics (color, clarity and odor)

Ureters One from each kidney One from each kidney Carry urine from kidney to bladder Carry urine from kidney to bladder Smooth muscles tube with mucous membrane lining Smooth muscles tube with mucous membrane lining Peristalsis pushes urine down ureters. Peristalsis pushes urine down ureters.

Urinary Bladder Located in the pelvic cavity. Located in the pelvic cavity. Function is to store and aid the elimination of urine. Function is to store and aid the elimination of urine. Hollow, muscular organ Hollow, muscular organ Made of elastic fibers and involuntary muscle Made of elastic fibers and involuntary muscle Stores urine- usually about 500cc Stores urine- usually about 500cc Emptying urine (voiding) is involuntary but controlled through nervous system (voluntary) Emptying urine (voiding) is involuntary but controlled through nervous system (voluntary) Urine leaves through urethra to outside opening= urinary meatus. Urine leaves through urethra to outside opening= urinary meatus.

Control of Urinary Secretion ADH and aldosterone control the production of urine. ADH and aldosterone control the production of urine. Reabsorption of H20 is distal convoluted tubule controlled by ADH (antidiuretic horomone). Reabsorption of H20 is distal convoluted tubule controlled by ADH (antidiuretic horomone). Secretion and regulation of ADH controlled by hypothalamus. Secretion and regulation of ADH controlled by hypothalamus. Aldosterone is secreted by adrenal cortex, promotes excretion of potassium and hydrogen ions, reabsorption of sodium, chlroine ions and H20. Aldosterone is secreted by adrenal cortex, promotes excretion of potassium and hydrogen ions, reabsorption of sodium, chlroine ions and H20. Renin is a horomone released by kidneys, stimulates release of aldosterone from adrenal cortex. Renin is a horomone released by kidneys, stimulates release of aldosterone from adrenal cortex. Diuretics inhibit reabsorption of H20. Diuretics inhibit reabsorption of H20.

Nervous Control Direct control through nerve impulses on kidney blood vessels. Direct control through nerve impulses on kidney blood vessels. Indirect control through stimulation of endocrine glands. Indirect control through stimulation of endocrine glands.

Disorders of the Urinary System Acute Kidney Failure Acute Kidney Failure –Caused by nephritis, shock, injury, bleeding, sudden heart failure or poisoning. –Symptoms- early sign=oliguria (scant urine) or anuria (no urine produced). –Supression of urine formation can lead to uremia which is toxic condition when blood retains urinary waste products. Chronic Renal Failure Chronic Renal Failure –Gradual loss of function of nephrons.

Disorders of the Urinary System continued… Glomerulonephritis Glomerulonephritis –Inflammation of glomerulus –Filtration process affected –Plasma proteins are filtered through and found in urine, RBCs too (Hematuria). –Can be acute (caused by a bacteria) or chronic (when there is permanent damage). Hydronephrosis Hydronephrosis –Urine backs up because of blockage in ureter, renal pelvis and calyces become distended. –Can be due to kidney stones. –Can also be caused by pregnancy or enlarged prostate. –Treatment- remove the cause

Disorders of the Urinary System continued… Pylonephritis Pylonephritis –Inflammation of kidney tissue and renal pelvis –Usually caused by infection from ureters –One symptom is pyuria (pus in urine). –Treatment= antibiotics Renal Calculi (Kidney Stones) Renal Calculi (Kidney Stones) –Made of crystals of calcium phosphate and uric acid. –Gradually they get larger until they block ureters- obstruction –First symptom- severe pain, can cut living of the ureters or urethra. –Other symptoms include nausea and vomiting, frequency, chills, fever, and hematuria. –Diagnosis- by symptoms ultrasound, or x-ray –Rx= increase fluids to flush out stone, medications, and if needed- Lithotripsy

Disorders of the Urinary System continued… Lithotripsy Lithotripsy –Surgical procedure to remove kidney stones –Shock waves hit dense stones and break them up –Done on outpatient basis Cystitis Cystitis –Inflammation of the mucous membrane lining of the urinary bladder –Most common cause- E. Coli –Symptoms- dysuria (painful urination) and frequency –Usually found in females (shorter urethra) –Rx= antibiotics Incontinence- involuntary urination Incontinence- involuntary urination –Sometimes you would have to have a Foley catheter

Disorders of the Urinary System continued… Dialysis Dialysis –Used for kidney failure –Involves the passage of blood through device with semi-permeable membrane –Dialysis serves as substitute kidney Hemodialysis Hemodialysis –Used to treat kidney failure –Blood from patient flows through machine and is filtered. –Usually a fistula is created (opening b/w vein and artery) for inserting needles. –Can be done at home or in clinic. –Takes 2 to 4 hours, 2-3 times a week.

Disorders of the Urinary System continued… Peritoneal Dialysis Peritoneal Dialysis –Uses the peritoneal lining to filter blood. –Dialysate (cleaning solution) flows in and out via tube. Kidney Transplant Kidney Transplant –Possible treatment for renal failure –Is used for a last resort –Involves donor organ from someone with a similar immune system. –Main complication- rejection Enuresis- bedwetting Enuresis- bedwetting Glycosuria- sugar in urine Glycosuria- sugar in urine Nocturia- frequent urination at night Nocturia- frequent urination at night Polyuria- large amounts of urine. Polyuria- large amounts of urine.

The End!!!!!!