Urinary System Dr. Thorson
Lesson Objectives Upon completion of this lesson, students should be able to Define and spell the terms to learn for this chapter. Describe the purpose and function of the urinary system. Identify the structure and function of the individual organs of the urinary system.
Lesson Objectives List and discuss the three processes involved in the formation of urine. Explain the normal constituents of urine.
Structures of
Overview of Function Produce and excrete urine from the body To remove metabolic waste from blood Nephrons in kidneys filter blood to accomplish removal of wastes. Nephron in the kidney (more to come on nephrons later.)
Urine Is the waste product produced by the kidneys Contains mostly water as well as salts and nitrogen compounds Drains from the kidneys through the ureters to the bladder Is stored in the bladder Bladder empties during urination
Structure of the Kidneys Bean-shaped organs Located at the posterior region of the abdominal cavity between the 12th thoracic and 3rd lumbar vertebrae Encased in three capsules for protection True capsule Perirenal fat Renal fascia
External Structure of the Kidneys Hilum Entrance for renal arteries, nerves, and lymphatic vessels Renal Pelvis Collection point for urine before it is transported to the ureter
Internal Structure of the Kidneys Cortex Outer layer Contains arteries, veins, convoluted tubules, and glomerular capsules (part of the nephron) Medulla Inner layer Renal pyramids contain collecting tubules
The Nephron Functional unit of the kidney Each kidney contains more than one million nephrons
The Nephron Nephron consists of: Glomerulus Bowman s Capsule Renal tubule Proximal convoluted tubule Loop of Henle Distal convoluted tubule Collecting tubule
Ureters Two muscular tubes that carry urine from the kidneys down to the urinary bladder Composed of three layers Inner mucous membrane Middle layer of smooth muscle Outer fibrous layer About 28 34 cm (10 12 in.) long and less than 1 mm to 1 cm (¼ inch) in diameter
Consists of four layers Inner layer of epithelium Layer of smooth muscle Layer of longitudinal muscle Outer fibrous layer Stretches to hold urine The Urinary Bladder Urge to urinate typically occurs when the adult bladder holds 300 350 ml of urine Empties through the urethra and the urinary meatus
Urethra Musculomembranous tube extending from the bladder to the urinary meatus, the external opening of the urinary system In males, the urethra is approximately 20 cm long and transports both urine and semen The male urethra has three sections: Prostatic Membranous Penile
Female Urethra In females, the urethra is approximately 3 cm long and transports only urine Its external opening is situated between the clitoris and the opening of the vagina
Urine Filtration Process Filtration Blood pressure forces small molecules in the blood into the nephron through the pores in the walls of the glomerular capillaries and the Bowman s capsule
Urine Filtration Process Reabsorption As the filtrate passes through the tubules, water and dissolved materials are reabsorbed by the blood Secretion Other substances (waste) are transported into the filtrate to become urine
Facts About Urine Consists of water, hydrogen ions, and uric acid Adult passes about 1,000 1,500 ml of urine daily Characteristics of normal urine Clear versus cloudy Straw colored Specific gravity of 1.003 1.030 Slightly acidic ph of about 6 Specifications of normal urine vary with age
Cystitis Inflammation of the bladder Occurs when bacteria infect lower urinary tract causing irritation and inflammation
Cystitis Common disorder Can affect anyone; particularly sexually active women ages 20 50 due to anatomical configuration In men, usually secondary to another infection
Cystitis Urgency (need to void immediately) Frequency (need to void often) Itching Painful urination Dark, cloudy, blood tinged urine May have foul odor Chills and fever
Cystitis Treatment Antibiotics Medications to relieve sense of burning pain or urgency Increasing fluid intake
Glomerulonephritis Also called glomerular disease Inflammation of kidneys that primarily affects the glomeruli Hinders kidneys' ability to properly filter waste and fluids from the blood Can be acute or chronic Can be part of systemic disease or a disease by itself
Glomerulonephritis Causes Infections Autoimmune diseases Inflammation of blood vessels (vasculitis) Conditions that scar glomeruli Develops after bout of acute glomerulonephritis
Glomerulonephritis Abnormal urinalysis Urine dark amber color or blood in urine Foam in toilet water caused by protein in urine High blood pressure
Glomerulonephritis Fatigue Joint and muscle aches Edema Abdominal pain Diarrhea
Glomerulonephritis Treatment varies based on underlying cause Medications to lower blood pressure Corticosteroids Limit sodium, fluid, protein intake
Incontinence Involuntary and unpredictable flow of urine Common in women who have had children
Incontinence Types Stress Overactive bladder Urge Overflow Incontinence while sleeping (enuresis) Transient
Incontinence Diagnosed by urologist or family physician Medications that relax bladder wall and reduce overactive contractions Surgery Kegel exercises (strengthen pelvic floor)
Critical Thinking Question 1.How can you show respect and sensitivity when discussing incontinence with a patient?
Kidney Stones Also called renal calculi Formed when urine contains too much of a certain substance (calcium, uric acid, phosphate, oxalate) Most stones formed by combination of calcium and oxalate Formed while still in kidney, but when they pass into ureter, they slow or block urine flow
Types of kidney stones found in an adult.
Kidney Stones Stones have rough surface and irritate and scratch ureters causing bleeding and intense physical pain To prevent stone formation, fluid intake should produce at least 2 quarts or at least 1,800 to 2,000 ml of urine each day
Kidney Stones Intense lower back (flank) pain Possible nausea and vomiting Decreased urine output Hematuria usually present
Kidney Stones Many pass out of body without intervention by a physician Lithotripsy Passing shock waves through body to break down physical structure of stone
Polycystic Kidney Disease (PKD) Multiple (poly) clusters of cysts develop primarily within and on surface of kidneys Associated with other disorders including aortic and brain aneurysms and diverticulosis
Polycystic Kidney Disease (PKD) Affects more than 12 million people worldwide Considered inherited disease Kidney failure common with PKD
Polycystic Kidney Disease (PKD) High blood pressure Back or side pain related to enlarged kidneys Abdominal pain particularly over liver Joint pain Drowsiness
Polycystic Kidney Disease (PKD) Increase in size of abdomen Blood in urine Kidney failure Kidney infections Headache
Polycystic Kidney Disease (PKD) Treatment Symptom control Minimizing complications of high blood pressure, pain, bladder and kidney infections, blood in urine, kidney failure
Pyelonephritis Urinary tract infection of kidney and renal pelvis Sudden onset or chronic condition
Pyelonephritis Causes: Bacteria and viruses Indwelling urinary catheter Cystoscopy Prostate enlargement Kidney stones
Pyelonephritis Back, side, groin pain Urinary urgency and frequency Pain and burning during urination Fever and chills Nausea and vomiting Blood in urine Treatment: antibiotics
Renal Failure Kidney ceases to function properly Inhibits filtration of blood Results in increased buildup of toxins and waste products May be acute or chronic
Acute Renal Failure Change in filtering function of kidneys, impairing kidneys' ability to maintain normal body function Can occur in matter of hours or over course of a couple of days Caused by blockage, toxins, sudden loss or decrease of blood flow to kidneys
Acute Renal Failure No immediate signs Urine output decreased Irregular heart rate Ascites
Acute Renal Failure Swelling in extremities Treatment: dialysis uses a filter other than the kidneys to remove toxins and maintain water balance Two types: hemodialysis and peritoneal
Dialysis machine showing diffusion of concentrations, which are the same, between the patient s blood and the dialysis solution.
Critical Thinking Question 1.What impact can dialysis have on a patient's lifestyle?
Chronic Renal Failure Gradual and progressive loss of kidney function that transpires over months to years Final stages referred to as end-stage renal disease (ESRD) Diabetes and hypertension two most common causes of chronic renal failure in U.S.
Chronic Renal Failure Fatigue Headaches Itchy and dry skin; changes in skin color Nausea Weight loss
Chronic Renal Failure Bone and nervous system changes Bone pain Excessive thirst Frequent hiccups Low levels of sexual desire and impotence
Chronic Renal Failure Treatment Identify, treat, reverse what is causing kidneys to fail Prevent excess fluid volume while kidneys heal and resume normal function If normal function cannot be regained, dialysis may be necessary
Hemodialysis Machine filters and cleans blood outside body Patients go to dialysis center three times a week for two to three hours treatments
Peritoneal dialysis Done through tissues of abdomen Patients dialyzed at home or any environment
Peritoneal dialysis.
Kidney Transplant Dialysis would continue until patient is able to receive a new kidney or for remainder of patient's life Kidney transplant recipients must take antirejection drugs for the rest of their lives to live with the transplanted kidney