Urinary Tract

Urinary Tract
Chapter 27
Microbiology for Surgical Technologists
Anatomy of the Urinary Tract
It is divided into the upper and lower tracts
The upper tract is composed of the kidneys and ureters
The lower tract is composed of the bladder and urethra
The kidney is surrounded by three layers of tissue
The outermost layer is the renal fascia
The middle layer is called the adipose capsule
What is adipose tissue?
The inner layer is the renal capsule
The inside of the kidney reveals the cortex and the inner medulla
Within the medulla are small triangular structures called renal pyramids
Together the renal cortex and pyramids make up the parenchyma of the kidney
What does parenchyma mean?
The parenchyma of the kidney is made up of one million collecting tubules called nephrons
The minor calyx is a funnel shaped structure that surround the tip of each pyramid and collects urine
The minor calyx joins the major calyx, which in turn join the renal pelvis
The urine then exits the kidney through the ureter
The ureter uses peristalsis to move the urine into the bladder
The bladder is a muscular hollow organ designed to hold urine
There are three openings, two for the ureters and one for the urethra
The trigone is a smooth triangular area that surrounds these openings
The urethra is a tube that begins at the base of the bladder and transports the urine to the outside
In the male it is approx 20 cm long, passes through the prostate gland just as it exits the bladder, then enters the penis
In females it is approx 3.8 cm long and is located posterior to the symphysis pubis,between the clitoris and the vaginal opening
Urine is sterile in the kidney, ureter, and bladder
It picks up resident flora in the urethra, most infections come from the urethra
Healthy urinary tracts resist infection because of the constant movement of fluid and a pH level that is not suitable for most bacteria
UTIs affect females far more than males
Why?
About one half of all females will have a UTI in their life
E. coli is the most common pathogen causing ascending UTI
What does this mean?
Very few viruses or parasites cause UTIs
UTIs are diagnosed as either upper or lower depending on the structure or organ affected
Upper UTI includes ureter infections (ureteritis) or kidney infections (pyelonephritis)
Lower UTIs include urethral infections (urethritis) or bladder infections (cystitis)
Acute lower UTIs can cause dysuria, urgency, and urgency
What do these terms mean?
The urine is typically clear and the color of wheat.
Cloudy urine is caused due to the presence of pus and bacteria
Cystitis
Acquired from ascending UTIs
Is rare in males, but when it occurs, usually involves the prostate
Usually caused by E.coli, which can thrive in urine
Urinary catheterization is a major cause of UTI because flora is picked up on the catheter and deposited in the bladder
Cystitis
(continued)
Can cause hematuria
Which can be associated with bacterial endocarditis, renal trauma, stones or urinary carcinomas
White blood cells are normal in the urine, but in great numbers may indicate neoplasms (tumors) or calculi (stones) in addition to UTIs
Pyelonephritis
A kidney infection resulting from cystitis
The infection can make its way into the blood steam and cause septicemia
Symptoms include: back pain, fever, and lower UTI symptoms
It can be life threatening and is treated aggressively with broad-spectrum antibiotics
Surgical Implication
STs often insert urinary catheters in the OR and need to maintain proper sterile technique
Recurrent pyelonephritis can damage the kidneys and require a nephrectomy
Calculi may require cystoscopy, ureteroscopy or lithotripsy to remove them
Surgical Implication
(continued)
Recurrent urethritis may cause constrictions that require dilation or a urethrotomy
Occurs most often in men
Chronic infections of the prostate can cause urethral constrictions and require a transurethral resection of the prostate (TURP)
Otis Urethrotome
There is no such thing as a great talent without great will power.
Honore De Balzac
(1799 – 1850)