THE URINARY SYSTEM
The urinary or excretory system functions to control the
volume and composition of the blood. It filters waste products
from the blood and expels them from the body in the form of
urine.
The Kidneys
The kidneys are two bean shaped organs found just above the waist on either side of
the vertebral column. Blood passes through the kidneys and waste products and
excess fluid is taken from it. The cleaned blood then returns to the circulatory
system.
Two kidneys are situated retroperitoneal on either side of the lumbar region of the
spine. They consist of a cortex region and an inner medulla. The depression on the
medial border is called the hilum through which blood vessels and nerves pass.
The functions of the kidneys are:
removal of urea from blood

maintenance of correct balance of water, salts and acids in body fluids, e.g.
salts such as sodium and potassium. Some acids are known as electrolytes.
Electrolytes are necessary for correct functioning of muscles and nerve cells.
The kidneys form urine and eliminate it from the body. The endocrine function
of the kidneys is to secrete renin a substance important in the control of blood
pressure, erythropoietin, a hormone that regulates production of erythrocytes
(red blood cells) and an active form of Vitamin D (which aids in the absorption
of calcium) from the intestines.
Nephrons are the filtration units of the kidney. Each nephron contains a cluster of
blood capillaries called glomeruli (singular is glomerulus). This is where the blood is
actually filtered.
The renal cortex is the rind or outer area of the kidney, the middle is called renal
medulla and the inner section is called the renal pelvis. The renal pelvis is the central
collecting region of the kidney at the wide upper end of the ureter.
Ureters
Once urine is filtered through the nephrons, it drains into the renal pelvis. From the
renal pelvis, urine is transported away from the kidneys in tubes called ureters. The
ureters join the urinary bladder. There are two (2) ureters which are muscular tubes,
lined with mucous membrane. Their function is to convey urine from the kidneys to
the urinary bladder.
Urinary Bladder
The urinary bladder is a hollow muscular sac, which serves as a temporary reservoir
for urine. At its base is a triangular space the trigone, where the ureters enter and
the urethra leads out. When urine is expelled from the bladder it is called micturition,
voiding or urination. The bladder can also be referred to as a vesicle.
URINARY SYSTEM
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Urethra
The urethra is a small tube through which urine is moved from the bladder to the
exterior of the body. The female urethra is about 4cm long while the male urethra is
about 20cm long. The urinary meatus is the term given to the external opening of the
urethra.
Urine
Urine is composed of 95% water; the rest is made up of waste products.
Word
Parts
Albin
AlbumAlbumin
Azot
Cyst
-Gram
Hydr/o
Lith
Combining form
Meaning
Albin/o
White
White
Albumin (protein)
Urea
Bladder (sac)
X-ray, image, tracing, recording
Water
Stone
Kidney (nephron- functioning part of the kidney. Basic
unit of kidney, comprising a glomerulus, Bowmans's
capsule etc.
Deficiency/few/little
Many/much
Falling/displacement
Refers to the space inside the kidney, renal pelvis (pyle portal vein)
Kidney
Trigone of the bladder
Urine
Urinary canal, ureter (kidney to bladder)
Tube through which urine leaves the body from the
bladder, urethra (bladder to outside)
Urine, the excretory or waste product of the kidneys
Bladder (or sac/blister)
Albumin/o
Azot/l
Cyst/o
Hydr/o
Lith/o
Nephr
Nephr/o
Olig/o
Poly-ptosis
Olig/o
Pyel
Pyel/o
Ren
Trigon
Ur
Ureter
Ren/o
Trigon/o
Ur/o, -uria
Ureter/o
Urethr
Urethr/o
Urin
Vesic
Urin/a, urin/o, urin/i
Vesic/o
Activity 1
Write the meaning of the following words:
1. renogram
2. nephrolithotomy
3. glomerulitis
4. pyelonephrosis
URINARY SYSTEM
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5. vesicocele
6. urethrostenosis
7. urinalysis
8. oliguria
9. dysuria
10. lithotripsy
Activity 2
Build words which mean:
1. Surgical fixation of a kidney
2. Condition of pain in a kidney
3. Surgical repair of the renal pelvis
4. x-ray picture of the renal pelvis
5. Instrument to view the bladder
6. Specialist who studies the urinary tract
7. Abnormal urination at night
Diseases and disorders of the urinary system
The urinary system has two major types of disorders that affect it. One is when the
filtration of urine from the blood is disturbed, the other is when the flow of urine either
from the kidneys to the bladder, or from the bladder to the outside of the body, becomes
blocked.
If the filtration of blood does not take place, then the blood quickly becomes toxic. If the
patient is not treated they will die. This condition is commonly known as renal failure.
Interventions to save the patient can be artificial filtration of the blood by a process
called dialysis; another approach may be a kidney transplant. Renal failure is caused
by damage to the kidneys, which can include infections, trauma, cancer, or damage
caused by toxic (poisonous) agents, such as certain drugs.
Blockages in the ureters, bladder and urethra can be caused by inflammation from
infections, cancers and tumours, and mineral deposits that form stones or calculi –
these are known as kidney stones or renal calculi, and sometimes they have to be
surgically removed. If a blockage occurs in the renal tract then the urine begins to build
up. If the blockage is not removed, the urine will quickly backup into the kidneys and
cause damage.
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Other disorders involve the composition of urine, the amount of urine that is passed
from the body, and the ability of the body to control the bladder.
Diseases and disorders include:
Disease
Albuminuria
Definition
Presence of protein (albumin) in the urine
Anuria
Cystitis (cyst/o means
bladder)
Dysuria
An inability to pass urine, or an absence of urine
Enuresis
Incontinence at night, bed wetting
Frequency
Passing of urine more than every two hours
Haematuria
Blood in the urine
Incontinence
Involuntary passing of urine
Nephritis
Inflammation of the kidney
Nephrolithiasis
Stones in the kidneys (calculi) (abnormal condition of)
Nocturia
Abnormal urination during the night
Polyuria
Pyelonephritis
Passing large amounts of urine, of frequent urination
Presence of above normal levels of protein in the urine,
usually indicating a urinary tract infection
Inflammation of the kidney caused by bacterial infection
Renal calculi
A stone in the urinary tract
Retention
Inability to pass urine
Urethritis
Inflammation of the urethra
Urinalysis
A test to analyse the composition of the urine
Urinary alkaliniser
A medication to reduce acid content of urine (e.g. Ural)
A general term meaning an infection in the ureters, bladder
and/or urethra
Proteinuria
Urinary Tract Infection (UTI)
URINARY SYSTEM
Inflammation of the bladder
Painful or difficult urination
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Activity 3
Read the following paragraph and rewrite it using lay terms.
A 26 year old woman presented with a two day history of severe dysuria. She has
been passing small amounts of urine with increasing frequency. A urinalysis was
performed with the results showing moderate proteinuria and haematuria. There was
no indication of nephritis or kidney involvement on physical examination, and a
diagnosis of cystitis was made. The patient was prescribed a urinary alkaliniser and
antibiotics.
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Abbreviations:
ARF
BUN
CRF
CSU
HD
HNPU
IVP
KUB
MSU
TUR (TURP)
UA, Ua
UTI
Acute renal failure
Blood, urea, nitrogen
Chronic renal failure
Catheter specimen urine
Haemodialysis
Has not passed urine
Intravenous pyelogram
Kidneys, ureters, bladder
Mid stream urine
Transurethral resection (of the prostate)
urine analysis (urinalysis)
Urinary tract infection
Procedures:
Haemodialysis
Pyelogram
(intravenous)
Pyelogram
(antegrade)
Pyelogram
(retrograde or
ascending)
URINARY SYSTEM
Technique of removing waste materials or poisons from the blood using the
principle of dialysis
Injection of contrast medium via vein into blood stream which then runs
through kidneys and x-ray is taken (intra – meaning inside, ven/o – meaning
vein)
The dye is injected into the renal pelvis before it leaves the kidney. (ante –
meaning before/in front; grad – meaning take steps/to go). The dye is
injected through the skin via a percutaneous catheter.
Insertion of cystoscope into bladder, fine tube passed through cystoscope
up ureter to kidney, contrast medium injected into the urine within the
pelvis, x-ray taken (against the flow) (retro – latin, means backwards)
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Urinary system
Write the combining forms on the dotted lines using the following word
components. More than one component may relate to the one position.
Cyst/o
Glomerul/o
Nephr/o
Pyel/o
Ureter/o
Urethr/o
Urin/o
Vesic/o
URINARY SYSTEM
Ren/o
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