URINARY SYSTEM
URINARY TRACT INFECTION
URINARY TRACT
Ureter
Urethra
Aorta
Kidney
(whole)
Renal
artery
Prostate
gland
Urethra
MALE
Adrenal gland
(cross section)
Kidney (cross section)
Renal vein
Ureter
Peritoneum folded back
Bladder
Bladder
FEMALE
stone in the bladder (see
calculus, urin-
ary tract),
and enlargement or tumour
of the prostate (see
prostate, enlarged;
prostate, cancer of
). In females, causes
include pressure on the urethra from
uterine
fibroids
or from a
fetus
. In either
sex, the cause may be a bladder tumour.
Retention may also be due to defective
functioning of the nerve pathways sup-
plying the bladder as a result of general
or spinal
anaesthesia
, drugs affecting
the bladder, surgery, injury to the nerve
pathways, or disease of the spinal cord.
Complete retention causes discomfort
and lower abdominal pain, except when
nerve pathways are defective. The full
bladder can be felt above the pubic bone.
However, chronic or partial retention
may not cause any serious symptoms.
Retention can lead to kidney damage
and, often, a urinary tract infection.
Treatment of retention is by catheteri-
zation (see
catheterization, urinary
). The
cause is then investigated. Obstruction
can usually be treated; if nerve damage
is the cause, permanent or intermittent
catheterization is sometimes necessary.
urinary system See
urinary tract.
urinary tract The part of the body con-
cerned with the formation and excretion
of
urine.
The urinary tract consists of
the
kidneys
(with their blood and nerve
supplies), the renal pelvises (funnel-
shaped ducts that channel urine from
the kidneys), the
ureters
, the
bladder
,
and the
urethra.
The kidneys make urine by filtering
blood. The urine collects in the renal
pelvises and is then passed down the
ureters into the bladder by the actions
of gravity and
peristalsis
. Urine is stored
in the bladder until there is a sufficient
amount present to stimulate
micturi-
tion.
When the bladder contracts, the
urine is expelled through the urethra.
urinary tract infection An infection
anywhere in the
urinary tract.
It has
differing symptoms, depending on the
area affected.
Urethritis
causes a burn-
ing sensation when urine is being
passed.
Cystitis
causes a frequent urge
to pass urine, lower abdominal pain,
haematuria,
and, often, general malaise
with a mild fever.
Pyelonephritis
causes
fever and pain in the back under the
ribs. Cystitis and pyelonephritis are
U
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