Page 355 - Biology_F5

Biology for Advanced Level Secondary Schools

failure to produce enough erythropoietin vagina, sexually transmitted infections
for adequate red blood cells production, such as herpes, gonorrhea, chlamydia and
hence anaemia. mycoplasma can cause urethritis.

Kidney stones (renal calculi) The infection of the urinary tract can
Concentration of mineral and organic result into either minor or major illnesses.
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matter that forms in the kidneys results For example, an attack of cystitis-
into small particles called stones. These inflammation of the bladder may cause
may become too large, hence impairing only minor illness. The attack of the renal
the normal renal function. Urine contains system is characterised by frequent and
many salts in solution. If the concentration painful urination. Other complications
of these mineral salts becomes excessive, include recurrent infections; especially
excess salts precipitate as crystals that may in women who experience twice or more
enlarge to become visible solid particles UTI cases in a six-month period within a
called stones. Such stones give rise to year and permanent kidney damage from
severe colic pain starting in the back and twice acute or chronic kidney infection
radiating down to the front of the thigh or (pyelonephritis) due to an untreated UTI.
the testicle or vulva on that side. The best Likewise, pregnant women get a risk of
way to prevent most kidney stones is to delivering low birth weight or premature
drink enough water every day. infants, whereas men experience urethral
narrowing (stricture).
Urinary tract infections (UTI)
In humans, UTI is caused by the invasion The preventive measures include: drinking
of microorganisms, usually bacteria, plenty of liquids especially water so as to
into the urethra and bladder. The most dilute urine and ensure frequent urination
common UTI cases that affect the bladder hence, allowing bacteria to be flushed from
and urethra are: the urinary tract. Also, women are advised
to wipe from front to back after urinating
Infection of the bladder (cystitis): This and after defaecating so as to prevent the
type of UTI is usually caused by bacteria, spread of bacteria from anal region to
normally Escherichia coli (E. coli); a the vagina and urethra. Furthermore, a
type of bacteria commonly found in the patient should seek medical advice from a
gastrointestinal tract (GIT). All women recognised health centre or hospital.
are at risk of cystitis because of their
anatomy, specifically the short distance Urinary tract obstruction
from the urethra to the anus and the This is due to blockage or constriction at
urethral opening to the bladder. any point in the urinary tract. This impedes
the normal flow of urine and causes urine
Infection of the urethra (urethritis): This to be retained in the bladder or kidneys.
type of UTI can occur when GIT bacteria Obstruction causes urine to become
spread from the anus to the urethra. Also, blocked up into the kidneys, the condition
because the female urethra is close to the is known as hydronephrosis. Obstructions

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