CHRONIC OBSTRUCTIVE PULMONARY
CIRCULATORY SYSTEM
C
muscle fatigue, unrefreshing sleep, and
headaches. The syndrome is often asso-
ciated with
depression
or
anxiety
.
There is no specific diagnostic test for
chronic fatigue syndrome, and investi-
gations are usually aimed at excluding
other possible causes of the symptoms,
such as
anaemia
.
A physical examination,
blood tests, and psychological assess-
ment may be carried out. If no cause can
be found, diagnosis of chronic fatigue
syndrome is made from the symptoms.
Analgesic drugs
or
antidepressant drugs
may relieve the symptoms.
Physiotherapy
or
psychotherapy
may also be helpful.
Chronic fatigue syndrome is a long-
term disorder, but the symptoms clear
up after several years in some people.
chronic obstructive pulmonary dis-
ease
See
pulmonary disease, chronic
obstructive.
ciclosporin
An
immunosuppressant drug
used following
transplant surgery
. The
drug reduces the risk of tissue rejection
and the need for large doses of
cortico-
steroid drugs
.
Ciclosporin may need to
be taken indefinitely after a transplant. It
is also used to treat
rheumatoid arthritis
and other
autoimmune disorders.
Because
ciclosporin suppresses the
immune sys-
tem
,
it increases the susceptibility to
infection. Swelling of the gums and in-
creased hair growth are fairly common.
Ciclosporin may also cause kidney dam-
age, and regular monitoring of kidney
function is required.
cilia
Hair-like filaments on the surface
of some epithelial cells (see
epithelium
).
Cilia are found particularly in the linings
of the respiratory tract, where they pro-
pel dust and mucus out of the airways.
ciliary body
A structure in the
eye
con-
taining muscles that alter the shape of
the
lens
to adjust focus. (See also
accommodation
.)
cimetidine
An H
2
-receptor
antagonist
used as an
ulcer-healing drug
. Cimeti-
dine promotes the healing of gastric
and duodenal ulcers (see
peptic ulcer
)
and reduces the symptoms of
oeso-
phagiti
s. Side effects include dizziness,
fatigue, and rashes. More rarely, the drug
causes impotence and
gynaecomastia
.
CIN
The abbreviation for
cervical intra-
epithelial neoplasia
.
cinnarizine
An
antihistamine drug
used
to control nausea and vomiting due to
travel sickness or to reduce nausea and
vertigo in inner-ear disorders, such as
labyrinthitis
and
Meniere's disease
.
High
doses are sometimes used to improve
circulation in
peripheral vascular disease
and
Raynaud's disease
.
Side effects may
include drowsiness, lethargy, dry mouth,
and blurred vision.
ciprofloxacin
An
antibacterial drug
used
mainly to treat infections of the respira-
tory, gastrointestinal, and urinary tracts.
circadian rhythms
Any biological pat-
tern based on a cycle approximately 24
hours long, also called a diurnal rhythm.
(See also
biorhythms
.)
circulation, disorders of
Conditions af-
fecting blood flow around the body (see
arteries, disorders of; veins, disorders
of).
circulatory system
The
heart
and
blood
vessels
, which together maintain a con-
tinuous flow of blood throughout the
body. The system provides tissues with
oxygen and nutrients, and carries away
waste products. The circulatory system
consists of
2
main parts: the systemic
circulation, which supplies blood to the
whole body apart from the lungs; and the
pulmonary circulation to the lungs.
Within the systemic circulation, there is
a bypass (the portal circulation), which
carries nutrient-rich blood from the stom-
ach,
intestine,
and
other
digestive
organs to the liver for processing, stor-
age, or re-entry into general circulation.
In the systemic circulation, oxygen-rich
blood from the pulmonary circulation is
pumped under high pressure from the
left
ventricle
of the heart into the
aorta
,
from where it travels through arteries
and smaller arterioles to all parts of the
body. Within body tissues, the arterioles
branch into networks of fine blood ves-
sels called capillaries. Oxygen and other
nutrients pass from the blood through
the capillaries' thin walls into body tis-
sues; carbon dioxide and other wastes
pass in the opposite direction. Deoxy-
genated blood is returned to the heart
via venules, veins, and the
venae cavae
.
Venous blood returns to the right atri-
um of the heart to enter the pulmonary
circulation. It is pumped from the right
ventricle through the pulmonary artery
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