VENTOUSE
VERTEBRA
V
between the air in the lungs and the
blood. Ventilatory failure may be due to
brain damage or to depression of the
respiratory centres by excessive doses of
drugs such as
morphine.
Treatment may
involve artificial
ventilation
or, in some
cases, the use of respiratory stimulant
drugs. (See also
respiratory failure.)
ventouse See
vacuum extraction.
ventral Relating to the front of the
body, or describing the lowermost part
of a body structure when a person is
lying face-down. The opposite is
dorsal.
ventricle A cavity or chamber. Both the
heart
and
brain
have anatomical parts
known as ventricles.
The brain has 4 ventricles: 1 in each of
the 2 cerebral hemispheres; a 3rd at the
centre of the brain, above the brain-
stem; and a 4th between the brainstem
and cerebellum. These cavities are filled
with
cerebrospinal fluid
.
The ventricles of the heart are its 2
lower chambers, which receive blood
from each
atrium
and pump it to the
lungs and to the rest of the body.
ventricular ectopic beat A type of
cardiac
arrhythmia
in which abnormal
heartbeats are initiated from electrical
impulses in the
ventricles
of the
heart
.
In a normal heart, beats are initiated by
the
sinoatrial node
in the right atrium.
Ventricular ectopic beats may be de-
tected on an
ECG
. If there are frequent
abnormal beats that cause symptoms,
or beats that arise from more than
1
site in the ventricles, treatment with an
antiarrhythmic drug
may be required.
ventricular fibrillation One of the 2
life-threatening cardiac
arrhythmias
that
occur in
cardiac arrest
. The
heart
has
rapid, uncoordinated, ineffective con-
tractions and does not pump blood. The
problem is due to abnormal heartbeats
initiated by electrical activity in the
ven-
tricles
. It is a common complication of
myocardial infarction
and may also be
caused by electrocution or drowning.
The diagnosis is confirmed by
ECG
.
Emergency treatment is with
defibrilla-
tion
and
antiarrhythmic drugs.
ventricular septal defect The medical
term meaning a hole between the lower
2 chambers of the heart. The abnormality
is present from birth and in many cases
VENTRICULAR SEPTAL DEFECT
Ventricular septal
defect
Left
ventricle
of heart
Right
ventricle
of heart
Septum
is small and closes without treatment.
Surgery may be performed for larger
defects, usually with good results.
ventricular tachycardia A serious car-
diac
arrhythmia
in which each heartbeat
is initiated from electrical activity in the
ventricles
rather than from the
sinoatrial
node
in the right atrium. It is caused by
an abnormally fast heart-rate due to
serious heart disease, such as
myocar-
dial infarction
or
cardiomyopathy
. It may
last for a few seconds or for several
days. Diagnosis is confirmed by
ECG.
Emergency treatment is with
defibril-
lation
and an
antiarrhythmic drug
.
verapamil A drug that acts as a
calcium
channel blocker
to treat
hypertension
,
angina pectoris,
and certain
arrhythmias.
Possible side effects include headache,
flushing, dizziness, and ankle swelling.
vernix The white, cheese-like substance
covering a newborn baby. Vernix com-
prises fatty secretions and dead cells. It
protects the skin, insulates against heat
loss before birth, and lubricates the
baby's passage down the birth canal.
verruca The Latin name for a
wart,
com-
monly applied to warts on the soles.
version A change in the direction in
which a
fetus
lies so that a
malpresenta-
tion,
most often a breech (bottom-down)
presentation, replaces the normal head-
down presentation.
vertebra Any of the 33 approximately
cylindrical bones that form the
spine.
There are 7 vertebrae in the cervical
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