I
BENEFITS OF FITNESS
W hen the body is fit, the maximum
work capacity and endurance are in -
creased. A
fit
person
has
a
better
chance of avoiding
coronary artery dis-
ease
as w ell as of preventing the effects
of aging and chronic disease.
The strength, endurance, and effi-
ciency of the heart is also increased by
exercise. A fit heart pumps 25 per cent
more blood per minute when at rest,
and over 50 per cent more blood per
minute during physical exertion, than
an unfit heart. A fit person’s heart nor-
mally beats 60 or 70 times a minute;
an unfit person’s heart beats 80 to
1 0 0
times per minute.
fitness testing
A series of exercises designed to deter-
mine an individual’s level of
fitness
,
prim arily his or her cardiovascular fit-
ness and muscle performance. Fitness
testing is often carried out before a
person starts an exercise programme to
evaluate its safety and suitability or to
monitor progress thereafter.
A physical examination is usually
performed, including measurement of
body fat, height, and weight. Blood
and urine tests may be done, including
an analysis of blood
cholesterol
.
The
performance of the heart is measured
by taking the pulse before,
during,
and
after
aerobic
exercise
such
as
step clim bing, riding a stationary bicy-
cle, or running on a treadmill. The
more efficient the heart, the slower it
works during exercise and the quicker
it returns to normal afterwards.
Another test involves measuring a
person’s overall performance in a stan-
dard exercise. This is most suitable for
m onitoring progress through an exer-
cise programme and for setting goals.
The test may be based either on mea-
suring the distance covered in a fixed
time or the time needed to cover a fixed
distance. (See also
aerobics
;
exercise
. )
fixation
In
psychoanalytic theory
,
the process by
w hich an individual becomes, or re-
mains, emotionally attached to real or
imagined objects or events that oc-
curred during early childhood. If the
fixations are powerful, resulting from
traumatic
events,
they may lead to
immature
and
inappropriate
behav-
iour.
Regression
to
these
events
is
regarded by some analysts as the basis
of certain emotional disorders.
FLATUS
The word “fixation” also describes the
alignment and stabilization
of frac-
tured bones. Fixation may be external,
as with a plaster
cast
,
or internal, using
pins, plates, or nails introduced surgi-
cally into the injured area.
fixative
A chemical agent, such as
formaldehyde
,
that is used for the hardening and pre-
servation of tissue specimens prior to
m icroscopic analysis (see
histology
) .
fixed pupil
An abnormal
pupil
(the circular opening
in the centre of the
iris
) that does not
react to light or adjust on
accommoda-
tion
(the process by w hich the eye
focuses on objects). A fixed pupil may
be symptomatic of various eye disor-
ders (see
eye, disorders of
) ,
such as acute
glaucoma
and
uveitis
,
or, rarely, of a
brain
tumour
in w hich
brainstem
structures
that control eye reflexes are compres-
sed. Both pupils being fixed and dilated
is a sign of brain death.
fixed-rate pacemaker
An
artificial
cardiac
pacemaker
(a
device that sends electrical impulses to
the
heart
to maintain a regular
heart-
beat
)
that is set to pace at a single rate
regardless of the patient’s own
heart
rate
.
Fixed-rate
pacemakers
are
still
used in some clinical and diagnostic
settings, and may be appropriate for
the elderly.
For active people,
rate-
responsive
pacemakers
(see
demand
pacemaker
) are often a better choice;
these devices deliver electrical stimuli
as required and at a rate to match the
patient’s level of activity.
flaccid
Lacking in firmness or characterized
by a loss of
muscle
tone.
flail chest
A type of chest injury that usually
results from a traffic accident or from
violence. In flail chest, several adjacent
ribs are broken in more than
one
place, producing a piece of chest wall
that moves in the opposite way to nor-
mal as the victim breathes: when the
victim
inhales,
and
the
rib
cage
expands,
the
flail
segment
moves
inwards,
and
during
exhalation
it
moves outwards.
The injury may severely im pair the
efficiency of breathing and may lead to
respiratory failure
and
shock
.
It makes
breathing and coughing very painful,
which can increase the risk of chest infec-
tion and lung collapse (see
atelectasis).
Emergency treatment involves turn-
ing the person on to the affected side
or firm ly strapping the flail segment.
In severe cases, artificial
ventilation
is
needed until the chest w all has become
stable and the ribs have healed.
flat-feet
A condition, usually affecting both feet,
in w hich the arch o f the foot is absent
and the sole rests flat on the ground.
The rches normally form gradually as the
supportive ligaments and muscles in
the soles develop; they are not usually
fully formed until about the age of six.
In some people, however, the ligaments
are lax, or the muscles in the feet are
weak, and the feet therefore remain flat.
Less commonly, the arches of the feet
may not form because o f a hereditary
defect in bone structure.
Flat-feet can be acquired in adult life
because o f fallen arches, sometimes as
the result of a rapid increase in weight.
Weakening of the supporting muscles
and ligaments of the feet may occur in
certain neurological or muscular dis-
eases, such as
poliomyelitis.
In most cases, flat-feet are painless
and require no treatment, although in
some cases the feet may ache on walk-
ing or standing. Arch supports can be
w orn in the shoes for comfort and
special exercises can be used to help
strengthen
weakened
ligaments
and
muscles. A small number o f affected
children require an operation to cor-
rect the bones in the feet.
flatulence
Abdominal discomfort or fullness that
is relieved by belching or by passing
w ind through the anus. Flatulence is a
feature o f many gastrointestinal condi-
tions, such as
irritable bowel syndrome
and
gallbladder
disorders.
W hen an individual is in an upright
position, most swallowed air passes
back up the
oesophagus
to be expelled
through the mouth. W hen a person is
in a prone position, the air may pass
through the intestine and anus instead.
Gas formed in the intestine is passed
only through the anus.
flatus
Gas, commonly known as “w in d ” , that
is passed via the anus. Gas is formed
in the large intestine by the action of
F
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