LEAD POISONING
la ta n o p ro s t
A
p r o s t a g l a n d i n d r u g
used as eye-drops
in the treatment of the eye condition
g l a u c o m a
(increased pressure of fluid
within the eyeball).
la te ra l
Relating to, or situated on, one side.
“Bilateral” means “ on both sides” .
la te ra l c u ta n e o u s n e rv e
e n tra p m e n t
Compression of the thigh’s lateral cuta-
neous nerve, w hich supplies the skin of
the front and outer areas of the thigh.
The nerve passes underneath the ingui-
nal ligament (the fibrous band of tissue
that extends across the crease of the
groin); if, for any reason, the ligament
puts pressure on the nerve the result is
a burning, tingling sensation and some-
times a condition known as
m e r a l g i a
p a r a e s t h e t i c a
(numbness in the thigh).
In many cases, the problem is due to
obesity. It may also result from over-
stretching of the hip joint, for example,
when playing sport, or wearing con-
stricting clothes around the hips.
There is no specific treatment. In
obese people, weight loss may help to
relieve the symptoms. Rarely, surgery is
performed to try to reduce the pressure
on the nerve.
la te x fix a tio n te st
Also called the latex agglutination test, a
procedure that is performed on body
fluids, such as urine, blood, and saliva,
in order to detect the presence of par-
ticular infections. Tiny beads of latex are
coated with
a n t i b o d i e s
(proteins pro-
duced by the immune system) against a
certain infectious organism and then
added to a sample of body fluid. If the
organism is present in the sample, it
reacts with the antibodies on the beads,
causing them to clump together.
la t is s im u s d o rs i
A large, flat, triangular
m u s c l e
in the
back. One end of the muscle is fixed to
the lower chest vertebrae and the back
of the
p e l v i s ,
while the other end of
the muscle is joined to the top of the
h u m e r u s
(upper arm bone). Contraction
of the latissimus dorsi muscle moves
the arm downwards and backwards.
la u d a n u m
A solution of
o p i u m ,
formerly used as a
sedative and painkiller and in the treat-
ment of diarrhoea.
la u g h in g g a s
The popular name for
n i t r o u s o x i d e ,
used
with oxygen in general
a n a e s t h e s i a .
L a u r e n c e -B ie d l- M o o n
s y n d ro m e
A rare inherited disorder characterized
by obesity,
r e t i n i t i s p i g m e n t o s a
(degener-
ation of the retina that may lead to
blindness),
l e a r n i n g d i f f i c u l t i e s , p o l y d a c t y l y
(extra digits), and
h y p o g o n a d i s m
(under-
activity of the ovaries or testes). (See
also
g e n e t i c d i s o r d e r s . )
la v a g e , g a s tric
Washing out the stomach with water,
usually to remove toxins. The person is
laid on one side, with the head lower
than the stomach. One end of a lub ri-
cated, flexible tube is passed down the
o e s o p h a g u s
(gullet) into the stomach.
The other end is attached to a funnel.
Water is poured into the tube until the
stomach is full, then the funnel end is
lowered, allowing the stomach contents
to drain into a bucket. The procedure is
repeated until the water runs clear.
Lavage is not used if a corrosive poi-
son has been swallowed because of the
risk that the tube may perforate tissues
in the oesophagus or stomach.
la x a tiv e d ru g s
COMMON DRUGS
bulk-forming
•Ispaghula •Methylcellulose
• Sterculia
stimulant
• Bisacodyl •Co-danthramer
• Co-danthrusate, • Docusate sodium •Senna
• Sodium picosulfate
lubricant
• Docusate sodium
• Liquid paraffin
o sm o tic
•Lactulose •Magnesium citrate
• Magnesium hydroxide •Magnesium
sulphate •Sodium acid phosphate
A group of drugs used to treat
c o n s t i -
p a t i o n
by making faeces pass through
the intestines more quickly and easily.
Laxatives are also given to people with
h a e m o r r h o i d s
(piles), to prevent strain-
ing during defecation. In addition, they
may be used to
clear the
intestine
before investigative procedures such as
c o l o n o s c o p y
or barium
e n e m a ,
or before
abdominal surgery.
TYPES
There are various types of laxative, all
of w hich work on the large intestine,
either by increasing the speed with
w hich faeces pass through the bowel, or
by increasing their bulk and/or water
content. Bulk-forming laxatives are not
absorbed as they pass through the di-
gestive tract. They contain particles that
absorb many times their own volume of
water, thereby increasing the volume
and softness of the faeces and making
them easier to pass. Stimulant laxatives
prompt the intestinal wall to contract
more strongly and speed up the elim i-
nation
of faeces.
Lubricant
laxatives
soften and facilitate the passage of fae-
ces. Osmotic laxatives cause water to be
retained in the intestine, thus increasing
the softness and volume of the faeces.
POSSIBLE ADVERSE EFFECTS
If they are used in excess, laxative drugs
may
cause
abdominal
cramps,
diar-
rhoea, flatulence, and disturbances in
body chemistry. Lubricants may prevent
the fat-soluble vitamins (A, D, E, and K)
from being absorbed in the intestine.
Prolonged use
of stimulant laxatives
may lead to dependence on them for
normal bowel function. For these rea-
sons, laxatives should be used only if
absolutely necessary, and for as little
time as possible. W hen taken to relieve
constipation, their use should be dis-
continued as soon as normal bowel
movements have resumed. If constipa-
tion lasts for more than a week,
a
doctor should be consulted.
la z y e y e
A term for the visual defect that common-
ly results from squint (see
a m b l y o p i a ) .
LDL
See
l o w d e n s i t y l i p o p r o t e i n .
le a d p o is o n in g
Damage to the
b r a i n , n e r v e s ,
red
b l o o d
c e l l s ,
and digestive system caused by
inhaling lead fumes or swallowing lead
salts. Acute poisoning, w hich occurs
when a large amount of lead is taken
into the body over a short period of
time, is sometimes fatal but is rare.
Chronic poisoning can be caused by
exhaust fumes from vehicles running
on leaded petrol, or by old paint or
water pipes containing lead.
SYMPTOMS AND SIGNS
Symptoms of acute poisoning include
severe, colicky abdominal pain, diar-
rhoea, and vomiting. There may also be
a n a e m i a
, appetite loss, and, in chronic
lead poisoning, a blue, grey, or black
line along the gum margins.
Chronic poisoning can have especi-
ally severe effects on children: it can
damage the brain and nervous system,
leading
to
behavioural and learning
L
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