Bma Illustrated Medical Dictionary

oestrogen hormonesand androgen hor-
mones. Synthetic LH-RH, also known as
synthetic gonadorelin, is used to treat
delayed puberty, and to treat infertility
in women. LH-RH may cause headache,
nausea, hot flushes, vaginal dryness, and
irregular periods.
Lyme diseaseA disease caused by the
bacterium BORRELIA BURGDORFERI, which
is transmitted by the bite of a tick that
usually lives on deer. At the site of the
bite, a red dot may appear and gradually
expand into an area up to 5 mm (^1 / 4 in)
across. Symptoms including fever, head-
ache, and muscle pain usually develop;
these symptoms are followed by joint
inflammation, which typically affects the
knees and other large joints.
Symptoms may vary in severity and
occur in cycles lasting a week or so. If
the disease is not treated, complications
including meningitis, facial palsy, and an
abnormal heartbeat (see arrhythmia,
cardiac) may develop. The most serious
long-term complication is arthritis.The
disease can be cleared up with antibiotic
drugs. Treatment is most effective when
given soon after the initial infection.
lymphA watery or milky body fluid con-
taining lymphocytes, proteins, and fats.
Lymph accumulates outside the blood
vessels in the intercellular spaces of body
tissues, and is collected by the vessels of
the lymphatic system. This system filters
the fluid and eventually returns it to the
bloodstream. Lymph plays an important
role in the immune systemas well as in
absorbing fats from the intestine.
lymphadenitisA medical term for in-
flammation of the lymph nodes, which
is a common cause of lymphadenopa-
thy(see glands, swollen).
lymphadenopathyThe medical term for
swollen lymph nodes(see glands, swollen).
lymphangiographyA diagnostic pro-
cedure that involves injecting a contrast
mediuminto lymph vessels (see lym-
phatic system) so that these vessels and
lymph nodes, and any abnormalities,
can be seen on X-rayfilm. Lymphan-
giography has largely been superseded
by CT scanningand MRI.
lymphangiomaA rare, noncancerous
tumour of the skin or tongue consisting
of a mass of abnormal lymph vessels.

lymphangitisInflammation of the lym-

phatic vessels (see lymphatic system)

due to the spread of bacteria(commonly

streptococci) from an infected wound.

The inflammation causes tender red

streaks to appear on the skin overlying

the lymphatic vessels. These red streaks

extend from the infection site towards

the nearest lymph nodes. The affected

nodes become swollen and tender, and

there is usually fever and a general feel-

ing of illness. Lymphangitis requires

urgent treatment with antibiotic drugs.

lymphatic systemA system of vessels

(lymphatic vessels) that drains lymph

from tissues all over the body back into

the bloodstream. The lymphatic system

is part of the immune system and has a

major function in defending the body

against infection and cancer. This sys-

tem also plays a part in the absorption

of fats from the intestine.

All body tissues are bathed in lymph,

a watery fluid derived from the blood-

stream. Much of this fluid is returned to

LYME DISEASE LYMPHATIC SYSTEM

L

Lymphatic

vessel

Abdominal

lymph

nodes

Axillary

(armpit)

lymph

nodes

Thymus

Inguinal

(groin) lymph

nodes

Spleen

Chest

lymph

nodes

Cervical (neck)

lymph nodes

LYMPHATIC SYSTEM