genito-urinary medicineThe branch
of medicine concerned with sexually
transmitted infections.
genome, humanThe complete set of
human genetic material. The human
genome consists of 23 chromosomes,
which, together, contain about 30,000
genes. All body cells contain 2 sets of
the 23 chromosomes, one set inherited
from the father and the other from the
mother. An international research pro-
gramme, the Human Genome Project,
was launched in 1990 with the aim of
identifying all the human genes. The
first rough draft of the project was pub-
lished in 2000.
gentamicinAn antibacterial druggiven
by injection to treat serious infections
such as meningitis and septicaemia.
Gentamicin can damage the kidneys or
innerear if the dosage is not carefully
controlled. The drug is also used in eye
and ear drops but is unlikely to cause
serious side effects with this use.
gentian violetA purple dye used to
makebacteriavisible under a micro-
scope. It was also used as an antiseptic.
genu valgum The medical term for
knock-knee.
genu varumSee bowleg.
geriatric medicineThe medical spe-
cialty concerned with care of the elderly.
Elderly people require specialist medical
treatment because they respond differ-
ently from younger people to illness
and its treatment. Physical and mental
decline due to agingcan mean that ill-
nesses are more severe in older people.
Because the liver becomes less efficient
with age, drug dosages for elderly peo-
ple need to be carefully controlled to
avoid dangerous side effects. Geriatri-
cians also help older people to cope
with everyday life following illness or
injury. (See also rehabilitation.)
germThe popular term used to des-
cribe any microorganisms that cause
disease, such as virusesand bacteria.
(See also germ cells.)
German measlesThe common name
for the viral infection rubella.
germ cell An embryonic cellwith the
potential to develop into a sperma-
tozoonor ovum, which, on maturity, are
called gametes. The term also describesdetermine whether particular genetic de-
fects are present in an individual’s DNA.
Genetic probes are mainly used in ante-
natal diagnosis of genetic disorders, and
in investigating whether people with a
family history of a genetic disorder carry
the defective gene themselves.
geneticsThe study of inheritance, the
chemical basis by which characteristics
are determined, and the causes of the
similarities and differences among indi-
viduals of a species or between different
species. Branches of human genetics
include population genetics, which stu-
dies the relative frequency of various
genesin different races; molecular gen-
etics, which is concerned with the
structure, function, and copying of
DNA; and clinical genetics, which is
concerned with the study and preven-
tion of genetic disorders.
genital herpesSee herpes, genital.
genitaliaThe reproductive organs, esp-
ecially those that are external. The male
genitalia include the penis, testes(in the
scrotum), prostate gland, seminal vesi-
cles, and associated ducts, such as the
epididymisand vas deferens. The female
genitalia include the ovaries, fallopian
tubes, uterus, vagina, clitoris, vulva, and
Bartholin’s glands.
genitalia, ambiguousA group of con-
ditions in which the external sex organs
are not clearly male or female, or in
which they appear to be those of the
opposite chromosomal sex. This may
result from an abnormality of the sex
chromosomesor a hormonal disorder
(see hermaphroditism; sex determin-
ation; adrenal hyperplasia, congenital).
genital ulcerAn eroded area of skin on
the genitalia. The most common cause
is a sexually transmitted infection, partic-
ularly syphilisand genital herpes (see
herpes, genital). Chancroid and granu-
loma inguinaleare tropical bacterial
infections that cause genital ulcers.
Lymphogranuloma venereumis a viral
infection producing genital blisters.Beh-
çet’s syndromeis a rare condition that
causes tender, recurrent ulcers in the
mouth and on the genitals. Cancer of
the penis or vulva may first appear as a
painless ulcer with raised edges.
genital wartsSee warts, genital.
GENETICS GERM CELL
G