In order to fully understand the transmission, effccts and
complications of STD and to be able to communicate your conerns
to the doctor, you must have a reasonable knowledge of the anatomy
(structure) of the sexual and reproductive system and the
differnt types of sexual practices.
Male anatomy (Fig 1)
Anus - the opening through which faeces passes.
Bladder - the sac which contains the urine.
Epididymis - this is a coiled structure which lies
at the back of the testis. It acts as a storehouse for sperm.
An infection of the epididymis is known as epididymitis.
Sterility may result if scarring seals off both epididymes.
Glans penis - this is the head of the penis. In uncircumcised
men, the glans penis is covered by the prepuce (foreskin). An
infection of the glans penis and/or the prepuce is known as balanitis.
Penis - the erectile male organ which conveys
urine to the outside and sperm into the vagina during sexual
Prepuce - the foreskin which covers the glans penis.
An infection of the prepuce and/or glans penis is known as balanitis.
The prepuce is removed by circumcision.
Prostate - this gland lies at the neck of the bladder
and encircles the urethra. It contributes fluid to semen. An
infection of the prostate gland is known as prostatitis.
Rectum - the lower end of the large intestine
that ends in the anus. The rectum is lined by a thin mucous membrane
and is not naturally lubricated during sex like the vagina. Anal
and rectal sex is, therefore, more likely to cause tears in the
mucous membrane lining, facilitating the entry of germs. This
is why anal or rectal sex is said to be very risky and this may
be one reason why infections such as Hepatitis B and AIDS are
particularly common among homosexual men. The slight bleeding
associated with the passage of hard stools is one indication
of how thin the mucous membrane lining of the rectum is.
Scrotum - the sac which contains the testes.
Testis - one of the two sex organs in the scrotum.
Urethra (urine pipe) - the tube through which urine
from the bladder flows to the outside. An infection of the urethra
is known as urethritis. The male urethra is about 20 cm
long compared to 4 cm in the female. Theis makes it more difficult
for germs to enter the bladder and this is why cystitis (bladder
infection) is relatively uncommon in men.
Vas deferens - the duct which connects the epididymis
to the urethra. Sperm travels through the vas deferenss into
Female anatomy (Fig 2)
Anus - the opening through which faeces passes. You
will also notice from the figure that the anus is quite close
to the vagina. This makes it possible for infected secretions
from the vagina to flow backwards into the anus and rectum,
causing an infection there. Rectal gonorrhoea in women is believed
to be due to contamination by vaginal secretions rather than
through actual rectal intercourse.
Bartholins gland - this is one of two glands which lie
in the lower third of each labium majus. It secretes a fluid
during sexual arousal and lubricates the vagina so that intercourse
can take place without much discomfort. Infection of the Bartholins
gland may lead to the formation of a Bartholins abscess.
Bladder - the sac which stores urine. An infection
of the bladder is known as cystitis.
Cervix - the neck of the uterus (womb) which protrudes
into the vagina. It is pierced by a canal which connects
the cavity of the uterus with the vagina. The canal is called
the cervical canal and its opening is called the os. An infection
of the cervix is known as cervicitis. Infection there may spread
into the uterus through the cervical canal.
Clitoris - the sensuous structure located at the top
of the labia. It is the female equivalent of the penis.
Fallopian tube - one of two tubes through which the
egg travels down from the ovary into the uterus. An infection
of the Fallopian tube is called salpingitis. However, infection
there commonly involves other adjacent structures inside the
pelvis such as the uterus and the ovary and most doctors use
the composite term, pelvic inflammatory disease (PID)
to refer to infection of any one or more of these sites.
Labium majus (major lip) - one of the two larger lips
of the vagina.
Labium minor (minor lip) - one of the two smaller lips
of the vagina.
Ovary - one of two glands that produce eggs and the
Rectum - the lower end of the large intestine that
ends in the anus.
Urethra - the tube through which urine from the
bladder flows to the outside. An infection of the urethra is
known as urethritis. The female urethra is about 4 cm long compared
to 20 cm in the male. This makes it easier for germs to go straight
through the urethra into the bladder and this is why women are
more prone to develop cystitis (bladder infection).
Uterus - the womb. It consists of the body and the
neck (cervix). The cervix iopens into the vagina and the
body of the uterus is joined in each corner by the Fallopian
tube. An infection of the uterus commonly involves other structures
within the pelvis such as the Fallopian tubes and the ovaries
and is called pelvic inflammatory disease (PID).
Vagina - the birth canal which also accepts the penis
during sexual intercourse.The adult vagina is lined by a mucous
membrane that is several cell layers thick.This is why the vagina
can withstand the rigors of childbirth. The vagina is also
lubricated during sexual arousal and this allows intercourse
to take place comfortably and with the minimum of trauma.