The internal genital organs in female include vagina, uterus, fallopian tubes and the ovaries (See fig1.2 below). These require special instruments for inspection. Knowledge of the position and function of these organs is also essential for the accurate examination of pregnant women, and a safe labor and delivery.
Vagina - the vagina is a muscular passage, 8-10 cm in length, between the cervix and the external genitalia. The secretions that lubricate the vagina come from glands in the cervix. It is very small but sufficient to make the surface moist.The vagina has four walls namely, anterior, posterior and two lateral walls. The length of the anterior wall measures 7 cm and the posterior wall is about 9 cm. The vagina serves as the excretory channel for menstrual blood and uterine secretions, an organ for sexual intercourse and passage for the fetus during birth.
Uterus - this is a hollow, muscular organ situated between bladder and rectum; in which a fertilised ovum embeds and develops into a fetus. Its principal function is protecting and nourishing the fetus until birth. During pregnancy, the muscular walls of the uterus become thicker and stretch in response to increasing fetal size. It also accommodates increasing amounts of amniotic fluid (the waters surrounding the fetus, contained in a bag of fetal membranes), and the placenta (the structure that delivers nutrients from the mother to the fetus). The uterus has three parts (see Figure 1.2 below):
Body or corpus - the part between the isthmus and the opening of the fallopian tubes. The part that is above the opening of the fallopian tubes is called the fundus.
Isthmus - a constricted part situated between the body and the cervix.
Cervix- the lower most of the uterus which is cylindrical in shape. It has two openings the internal os (opening) and the external os with the cervical canal in between.
The uterine wall consists of three layers:
Perimetrium - the outermost thin membrane layer covering the uterus.
Myometrium - consists of thick muscular middle layer.
Endometrium - the mucus lining of the endometrial cavity; an innermost layer of the uterus which thickens during the menstrual cycle. This is the tissue that builds up each month in a woman of reproductive age, under the influence of the female reproductive hormones.
Fallopian Tube - paired structures which are attached to the lateral angle of the uterine cavity. It has four parts interstitial ( the part inside the uterine wall), the isthmus (the straight part), ampulla (the tortuous part) and the infundibulum.
Ovary - are paired sex glands or organs; each is attached to the uterus by the utero-ovarian ligament. These paired female reproductive organs produce the eggs (ova).
