The genital tract: how does it change?
The genital tract undergoes a series of changes throughout life, the majority of which occurs during puberty. In the first stages of development, female and male genitalia are indistinguishable and even though gender is determined during fecundation, it becomes clinically apparent at the 12th week of embryonic life, during which, in the absence of androgens, the differentiation of tissues leads to the external feminine phenotype. In females, ovarian differentiation begins at about 8 weeks gestation, stem cells differentiate themselves in oogonium and then in oocytes with the first meiotic cell division until puberty. Under the influence of oestrogens, Muller’s ducts differentiate themselves in internal genitalia, and Wolff’s ducts form the female external genitalia, of which the lower vagina, the labia and the clitoris. The genital system can be divided into two triangles, the anterior urogenital triangle and the posterior anal triangle. The anterior triangle includes the external genitalia and the urethral opening, commonly referred to as vulva.
The vulva: what does it include?
The vulva includes:
- Labia majora: two fibroadipose folds, after puberty they are covered in hair and rich in sebaceous, apocrine and eccrine glands
- Labia minora: two folds with no hair that are constituted by neurovascular structures, sebaceous follicles, sweat glands and muscles
- Batholin’s glands: secrete mucus to maintain an adequate lubrication
- Clitoris: the feminine erectile organ is 5 mm long in children and in pre-pubertal age and 1-2 cm in mature females
- Vaginal orifice: surrounded by the hymen, incomplete mucous membrane that matures during puberty under the influence of oestrogens, becoming thicker and more elastic.
The internal feminine genitalia are:
- Vagina: limited by bladder, urethra and rectum
- Uterus: fibro-muscular organ divided into the lower cervix and upper uterine body. It is composed of three layers: endometrium, myometrium, and perimetrium. At birth the cervix is twice the length of the uterine body. During puberty, this ratio is inverted and in adult women the uterine body is two or three times the size of the cervix
The uterine annexes consist of the ovaries and of the fallopian tubes.
- The Fallopian tubes: their function includes the transportation of ovules and spermatozoa and the creation of an environment adequate for conception
- Ovaries: vary on the basis of age, menstrual cycle and under hormonal influence.
A correct understanding of the feminine reproductive system is crucial for an accurate evaluation and treatment of developmental anomalies.