Anatomy and Physiology of Children and Adolescents - M. R. Sapin 2007

Genitourinary System
Reproductive System
Female Reproductive Organs - Age-Related Features of Female Reproductive Organs

In a newborn girl, the Ovary is cylindrical in shape. During the second childhood period (8–12 years), the shape of the ovary becomes ovoid. The length of the ovary in a newborn girl is 1.5–3 cm, and its width is 4–8 mm. In adolescence and youth, the length of the ovary increases up to 5 cm, the width reaches 3 cm, and the thickness is 1.5 cm. The mass of the ovary in a newborn is 0.16 g, During the first childhood period (4–7 years) it is 3.3 g, and in youth it is 6.03 g. In women over 45–55 years of age, the mass of the Ovaries gradually decreases. The surface of the ovaries is smooth in newborns and during infancy. In adolescence, irregularities and bumps appear On the surface of the ovaries due to the enlargement of maturing follicles and The formation of corpora lutea. Primary follicles appear in the ovarian tissue during infancy. In adolescence, secondary (vesicular) follicles are formed in the cortical substance of the ovaries, which appear on organ cross-sections as cavities with clear contents.

In newborn girls, the ovaries are located above the pelvic inlet and tilted anteriorly. By 3–5 years of age, the ovaries acquire a transverse position. By the first childhood period (4–7 years), the ovaries descend into the pelvic cavity, where they assume the position characteristic of an adult woman.

The Uterus in a newborn girl, during infancy and early childhood (up to 3 years), is cylindrical in shape and flattened anteroposteriorly. During the second childhood period, the uterus becomes rounded, and its fundus widens. In adolescence, the uterus becomes pear-shaped. This shape is maintained in the adult woman as well. The length of the uterus in a newborn girl reaches 3.5 cm (²/₃ of the length is the cervix). By 10 years of age, the length of the uterus increases to 5 cm, in youth to 5.5 cm, and in an adult woman the length of the uterus is 6–8 cm. During the second childhood period (8–12 years), the lengths of the uterine body and cervix are almost equal. In adolescence, the length of the uterine body increases, and in youth it reaches 5 cm. The mass of the uterus increases slowly at first, and then rapidly. In a newborn girl, the mass of the uterus is 3–6 g, in adolescence (12–15 years) it is approximately 16.5 g, and in youth (16–20 years) it is 20–25 g. The uterus achieves its maximum mass (45–80 g) at the age of 30–40 years, and after 55 years its mass gradually decreases.

The cervical canal in a newborn girl is wide and usually contains a mucous plug. The mucous membrane of the uterus forms branched folds, which smooth out by 6–7 years of age. Uterine glands are few in number. As the girl grows older, the number of glands increases and their Structure becomes more complex. By Puberty, the glands become branched. The muscular coat of the uterus, which is poorly developed in a newborn girl, thickens as the uterus grows, especially after 5–6 years of age.

In newborn girls, the uterus is located high, protrudes above the Pubic Symphysis, and is tilted anteriorly. The cervix points downward and backward. The uterine ligaments are weak, causing the uterus to be easily displaced laterally. As the dimensions of the pelvis increase and due to the descent of the Organs located within it, the uterus gradually shifts downward and, by adolescence, assumes the position characteristic of a sexually mature woman. In elderly and senile age, due to the reduction of adipose tissue in the pelvic cavity, the mobility of the uterus increases.

The uterine tubes in a newborn girl are tortuous and do not come into contact with the ovaries. During puberty (adolescence), due to the growth of the uterus and its broad ligaments and the enlargement of the pelvic cavity, the uterine tubes lose their tortuosity, descend inferiorly, and approach the ovaries. The length of the Uterine tube in a newborn girl is approximately 3.5 cm, and during puberty its length increases rapidly. In elderly women, the walls of the uterine tube become sharply thinned due to Atrophy of the muscular coat. The folds of the mucous membrane smooth out.

The Vagina of a newborn girl is short (2.5–3.5 cm) and curved in an arch, with the anterior wall shorter than the posterior. The lower section of the vagina faces anteriorly. As a result, the longitudinal axis of the vagina forms an obtuse angle open anteriorly with the axis of the uterus. The vaginal opening is narrow. Up to 10 years of age, the vagina changes very little, but grows rapidly during adolescence.

In a newborn girl, the mons pubis is convex, and the Labia Majora are loose and appear edematous. The Labia minora are not completely covered by the labia majora. The Vestibule of the vagina is deep, especially in its anterior part, where the external urethral orifice is located. The vestibule of the vagina is bounded by the labia majora in its posterior third, and by the labia minora in the anterior sections. The hymen is dense. The vestibular glands are poorly developed in a newborn girl.

Review and Self-Assessment Questions:

1. Name the Functions performed by the ovaries. Indicate where the ovaries are located.

2. Name the PARTS OF THE uterine tube and the uterus. What functions do the uterine tubes and the uterus perform in the female body?

3. What ligaments does the uterus have, and where are they located relative to the uterus?

4. Indicate the ducts of which glands open into the vestibule of the vagina. Where are these glands located?