Female genital system (histology)

The female reproductive system (organa genitalia feminina) consists of paired ovaries (ovaria) and fallopian tubes (tubae uterinae), uterus (uterus), vagina (vagina) and external genital organs.

The fallopian tubes, the uterus attached to them and the vagina connected to them, create a cavity system that leads to the outside of the body. The fallopian tubes, which widen at the end like a funnel, communicate with the abdominal cavity and are connected to the ovaries. Eggs mature in the ovary during sexual maturity, and after subsequent ovulation are released into the fallopian tube, where fertilization can occur. The ovary also produces most of the female sex hormones that affect the menstrual and ovarian cycles, and in turn participate in the secretion of gonadotropic hormones from the pituitary gland. The uterus is used to nestle the fertilized egg, where it travels through the fallopian tube from the ovary.

Ovary


The ovary has a flattened, ovoid shape, weight: 6–10 g.

In the hilum, the mesovarium is connected to the lig. latum uteri, the surface is covered by a single-layered flat to cubic "germ" epithelium, in the hilum it passes into the mesothelium. The germinal epithelium contains microvilli, sometimes kinocilia, numerous pinocytotic vesicles are present apically, and mitochondria are found basally. In the hilum is the entry of bundles of smooth muscle cells from the mesoovary. Interstitial hilar cells have the character of steroid- androgen- producing cells (large GER, GK, many tubular-type mitochondria, lipid inclusions, Reineke's crystalloids). Beneath the epithelium is the tunica albuginea, which has a whitish color and is made up of dense collagen fibers.

Ovarian hyperplasia leads to virilization.

We distinguish the cortex (zona corticalis) and the medulla (zona medularis, zona vasculosa).

Cortex
The cortex of the ovary consists of sparse collagen tissue, ovarian follicles, fibroblasts, rare smooth muscle cells, a network of collagen and reticular fibers. It also contains special fibroblasts that have fat droplets and react with hormones to change from protein- producing cells to steroid- producing cells (thecal cells).

During the fertile period, many fibroblasts are present, after menopause they decrease (reticular and collagen fibers increase relatively).

Medulla
The medulla is formed by a denser collagenous tissue. It contains fewer cells, more collagen and reticular fibers. It is richly vascularized and innervated.

Fallopian tube
The fallopian tube is a movable muscular tube with a size of 6-8 × 100-150 mm, connects the uterus with the abdominal cavity. It creates a suitable environment for fertilization of the egg (cilia oscillating in reverse). Secretion of glands contributes to the nutrition of the oocyte. In the period of ovulation, fimbriae get closer to the ovary, this triggers the mechanism of blood vessel congestion and the fallopian tube becomes more rigid.

Its main function is to transport the oocyte to the uterus with the help of cilia and smooth muscle peristalsis.

The fallopian tube has 4 parts:


 * pars uterina (developed by T. muscularis),
 * isthmus,
 * ampulla (pronounced eyelashes),
 * infundibulum (numerous cilia) with fimbria.

Tunica mucosa
It contains long, dissected, longitudinally arranged cilia, which are highest in the ampullary region and decrease towards the uterus. Algae anastose each other, forming a complex labyrinth.

Algae are divided into:


 * secondary
 * tertiary.

Lamina epithelialis is lined with a single-layered columnar epithelium containing ciliated and secretory cells.

Cilia cells. They are very numerous in the infundibulum. They contain glycogen granules, ciliary apparatus and kinocillia oscillating to the uterus. Their nuclei are large oval, GER and GK on the contrary small, numerous mitochondria are collected around the basal bodies, rarely lysosomes occur here. Secretory they have only microvilli apically. In the cytoplasm there is a very developed GER, large GK and an electron-dense serous large secretory granule.

Lamina propria mucosae is made up of loose collagenous connective tissue.

Tunica muscularis
The tunic muscularis thins towards the infundibulus. It contains two layers of smooth muscle cells:


 * indoor circular,
 * external longitudinal.

Tunica serosa
The tunica serosa consists of sparse collagenous tissue with a single-layer flat mesothelium. It is richly supplied with blood vessels.

Uterus
The uterus consists of 4 parts:
 * corpus
 * fundus
 * isthmus
 * cervix.

Tunica mucosa (endometrium)
The lamina epithelialis consists of a single-layered cylindrical epithelium with ciliated cells.

The lamina propria mucosae contains a special collagen fiber with a higher number of fibroblasts. These are changed by hormonal stimulation into decidual cells, which serve for the initial nutrition of the fetus. The intercellular mass is amorphous, has fewer fibers, where reticular fibers predominate. This layer is rich in glandulae uterinae. They are simple tubular glands (in myometrium and branching) formed from a 1-layered cylindrical epithelium without ciliated cells.

It has two layers:


 * The zona functionalis is the superficial, thicker layer that is washed away. Contains rare col. ligament., dilated lymph. vessels and spiral arterioles (arteriae arcuatae),
 * The zona basalis is located near the myometrium and is only 0.5 – 1.5 mm high. Here we find bases of glands, more bb. and a network of reticular fibers. Direct arterioles (arteriae arcuatae) run here.

Tunica muscularis (myometrium)
The myometrium is the thickest layer with a thickness of 15 mm. It contains layers of smooth muscle cells, few collagen fibers and no elastic fibers.

It has 4 layers:


 * longitudinal,
 * spirals,
 * spirals,
 * longitudinal.

During pregnancy, it hypertrophies up to 500 mm, hyperplasia (cell division), the secretory activity of protein-secreting cells increases and collagen is formed. After pregnancy, the collagen dies off, shrinks, and is enzymatically degraded, and the tunica muscularis thus regains almost its original shape.

Tunica serosa (perimetrium)
The main part of the perimetrium is a thin layer of sparse collagenous tissue and the mesothelium (peritoneal lining). The tunica serosa forms the spaces that separate the uterus from the abdominal cavity. Ventrally we find excavatio vesicouterina, dorsally excavatio rectouterina ( Douglas space ), which reaches up to the vagina (fornix posterior). It passes laterally into the ligamentum latum uteri. At the edges, they form parametrial ligaments (lig. cardinale uteri, lig. vesicouterine, lig. sacurouterine), which are composed of dense collagenous tissue.

Tunica mucosa (endometrium)
The muscle layer is 0.5 – 1 mm thick, contains short glands that produce little mucinous secretion. During the cycle they remain narrow, almost unchanged, the uppermost layers are washed away.

Tunica muscularis (myometrium)
Muscle fibers are predominantly circular in orientation.

Cervix uteri
It is divided into two sections:


 * portio supravaginalis,
 * portio vaginalis.

Tunica mucosa (endometrium at portio supravaginalis)
It contains special algae, plicae palmatae, which are not washed away. The secretion of the glands depends on the phase of the cycle.

The lamina epithelialis is lined by a single-layered columnar epithelium that produces mucus. During ovulation, the secretion is thinner so as not to prevent the penetration of sperm, on the contrary, in the secretory phase and during pregnancy, it is thicker and thus prevents infection.

The lamina propria mucosae contains tubular glands (glandulae cervicales) that branch. They are lined with a single-layered cylindrical epithelium and secrete mucus.

Tunica mucosa (endometrium at portio vaginalis)
The lamina epithelialis is made up of a multilayered non-keratinizing squamous epithelium with glycogen-rich cells. We can see the transition between columnar and squamous epithelium.

The lamina propria mucosae extends into the epithelium through numerous papillae.

Tunica muscularis (myometrium)
Fibrous cells predominate over muscle cells in the myometrium. Muscle fibers are oriented mainly circularly.

Sheath


The vagina is a flattened hollow organ 8 cm long and 3 cm wide. The front wall is 2 cm shorter than the back, i.e. the fornix anterior is more caudal than the fornix posterior.

Tunica mucosa
It is formed by transverse eyelashes (rugae vaginales), longitudinal eyelashes (columna rugarum anterior et posterior). The mucous membrane undergoes changes during the menstrual cycle.


 * 1) menstrual phase: maximum desquamation
 * 2) proliferative phase: most glycogen, significant desquamation of bb; lactobacillus acidophilus splits glucose into lactic acid (disinfection)
 * 3) secretory phase: increasing mucosa (vaginal cytology)

The lamina epithelialis is lined by a multi-layered squamous epithelium. The cells contain glycogen granules, which cleave bacteria after desquamation, keratohyalin gran. and tonofibrils.

The lamina propria mucosae does not contain glands, is moistened by transudation from blood vessels and has few sensitive nerve endings. It has two layers:


 * externally from medium-dense collagen tissue,
 * internal of thin tissue with numerous elastic fibers, abundantly supplied thanks to thin-walled vessels, during menstruation, the number of otherwise rarely occurring lymph nodes and in general lymph cells (mainly leukocytes) that migrate to the epithelium increases.

Tunica muscularis
It forms bundles of smooth muscle cells in two layers:


 * inner circular
 * outer longitudinal.

Tunica adventitia
It is made of denser collagen tissue, has numerous elastic fibers and nerve and venous plexuses, contains nerve ganglia.

Labia maiora pudendi
The labia majora is made of sparse collagenous tissue, contains lobules of adipose tissue and a thin layer of smooth muscle cells called the tunica dartos. They are covered with skin in two layers:


 * the outer one is thicker, hairy, contains sebaceous and sweat glands, eccrine and apocrine,
 * the inner one is thinner with sebaceous and sweat glands.

Labia minora pudendi
The labia minora are made of thin collagen fibers, elastic fibers, and contain sebaceous and sweat glands.

Clitoris
It includes two small erectile bodies that end in the glans clitoridis. The clitoris is formed by a multi-layered squamous keratinized epithelium.

Glandulae vestibulares maiores (Bartholini)
They are the same glands as the glandulae bulbourethrales in the male. They have an ovoid shape, measure 1-2 cm. The type is tuboalveolar glands, which contain mucinous cells. It opens into the vestibulum vaginae.

Glandulae vestibulares minores
They are mucinous glands that open into the vestibule vaginae around the urethra.

Related articles

 * Menstrual Cycle
 * Cyclical changes in the female body
 * Gametogenesis
 * Hyperplastic endometrium (preparation)