Ovaries

Generality

The ovaries are the female gonads.

Their job is to secrete the egg cells - the gametes of the female gender - and the sex hormones typical of women - namely estrogens and progesterone.

In number of two and similar in shape to a bean, the ovaries reside in the pelvis, to be precise in the so-called iliac fossa, to the right and to the left of the uterus.

From the histological point of view, the structure of the ovaries is quite complex. In fact, it includes 4 different regions, which are: the germinal epithelium of the ovary, the albuginea tunic, the ovarian cortex and the ovary medulla.

The ovaries can be protagonists of various morbid conditions, including: ovarian cysts, ovarian polycystosis, ovarian tumors, primary female hypogonadism and ovarian torsion.

Short review of human gonads

The gonads are the primary sexual organs of the reproductive system (or genital apparatus) of the human being.

They are endocrine glands, which have the important function of secreting:

The gametes, that is, the sex cells necessary for reproduction
sex hormones, fundamental for the development of secondary sexual characteristics and for the control of the genital apparatus.

What are ovaries?

The ovaries (in the singular ovary, but also ovary or ovary ) are the female gonads, that is the endocrine glands which, in women, represent the sexual organs responsible for the production of gametes and sex hormones.

IN MAN ARE YOU EQUIVALING A?

In male individuals, the ovaries are equivalent to the testicles .

Anatomy

In number of two and similar in shape to a bean, the ovaries reside in the pelvis (or pelvic cavity), to the right and to the left of the uterus (central position), in a region that the anatomists call ovarian fossa .

Being in the ovarian fossa, each ovary borders, anteriorly, with the external iliac artery and, posteriorly, with the ureter and the internal iliac artery.

The ovaries are whitish in color and, in an adult woman, generally measure 2-4 centimeters in length, 2-3 centimeters in width and 1-2 centimeters in thickness.

Each ovary communicates with the uterus, by means of important tubular structures, called fallopian tubes .

HISTOLOGY

In the ovaries, histology experts recognize at least 4 different regions, each with different functions:

The germinal epithelium of the ovary . Smooth and of soft consistency, it represents the outermost region. The cellular elements that constitute it are called, very simply, cells of the germinal epithelium of the ovary.
The tunica albuginea (or tunic albuginea ). It is the region located just below the germinal epithelium. It is a fibrous connective tissue with a very hard consistency. Its functions are to support and protect the delicate underlying tissues.
The ovarian cortex (or ovarian cortex ). It is the region that resides under the albuginea tunic. Contains so-called ovarian germ cells (or ovarian follicles) and stromal cells of the ovary.
The germ cells of the ovary are the cellular elements, which give rise to the female gametes; the stromal cells of the ovary, on the other hand, are the cells used to support germ cells and the secretion of female sex hormones.
The ovary medulla (or ovarian medulla ). It is the deepest region of the ovary. It contains blood vessels, lymphatic vessels and nerve structures, which serve to nourish, innervate and maintain healthy all the cells constituting the ovaries (from those of the ovarian cortex to those of the germinal epithelium of the ovary).

For the avoidance of doubt, it is important to point out that some histology texts include the albuginea tunic in the ovarian cortex, thus recognizing only 3 different regions in the ovaries.

It is simply an alternative way of describing the same thing.

LIGAMENTS

A ligament is a band of fibrous connective tissue with the task of holding together two different anatomical elements (eg: two bony portions) and / or keeping a well-defined organ at a certain location.

The ligaments that have relations with the ovaries are: the suspensory (or lumbo-ovarian) ligament, the own ligament (or utero-ovarian), the mesovary and the tube-ovarian ligament .

The function of the ligaments of the ovaries is to connect the latter to the neighboring organs, so that they remain firm in their natural seat.

Suspensory (or lumbo-ovarian) ligament: it is the structure that connects the ovaries to the pelvic wall. It consists of fibrous connective tissue and smooth muscle fibrocells.
Own ligament (or utero-ovarian): it is the structure that connects the ovaries to the supero-lateral portions of the uterus. It consists of fibrous connective tissue and smooth muscle fibrocells.
Mesovar: is a portion of the so-called broad ligament of the uterus. The broad ligament of the uterus is the structure that connects the uterus to the pelvic walls and pelvic floor.
Tube-ovarian ligament: it is the structure that unites the outer surface of the so-called tubal pavilion (fallopian tube) to the superior pole of the ovaries.

Functions

The ovaries are responsible for producing the so-called egg cells and sex hormones known as estrogens, progesterone and testosterone .

What are sex hormones?

The sex hormones produced by the ovaries, as well as those produced by the testicles, belong to the category of steroid hormones .

Steroid hormones are derivatives of cholesterol .

PRODUCTION OF EGG CELLS: THE OVOGENESIS

The process of production and maturation of egg cells by the ovaries is called ovogenesis .

The highlights of oogenesis are basically three: the follicular phase, the ovulatory phase (or ovulation ) and the luteal phase .

The starting point of oogenesis, the follicular phase is the moment in which the ovaries, after a precise hormonal stimulation, produce and bring to maturity, inside a follicle, the future egg cell (NB: in this phase the cell egg takes the name of primitive egg cell).
Following the follicular phase, the ovulatory phase is the moment in which, following a hormonal stimulus different from the previous one, the now mature egg cell detaches from the follicle (and from the ovary) and nestles in the fallopian tubes, ready to meet with an eventual spermatozoon.
Finally, the final stage of oogenesis, the luteal phase is the moment in which the follicle becomes a corpus luteum and, in case of failure of the egg cell to fertilize, menstruation occurs.

The table below is a summary, with more details, of what has just been described.

Phase	Description	days
Follicular phase	The brain releases the follicle stimulating hormone (FSH), which, through the bloodstream, reaches the ovaries and stimulates them to produce a series of primitive oocytes (or ovarian follicles). Of these follicles, only one survives and becomes the actual egg cell, ready for fertilization (if it encounters a sperm). FSH also stimulates the secretion of estrogens: these are essential for regulating the production of follicles.	From the 1st to the 14th day
Ovulatory phase	It is the moment that coincides with the release of the mature egg cell into the fallopian tubes. The release of the oocyte occurs upon stimulation of the luteinizing hormone (LH). In this phase of the menstrual cycle, the cervix produces large amounts of mucus, which has the purpose of capturing the man's sperm, during sexual intercourse.	Between the 14th and the 15th day
Luteal phase	It is the moment when the ovarian follicle turns into the so-called corpus luteum. The formation of the corpus luteum promotes the secretion of progesterone, while it reduces that of FSH and LH. Towards the end of the luteal phase, the corpus luteum tends to progressively regress and the levels of progesterone decrease. If the egg cell has not been fertilized, the most superficial layer of the uterus (endometrium) goes into necrosis and flakes. This starts menstruation.	From the 16th to the 28th day

FEMALE SEXUAL HORMONES: ESTROGENES AND PROGESTERONE

In women, the most important sex hormones produced by the ovaries are estrogen and progesterone. Compared to the latter, testosterone is a marginal presence.

The task of estrogens is to control the development of secondary sexual characteristics, ie regular:

Breast and pubic hair growth;
The maturation of the uterus and vagina;
The enlargement of the basin;
The typically female distribution of adipose tissue, in the hips, legs and breast;
The onset of menstruation and all changes in the uterus during the menstrual cycle.

The function of progesterone, instead, is to prepare the uterus for a possible pregnancy, to prepare the mammary glands for a possible lactation and, finally, in case of failed fertilization, to promote menstruation.

Testosterone

Testosterone is the main sex hormone of the male gender. In fact, it is equivalent to estrogen in the female gender, therefore it has the task of controlling the development of the secondary sexual characteristics of man.

In women, testosterone is present in very small quantities and begins to play a significant biological role at the end of menopause.

In female subjects, testosterone production depends not only on the ovaries, but also on the adrenal glands.

Aging and curiosity

Aging coincides with a decline in the functional capacity of the ovaries and with the exhaustion of the egg cells.

At birth, a woman's ovaries contain all the primitive oocytes (that is, unripe egg cells), which in the course of life could at least participate in the first phase of oogenesis (follicular phase).

Some interesting studies have shown that, immediately after birth, the aforementioned primitive oocytes would be about one million and that, during the course of life, only 500 of them undergo the ovulation process. This means that 99.95% of primitive oocytes present at birth undergoes degeneration, while only a small 0.05% is the protagonist of the ovulatory phase of oogenesis.

It is a fact that, in parallel with the decline in the functional capacity of the ovaries and the exhaustion of the egg cells, the risk of problems during pregnancy and chromosomal alterations affecting the embryo increases (at the moment of conception).

Illnesses

The ovaries can be subject to numerous medical conditions, some of which are also very serious from the clinical point of view.

Among the medical conditions that have ovaries as protagonists, they deserve a special mention:

The so-called ovarian cysts;
Ovarian tumors;
The polycystic ovary;
Female primary hypogonadism;
Ovarian torsion;
The hyperthecosis.

OVARIAN CYSTS

An ovarian cyst is a bag filled with liquid or solid material, which takes shape outside or inside the ovaries.

In most cases, ovarian cysts are something physiological, which depends on the menstrual cycle (functional ovarian cysts); more rarely, they are the consequence of benign or malignant tumors or of pathological conditions such as endometriosis or polycystic ovary (pathological or non-functional ovarian cysts).

There are different types of functional ovarian cysts and different types of pathological ovarian cysts. Among the types of functional ovarian cysts are follicular cysts, luteal cysts and thecal cysts ; the types of pathological ovarian cysts include dermoid cysts, cystadenomas, cysts due to endometriosis and cysts due to polycystic ovary syndrome.

In general, ovarian cysts are asymptomatic; if, however, they become large, they break or block the flow of blood to the ovaries, they can be responsible for various symptoms, including pelvic pain, the need to urinate often, changes in the normal menstrual cycle, etc.

CANCER THE OVARIES

Also known as ovarian cancer, ovarian cancer or ovarian cancer, ovarian cancer is a malignant neoplasm that originates in an ovarian cell.

Currently, the precise causes of ovarian cancer are unknown. According to some doctors, factors favoring advanced age, a high number of ovulations, obesity, endometriosis, estrogen and / or progesterone-based hormone replacement therapies and a family history of ovarian cancer would be factors.

The most common symptoms of ovarian cancer are: back pain, loss of appetite, frequent urination, pelvic pain during sexual intercourse, diarrhea and ascites.

POLYCHISTIC OVA

The polycystic ovary, or polycystic ovary, is a particular medical condition characterized by enlarged ovaries filled with cysts of various sizes and by a triad of characteristic symptoms, which are:

Amenorrhea (absence of menstruation),
Hirsutism (increase in hair),
Obesity.

The polycystic ovary depends on an abnormal increase in the levels of male hormones (androgens) in the blood. Elevated blood levels of androgens, in fact, compromise the normal development of the Graafian follicles, causing an unusual scarring, characterized by the appearance of cysts.

The abnormal increase in male hormone levels in the blood is an endocrine alteration, which doctors call hyperandrogenism .

FEMALE HYPOGONADISM OF PRIMARY TYPE

To understand what primary female hypogonadism is, it is necessary to review the meaning of hypogonadism, female hypogonadism and primary hypogonadism:

Hypogonadism is the medical term that indicates a more or less marked reduction in the functional activity of the gonads.
Female hypogonadism is a medical condition characterized by reduced functionality of the ovaries, followed by a minor or no production of estrogens, progesterone and derived hormones.
Primary hypogonadism is hypogonadism resulting from a problem inherent in the gonads. It is distinguished from secondary hypogonadism, which depends on defects of the hypothalamus or pituitary gland (NB: hypothalamus and pituitary glands are the glands of the nervous system that regulate the activity of the gonads).

In light of this, the primary type of female hypogonadism is that medical condition characterized by a problem inherent in the ovaries, a problem on which the functional deficiencies of the ovaries depend.

OVARIAN TORSION

Ovarian torsion is the medical term that indicates the abnormal rotation of an ovary, around its vascular peduncle, with interruption of blood flow inside the artery or ovarian vein.

Ovarian torsion is responsible for severe pain in the lower abdomen, left or right, depending on the ovary involved. Very often, nausea and vomiting are associated with pain.