The menstrual cycle is governed by hormonal changes in the ovaries and uterus that allow for egg production and the potential for pregnancy. It occurs in three phases - the follicular phase where an egg develops and is released, ovulation where the egg is released, and the luteal phase where the uterus prepares for potential pregnancy. Common premenstrual symptoms like acne, breast tenderness, and mood changes occur in 20-30% of women prior to menstruation. The cycle is regulated by hormones like GnRH, FSH, and LH that signal the pituitary and ovaries. FSH stimulates follicle development in the follicular phase and LH triggers ovulation.

1. Monthly Ovarian Cycle (Menstural Cycle)
The menstrual cycle is the regular natural changes that occurs in
the uterus and ovaries that make pregnancy possible. The cycle is required for the
production of eggs, and for the preparation of the uterus for pregnancy. Up to 80% of women
report having some symptoms during the one to two weeks prior to menstruation
Common Symptoms :
1. acne
2. tender
3. breasts
4. bloating
5. feeling tired
6. irritability
7. mood changes.
These symptoms interfere with normal life and therefore qualify as
premenstrual syndrome in 20 to 30% of women. In 3 to 8%, they are severe.
The first period usually begins between twelve and fifteen years of age, a point in time
known as menarche. They may occasionally start as early as eight, and this onset may
still be normal
The menstrual cycle is governed by hormonal changes.[
These changes can be
altered by using hormonal birth control to prevent pregnancy.[
Each cycle can be divided
into three phases based on events in the ovary (ovarian cycle) or in the uterus (uterine
cycle). The ovarian cycle consists of the
1.follicular phase,
2.ovulation,
3.luteal phase ,
whereas the uterine cycle is divided into
1.menstruation,
2.proliferative phase
3.secretory phase

3. Hormones :-
1.Gonadotropic Releasing Hormone (GnRH) ;
Gonadotropin-releasing hormone (GnRH), also known as luteinizing
hormone-releasing hormone (LHRH) and luliberin, as well as gonadorelin (INN), is
a trophic peptide hormone responsible for the release of follicle-stimulating
hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary. GnRH is
synthesized and released from GnRH neurons within the hypothalamus.
in the absence of these hormone , the ovaries remain inactive , which in the
case throughout childhood ,when almost no pituitary gonadotropic hormone are
secreted.
2. Follicle Stimulating hormone (FSH)
Follicle-stimulating hormone (FSH) is aglycoprotein hormone found in
humans and other animals. It is synthesized and secreted by gonadotrophs of theanterior
pituitary gland, and regulates the development, growth, pubertal maturation, and
reproductive processes of the body.
Follicular phase of the ovarian Cycle ;
When a female child is born each ovum is surrounded by a single
layer of granulose cells , the ovum,with the granulose cell sheath, is called a
Primordial follicle , the granulose cells provide nourishment for the ovum and to
secrete an oocyte maturation-inhibiting factor that keeps the ovum suspended in its
primordial state in the prophase stage of meiotic division.

4. Luteinizing hormone
Luteinizing hormone (LH, also known as lutropin and
sometimeslutrophin is a hormone produced by gonadotropic cells in the anterior
pituitary gland. In females, an acute rise of LH ("LH surge") triggersovulation
and development of the corpus luteum