Menstrual cycle and its phase

Hello students and friends, today we are going to learn what is the menstrual cycle, its phase, symptoms, complications, and how the uterine changes occur.

So, let's start with what is puberty?

• Puberty is the stage of life when childhood converts into adulthood.
• At this stage of life, the body will grow faster than at any other time.
• Development of secondary sexual characteristics.
• Male: 12-16 years
• Female: 10-16 years.

There are five signs of puberty, given by Thanners and Marshal(scientists)-

1. Thelarchae- Development of breast
2. Adrenarche- Development of axillary hair(underarm hair)
3. Pubarchae- Pubic hair
4. Increase in height
5. Menarche- In girls starting of the menstrual cycle(1st menses).

There are 2 types of puberty-

1. Precocious- there is the development of secondary sexual characteristics before the age of 10 years.
2. Delayed- puberty comes after the age of 16 years.

What is the menstrual cycle?

• In the female reproductive system, natural changes occur in a cyclic manner due to the shedding of endometrium through the vagina that makes pregnancy possible.
• The menstrual cycle occurs due to the rise and fall of estrogen levels in females.
• Menses are necessary for the production of oocytes.
• There is a thickening of the lining of the uterus due to the menstrual cycle.
• When there is a thickening of the lining occurs there is the growth of the egg and it is released around the 14th day of the cycle.
• If pregnancy does not occur due to any reason then the lining is released and this is known as menstruation(period).

Criteria for normal menstrual cycle

• The normal menstrual cycle is termed as eumenorrhoea.
• Menarche- 13 years of age.
• Every cycle must repeat in 28-30 days.
• As per year- 13 menses.
• From menarche to menopause(15-45 years), approximately 30 years- 400 menses.
• Blood loss- 20-80 ml.
• Average blood loss- 35ml/menses.
• Bleeding phase- 1-5 days.
• Bleeding duration- 2-7 days.
• Range- 21-35 days.
• The outflow tract must be normal.

Phases of the menstrual cycle(ovarian changes)

1. Ovarian cycle
2. Uterine cycle

Ovarian cycle-

1. Follicular phase
2. Ovulation
3. Luteal phase.

Uterine cycle-

1. Menstruation
2. Proliferative phase
3. Secretory phase.

Ovarian cycle

Follicular phase

• Duration- 14 days.
• The first part of the ovarian cycle.
• When this phase occurs, the ovarian follicles mature and prepare to release an egg.
• Level of FSH(follicle-stimulating hormone)- 3-10mIU/ml.
• A few ovarian follicles are stimulated during the first days of the cycle due to the rise in the follicle-stimulating hormone.
• One dominant follicle in the ovary will mature known as the Graafian follicle and it contains the ovum.
• The development of follicles is known as folliculogenesis.
• At a late stage, it overlaps with the proliferative phase(uterine cycle).

Ovulation

• A second phase of the ovarian cycle.
• In the ovulation phase, the ovarian follicle releases the mature egg into the oviduct.
• FSH acts on follicles which results in the growth of the follicles, and the dominant follicle grows fast and the growing follicle then releases the estrogen which gives negative feedback to the follicle-stimulating hormone and suppresses the FSH, and simultaneously stimulates the luteinizing hormone(LH).
• This process is known as LH surge(starts around the 12th day of the average cycle and it may last up to 48 hours).
• LH works on the Graafian follicle(mature follicle) and the Graafian follicle rupture into pieces(these rupture pieces of Graafian follicle is known as corpus luteum) and results in ovulation(ovum is released).

Luteal phase

• The final phase of the ovarian cycle.
• FSH and LH transform the dominant follicle into the corpus luteum.
• Then progesterone is produced.
• Production of estrogen is induced by the increased progesterone in the adrenal gland.
• FSH and LH production is suppressed by the hormones produced by the corpus luteum.
• It is a phase of 14 days.
• Mainly progesterone is produced by the corpus luteum to maintain pregnancy.
• Up to 15-28 days.
• Falling in the level of progesterone triggers menses and the next cycle begins.

Uterine changes

Bleeding phase/menstruation/catamania

• The first phase of the uterine cycle.
• Usually 1-5 days.
• Heavy periods- menorrhagia.
• Plasmin is an enzyme that inhibits clotting in the menstrual fluid and this condition will lead to iron deficiency.
• Corpus luteum disappears and estrogen and progesterone level are decreased.
• Dysmenorrhea(severe uterine pain) is felt in felt during menstruation.
• Estrogen works as a vasodilator and helps in vasodilation, when it gets reduced, the uterine artery goes into vasoconstriction.
• Some condition arises such as hypoxia, ischemia, and irreversible necrosis in the uterine endometrium.
• Endometrial cells died and bleeding of the uterine artery starts.
• As blood fillup in the uterus(hematometra), this sensation then goes into the hypothalamus.
• From the hypothalamus, this information goes into the posterior pituitary, and oxytocin hormone is released which contracts the uterus, and outflow of blood occurs.
• This results in menstruation.
• The normal thickness of the endometrium is 5-6mm.
• At the end of the bleeding phase, the thickness remains 1mm.

Proliferative phase

• The second phase of the uterine cycle.
• 6-14 days.
• During the follicular phase, estrogen level increases in the ovary and initiates the formation of a new layer of endometrium in the uterus.
• Uterine endometrium thickness increases up to 2-3 mm.

Secretory phase

• The final phase of the uterine cycle.
• Corpus luteum forms and releases two hormones, one is estrogen(which helps to increase the number of cells-hyperplasia), and progesterone(which helps in increase in the size of the cells-hypertrophy).
• Endometrium thickness in this phase becomes 5-6mm.

Symptoms of menstruation

1. Acne
2. Tenderness in the breasts
3. Tiredness
4. Irritation
5. Mood swings
6. Bloating
7. Pain in the abdomen

Complications

1. Iron deficiency anemia
2. Dysmenorrhea

Hope you all find this helpful for you, if you have any query related to this topic or any other topic then you all are free to contact me via contact us or you can also ask your doubts on the comment box. Thank you! 

Disclaimer for https://physioworldblog.blogspot.com/ If you require any more information or have any questions about our site's disclaimer, please feel free to contact us by email at deepikajoshi12347@gmail.com. Disclaimers for Physioworld's blog All the information on this website - https://physioworldblog.blogspot.com/ - is published in good faith and for general information purpose only. Update Should we update, amend or make any changes to this document, those changes will be prominently posted here.