The menstrual cycle 15.02.2021

The menstrual cycle

1. THE MENSTRUAL CYCLE presented By Mustafa Samir aljaroudi Mohammad Alziyadi Mohammad alali

2. Overview: The menstrual cycle starts on the first day of the menstrual period, and ends with the start of the following period.  It is made up of four phases, during which hormones change to prepare women for pregnancy each month.  It is natural to experience some discomfort during the menstrual cycle There are several methods and guidelines to relieve pain before and during a menstrual period.

3. Structure of the female reproductive system The vagina :  A canal connecting between the uterus and the external reproductive organs .   The uterus :  A hallow pear-shaped organ where the fetus grows during pregnancy. It is separated from the vagina by a narrow canal called: the cervix

4. Fallopian tubes :  Narrow canals connected to the upper part of the uterus. Through them, the eggs travel from the ovaries to the uterus, and inside them, the egg meets the sperm (fertilization). Then, the fertilized egg travels through the tubes to the uterus where it can stick to the uterine wall and form an embryo.  Ovaries :  Small oval-shaped glands located on the sides of the uterus. Eggs form inside the ovaries that also produce female hormones

5. Menstrual cycle A menstrual cycle consists of natural changes that occur in a woman’s body every month in preparation for pregnancy Menstruation starts at puberty and ends at menopause . The cycle lasts an average of 28 days but may vary between 20 and 40 days. The first day of a cycle is the first day of a menstrual period and the last day is that of the following period

6. First menstrual period The menstrual cycle often begins at puberty between the ages of 8 and 15 (average age of 12). It usually starts two years after breasts and pubic hair start to develop. 

7. Menstrual cycle phases The menstrual cycle consists of four phases: 1-Menstruation. 2- the follicular phase. 3-Ovulation. 4-luteal phase.

8. Menstruation Menstruation is the vaginal discharge of the internal lining of the uterine wall, along with other secretions from the body. It usually lasts three to seven days but this could change to more or less days from month to month and depending on each woman

9. Hormone Control of Cycle Cycle controlled by hypothalamus, however this can be influenced by higher centers within the brain i.e. due to stress or anxiety Hypothalamus releases gonadotrophin-releasing hormone in pulsatile manner  anterior pituitary  release of LH and FSH

10. Follicular stimulating hormone ( FSH ) – glycoprotein Stimulates follicular maturation during follicular phase Stimulates steroid hormone secretion – oestrogen Luteinizing Hormone (LH) – glycoprotein Stimulates steroid hormone secretion – oestrogen Ovulation – mid-cycle surge of LH Progesterone production by corpus luteum

11. Follicular Phase T he follicular phase starts on the first day of menstruation and ends with ovulation pituitary gland (situated at the base of the brain) releases a follicle stimulating hormone. This hormone produces 10 to 20 follicles in the ovary and each follicle houses an immature egg

12. Days 1-8 FSH and LH relatively high levels Stimulate development of 10-20 follicles Results in full maturation of a single dominant follicle – appearing in mid- follicular phase Remainder undergo atresia Oestrogen levels start to rise as follicular development occurs

13. Days 9-14 Follicle increases in size Transforming primary follicle to secondary follicle Rise in oestrogen by granulosa cells, associated with follicular maturation Inhibin produced by granulosa cells restricting number of follicles maturing

14. Ovulation Day 14 rapid enlargement of follicle and rupture of the follicle with extrusion of the oocyte Rise in oestrogen  mid-cycle surge of LH and to a lesser extent FSH  ovulation Immediately before ovulation there is a drop in oestrogen and an increase in progesterone Ovulation follows within 18 hours of mid- cycle surge of LH If not enough of a LH surge – then no ovulation occurs – anovulatory

15. Luteal Phase Days 15-28 remainder of the follicle retained in the ovary corpus luteum formation -the major source of sex hormones- oestrogen and progesterone This leads to marked increase in progesterone and estrogen

16. If conception and implantation occur: Corpus luteum doesn’t regress – maintained by gonadotrophins secreted by trophoblasts If conception doesn’t occur successfully: Corpus luteum regresses and menstruation occurs Drops in steroid sex hormones  leads to a rise in gonadotrophin levels (FH and LSH)  initiate next cycle

17. Common issues accompanying the menstrual cycle Cramps : Many women experience stomach spasms during the first few days of their cycle. They occur because of chemicals in the body that cause the uterine muscles to contract to help shed the uterine lining. 

18. Dysmenorrhea (painful periods) It is the most common menstruation problem. The pain varies from one woman to the other. There are two types of dysmenorrhea

19. Primary dysmenorrhea : It is a very common condition that occurs because of the contraction in uterine muscles. It typically occurs during adolescence and fades away with age. Started menstruating before the age of 11 Have heavy and long periods;

20. Secondary dysmenorrhea : It is the pain resulting from physical problems. The pain becomes worse with age The most common health issues that may cause it are: - Endometriosis; - Uterine fibroids. - Ovarian cysts.

21. Excessive bleeding : Excessive bleeding may occur due to the following causes: Ovulation issues: An imbalance of hormones during ovulation may lead to the excessive formation of an internal uterine lining, which in turn increases the amount of blood shed during menstruation. Thyroid disorders Uterine fibroids: They are muscle tissues that form on the uterine wall and are usually benign. 

22. Benign tumors Some medications Problems conceiving (e.g. miscarriage, ectopic pregnancy) Bleeding disorders (e.g. haemophilia ) Obesity Use of an intrauterine device (IUD)

23. Summary The menstrual cycle is complex and controlled by many different glands and the hormones that these glands produce The four phases of the menstrual cycle are menstruation, the follicular phase, ovulation and the luteal phase .

24. Summary Common menstrual problems include heavy or painful periods and premenstrual syndrome (PMS). Knowing when in the menstrual cycle a woman is most likely to conceive can increase the chance of pregnancy.

25. Reference: https://www.moh.gov.sa/en/HealthAwareness/EducationalContent/wh/Pages/012.aspx Oxford Handbook of Obstetrics and Gynecology 3rd Edition

26. Thank you