Unit v physiology of mensturation
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The document discusses the physiology of the menstrual cycle. It begins with an introduction to menstruation and the hypothalamic-pituitary-ovarian axis that regulates the cycle. It then describes the three phases of the ovarian cycle (follicular, ovulatory, luteal) and the corresponding four phases of the uterine cycle (menstrual, proliferative, secretory, ischemic). It also discusses cervical mucus changes, abnormalities in menstruation, and some comfort measures during menstruation.
Unit v physiology of mensturation
- 1. Unit 5 Reproductive system Faculty: Deepa Lashkari Topic Physiology of mensuration
- 2. Outline: • Introduction • Definition • Characteristics of normal menstruation • The hypothalamic-pituitary-ovarian axis • Ovarian cycle • Menstrual cycle • Menstrual abnormalities • Comfort measures during menstruation
- 3. Introduction • Typically, a woman of childbearing age or reproductive age (15-45) should menstruate every 28 days or so unless she's pregnant or moving into menopause. But numerous things can wrong with the normal menstrual cycle. The menstrual cycle is essential for the production of eggs, and for the preparation of the uterusfor pregnancy • Note The flow of menses normally serves as a sign that a woman has not become pregnant. (However, this cannot be taken as certainty, as a number of factors can cause bleeding during pregnancy
- 4. Definition: Menstruation means cyclic uterine bleeding caused by shedding of progestational endometrium it occurs between menarche & menopause Menstruation (also called menstrual bleeding, menses, or aperiod)
- 5. Characteristicsof normal menstruation • Menarche: 10-16years. average 13years. • Duration: 2-7 days (<2days is hypomenorrhea & >7 days is menorrhagia • Amount: 30-80ml.,uses 3 napkins per day, >80 ml. is menorrhagia & < 30 ml. is hypomenorrhea. Note: Factors such as heredity, diet and overall health can accelerate or delay menarche:length variation between eight and 20 days in a woman is considered as moderately irregular menstrual cycles. Variation of 21 days or more is considered very irregular
- 6. • 4-Normally menstrual blood doesn’t coagulate as a result of secretion of fibrinolysin enzyme (plasmin) secreted by the endometrium. 5-Menstrual molimina refers to mild symptoms of 7-10 days before mensutration relieved once mensuration occurs exaggrerated condition called premenstrual syndrome.
- 7. Thehypothalamic-pituitary- ovarian axis: • There Are two main components of the menstrual cycle, the changes that happen in the ovaries in response to pituitary hormones (the ovarian cycle) • & the variations that take place in the uterus,but it is important to remember that both cycles work together simultaneously to produce the menstrual cycle. • Changes in cervical mucus also take place during the course of the menstrual cycle.
- 9. OvarianCycle: The ovarian cycle refers to Periodic changes that occur in the ovary every month during the ♀ reproductive life. Cyclical changes in the ovaries occur in response to two anterior pituitary hormones: Follicle-stimulating hormone(FSH) Luteinizing hormone (LH).
- 10. • Fetus:6-7 million in 20 wks. • At birth:1-2 million • At puberty:300,000 • Release during ovulation:400- 500 • At menopause: rare Ovarian follicular development
- 11. The changes that occur in the ovary during each cycle canbe divided into three phases: 1)Follicular phase (day 1-13) 2) Ovulatory phase(day13-15)** 3) The luteal phase (day15-28). These phases run in parallel with the phases of the uterine cycle and together comprise the menstrual cycle.
- 13. • At the beginning of each menstrual cycle, the hypothalamus secretes -----< GnRh in a pulsatile manner to stimulate ----< ant. Pit. gland to secretes ------< FSH &LH. FSH is responsible for the growth of several primaryfollicle The follicular phase iscontrolled by FSH, encompasses days 1to 13of a 28-daycycle.
- 14. • only one follicle on one of the ovaries reaches maturity (graafian follicle) which secretes oestrogen. Estrogen has negative feedback on the pituitary to stop FSH Estrogen causes the uterine lining (endometrium) to grow thicker
- 16. • The estrogen peak stimulates secretion of LH. The LH peak leads to : • The follicle to burst open, releasing the mature ovum into the abdominal cavity a process called ovulation. & corpus luteum formation. • Ovulation occurs on 14 day of 28-day cycle. • Note: High estrogen also suppress FSH secretion so no further follicles grow
- 17. 3-Luteal phase:
- 18. • After ovulation, LH levels remain elevated & cause the remnants of the follicle to develop into a yellow body called the corpus luteum. • In addition to producing oestrogen, the corpus luteum secretes a hormone called progesterone.
- 19. • when progesterone reaches a high level it inhibits the secretion of LH leads degeneration of the corpous luteum (If fertilization does not take place),and so oestrogen and progesterone drop & separation of the endometrium (menstruation) & stimulates the hypothalamus to secrete more GnRH, a new cycle is started.
- 21. II -UterineCycle: • The uterine cycle refers to the changes that are found in the uterine lining of the uterus. These changes come about in response to the ovarian hormones estrogen and progesterone. There are 4 four phases to this cycle: • Menstrual, • Proliferative, • Secretory & • Ischemic.
- 22. 1-Menstrual Phase • Day 1 of the menstrual cycle is marked by the onset of menstruation. • During the menstrual phase of the uterine cycle, the uterine lining is shed because of low levels of progesterone &estrogen. • At the same time, a follicle is beginning to develop and starts producing. • The menstrual phase ends when the menstrual period stops on approximately day 5. • Duration: 1-5days
- 23. 2-Proliferative Phase • When estrogen levels are high enough, the endometrium begins to regenerate. • Estrogen stimulates blood vessels to develop. The blood vessels in turn bring nutrients and oxygen to the uterine lining, and it begins to grow and become thicker. • The proliferative phase ends with ovulation on day 14.
- 24. 3-SecretoryPhase • After ovulation, the corpus luteum begins to produce progesterone. This hormone causes the uterine lining to become rich in nutrients in preparation for pregnancy. • Estrogen levels also remain high so that the lining is maintained. • If pregnancy doesn’t occur, the corpus luteum gradually degenerates, & the woman enters the ischemic phase of the menstrual cycle.
- 25. 4-IschemicPhase. • On days 27 & 28, estrogen and progesterone levels fall because the corpus luteum is no longer producing them. • Without these hormones to maintain the blood vessel network, the uterine lining becomes ischemic. • When the lining start slough, the woman has come full cycle and is once again at day 1of the menstrual cycle.
- 27. CervicalMucus Changes: • Changes in cervical mucus takes place over the course of the menstrual cycle. • Some women use these characteristics. To help determine when ovulation is likely To happen. • During the menstrual phase the cervix doesn’t produce mucus. • As the prolipherative phase begins, the cervix begins to produce a tacky, crumbly type of mucus that is yellow orwhite.
- 28. • As the time of ovulation becomes near, the mucus becomes progressively clear, thin and lubricative, with the properties of raw egg white. At the peak of fertility(i.e., during ovulation), the mucus has a distensible, stretchable called spinbarkheit. After ovulation the mucus becomes scanty, thick, and opaque.
- 30. Fig. 34-1: Events of the Menstrual Cycle Hypothalamus secretes GnRH Anterior pituitary secretes LH and FSH Graafian follicle stimulated Ovaries release estrogen High estrogen levels inhibit FSH secretion, stimulate LH production LH makes mature follicle burst: ovulation LH makes corpus luteum secrete progesterone Progesterone inhibits LH secretion Decreased LH and FSH levels Corpus luteum atrophies, stops making progesterone Decreased estrogen and progesterone levels stimulate GnRH secretion FollicularstageLutealstage ProliferativephaseSecretoryphaseMenstrual phase
- 31. • Anovulation • Hypomenorrhea • Metrorrhagia • Oligomenorrhea • Amenorrhea • Polymenorrhea CYCLE ABNORMALITIES
- 32. Term Description Amenorrhea No periods Dysmenorrhea Painful periods Hypomenorrhea Regular menstruation occurring at normal intervals, but with minimal blood loss. Menorrhagia, hypermenorrhea or Regular menstruation occurring at normal intervals, but with heavy blood loss. Menometrorrhagia Prolonged bleeding that occurs at irregular intervals Menometrorrhagia (meno = prolonged, metro = short, rrhagia = excessive flow/discharge). Metrorrhagia Bleeding that occurs at frequent, irregular intervals(spotting) Oligomenorrhea Abnormal prolongation of the intermenstrual period, every five weeks or more. Polymenorrhea Regular menstruation, which is normal in amount but it, occurs at short intervals, three weeks or less. Postmenopausal bleeding Bleeding that occurs after menopause. syndromePremenstrual (PMS) Physical and psychological symptoms that occur before the start of a period. Primary amenorrhea No periods ever starting (at puberty). Secondary amenorrhea Periods that has stopped.
- 33. Carecomfortmeasuresduring menstruation Menstrual hygiene: 1-Sanitary pads and tampons: • Wash hands before & after giving self-perineal care. • Washing or wiping the perineium should be always done from front to back. • Reduce use of tampons by substituting sanitary pads especially at night. • Use tampon only for heavy menstrual flow.
- 34. 2- Vaginal spray anddouching: • Spray should be used externally only not with pads. • Should not be applied with broken irritated or itched skin. • Douching washes away the natural mucus and upsets the vaginal ecology, thus make it liable to infection.