2. ABOUT…..
› Cyclical event in which there is periodic shedding of uterine endometrium
followed by its proliferation & preparation for implantation.
› Derived from “MENSEM - a month”
› Characteristic of primates (humans, apes & monkeys)
› Other vertebrates –Estrous cycle
› Menarche – beginning of menstrual cycle (11-13yrs)
› Menopause - cessation of menstrual cycle (45-52yrs)
3. DURATION OF MENSTRUAL CYCLE
› Length of cycle average about 28 days.
› Is not same in women.
› Normally, it ranges from 21 to 35 days.
› Cycle becomes irregular towards menopause.
› Irregularities indicates dysfunctions of reproductive system.
› Physiologically, MC temporarily ceases during pregnancy & lactation.
10. Uterine cycle Menstrual phase Menstruation
Decreased blood in
endometrial tissue causes
tissue to die & slough into
vagina
Menstrual flowProliferative phase
Uterus prepares for the
fertilised ovum
1.Endometrial lining develops
2.Endo.layer grows
3.Endo.glands enlarge
4.smooth muscle layer thickens
5.cervical glands secrete mucus
Secretory phase
Endometrium prepares for
implantation
1. ↑ blood supply
2.Enlarrged glands that
secrete glycogen fluid
3.Cervical secretions
If fertilization does not
occur, corpus luteum
degenerates
Follicular phase begins
again.
Estrogen levels
causes
11.
12. CHANGES IN REPRODUCTIVE ORGANS IN
MENSTRUAL CYCLE
Changes in follicular phase (Menstrual & Proliferative phase)
1.Ovarian changes
One follicle is selected as dominant follicle (4th day).
Dominant follicle → mature follicle.
Granulosa & theca interna cells proliferate &secrete Estrogen.
Follicle ruptures about 14th day resulting in ovulation.
2.Uterine changes
Layers of uterine endometrium are sloughed.
Thickness of endometrium ↑ from 5th day to 14th day –influence of Estrogen.
Endometrial glands lengthen & glands are drawn out.
Formation of no.of spiral arteries.
Proliferation of endometrium –main feature (preovulatory phase).
13. 3.Uterine cervix changes
Volume of cervical mucus ↑.
Alkalinity & elasticity ↑.
Cervical epithelium becomes more secretory.
Forms spinnbarkeit.
4.Vaginal changes
Vaginal epithelial cells become keratinized
14. Changes in the luteal phase (Secretory phase)
1.Ovarian changes
Follicle is rapidly filled with blood – corpus hemorrhagicum
Granulosa & theca cells –lutenization →lutein cells →corpus luteum
If pregnancy does not occur, it degenerates b/w 26th -28th days –corpus albicans
15. 2.Uterine changes
Progesterone secretion ↑
Estrogen also ↑ to an extent.
Uterine glands become coiled &tortuous.
Glandular cells store glycogen & secrete large quantity of carbohydrate –rich
mucous &fluid.
Vascularity of endometrium ↑.Spiral arteries become tortuous.
3.Changes in cervical mucous
Cervical mucous becomes thick & elasticity ↓.
Sperm cannot enter through progesterone-dominant cervical mucous.
4.Vaginal changes
Vaginal epithelium proliferates & secretes thick mucous.
Keratinization ↓
16.
17. DISORDERS OF MENSTRUAL CYCLE
› Amenorrhea :absence of menstrual cycle.
› Anovulation : absence of ovulation during a menstrual cycle.
› Hypomenorrhea : ↓ menstrual bleeding in duration or amount or both.
› Oligomenorrhea : ↓ frequency (cycle more than 35 days) of MC.
› Dysmenorrhea : Painful menstrual bleeding.
› Menorrhagia : ↑ menstrual bleeding in amount, duration or both.
› Metrorrhagia : Bleeding occurring between the periods.
› Polymenorrhea : MC occurs frequently (<21 days).
› Premenstrual syndrome :development of nonspecific features about a week
before the onset of menstrual bleeding.
› Anorexia nervosa : complex behavioural disorder in women associated with
functional abnormalities.