Biology today

to respond or may be resistant to FSh. In this case FSh

levels are very high and the estrogen level very low. It

occurs between 45 to 55 years (In some individuals it is

between 40 to 50 years).

Table : Phases of menstrual cycle

Phases Days Events

menstrual

phase

1 st-5th Endometrium breaks down,

menstruation begins. The cells of

endometrium, secretions, blood and

the unfertilised ovum constitute

the menstrual flow. Progesterone

production is reduced.

Follicular

phase

(Proliferative

phase)

6 th-13th Endometrium rebuilds, FSh

secretion and estrogen’s secretion

increase.

Ovulatory

phase

14 th Both Lh and FSh attain a peak

level. concentration of estrogen in

the blood is also high and reaches

its peak. Ovulation occurs.

Luteal phase

(Secretory

phase)

15 th-28th corpus luteum secretes

progesterone. Endometrium

thickens and uterine glands

become secretory.

• Since there are no developing follicles, the supply of
estrogen and progesterone is reduced. This may lead to
temporary depression, hot flushes and other physiological
and psychological problems in menopause.

•    Other common symptoms are fatigue, vaginal dryness and

softening of bones due to loss of minerals particularly

calcium.

Fig.:Female’s fertility

Optimal

fertility

End of

fertility

Irregular

cycles

0 18 5145413731

Age (yrs)

Menopause

1,000

10,000

100,000

1,000,000

Follicle

number

Birth

Decreased

fertility

•    menstrual cycle is controlled by FSH, LH, estrogen and

progesterone.

•    Dysmenorrhoea is painful menses.

•    Menorrhagia is excessive menstruation.

•    Oligomenorrhoea is sparse or infrequent menstruation.

•    Amenorrhoea is non-occurrence of menses.

•    Oestrus cycle is a series of cyclic changes that are found

in the ovaries, reproductive tract and hormones of female

nonprimate mammals, e.g., cows, dogs, cats, horse,

buffalo. During this period the female receives the male.

at the end of oestrus, the lining of reproductive tract

is sloughed off. however, there is no menstruation. The

sloughed off tissues are absorbed. Oestrus is followed by

a passive period called anoestrus.

Infertility in women is the inability to become pregnant.

It may be due to failure to ovulate or to some

anatomical factor that prevents the union of egg and

sperm.

It is inflammation of ovary, usually caused by an infection.

Oophoritis

It is implantation of embryo ataplace other

than uterus, generally in the oviduct.

Ectopic pregnancy

Ovarian cysts are fluid filled tumours of the ovary. Such

cysts sometimes rupture and regress (get smaller)

during pregnancy.

Oophorocystosis (Ovarian cysts)

It is relatively slow-growing cancer. Its main risk is that it is

unnoticed until it has invaded other tissues.

Cervical cancer

It is the growth of endometrial tissue outside the

uterus. Symptoms include premenstrual pain or

unusual menstrual pain.

Endometriosis

Infertility

Breast cancer is rarely seen before the age of thirty. Its

incidence increases after menopause.

Breast cancer

Disorders of female

reproductive system

4. Why children born to older women have high chances of chromosomal abnormality?


5. What is the role of granulosa cells in female reproductive system?