The Story of Village Palampur Class 9 Free Study Material PDF
Menstrual cycle
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4. • Definition: The reproductive cycle in the female primates (e.g.
monkeys, apes and human beings) is called menstrual cycle.
• Menarche: Beginning of menstruation at puberty.
• Menopause: Menstrual cycles ceases around 50 years of age;
that is termed as menopause.
• Menstrual Cycle: The cycle of events starting from one
menstruation till the next one is called the menstrual cycle.
• Average Days: In human females, menstruation is repeated at
an average interval of about 28/29 days.
5.
6. (1) Menstrual Phase:
i. In a 28 days menstrual cycle,the menses takes place on cycle
days
ii. The production of from the anterior lobe of the pituitary gland
is
iii. The withdrawal of this hormone causes
and, therefore .
iv. The of uterus
v. The
constitutes the menstrual flow.
(2) Follicular Phase:
i. This phase usually includes cycle days in a 28 days
cycle.
ii. The (FSH) secreted by the anterior
lobe of the pituitary gland stimulates the
.
iii. Estrogen stimulates the of the
uterine wall.
iv. The by rapid cell multiplication and
this is accompanied by an
.
7. (3) Ovulatory Phase:
i. Both in the middle of
cycle (about 14th day).
concentration in blood
iii. Rapid secretion of induces
iv. In fact .
(4) Luteal Phase:
i. Includes cycle days
ii. The ovulation (ovulatory phase) is followed by the
luteal phase during which the remaining parts of the
iii. The secretes large amounts of
which is essential for
. Such an endometrium is necessary
for implantation of the fertilized ovum and other
events of pregnancy
iv. Uterine glands become secretory.