short notes on reproductive system of humane female

1. Human female reproductive
system

2. Function of human female
reproductive system
• 1:- is designed to carry out several
functions. It produces the female egg cells
necessary for reproduction, called the ova
or oocytes.
2:-the system is designed to carry the ova
to the sites of fertilization.
3:-the next step after fertilization is to
implant egg into the walls of uterus.

3. • 4:-secrete hormones that maintain female
reproductive system.
5:-external female reproductive system
helps to enable sperms to get within the
body.

4. Formation of female reproductive
system
• Reproductive system consist mainly from
three parts:-
1:-vagina
2:-uterus
3:-fallobian canells
4:-ovaries

5. • Labia major:-The labia majora enclose
and protect the other external reproductive
organs. Literally translated as "large lips,"
the labia majora are relatively large and
fleshy, and are comparable to the scrotum
in males. The labia majora contain sweat
and oil-secreting glands. After puberty, the
labia majora are covered with hair.

6. • Labia mainora:- Literally translated as
"small lips," the labia minora can be very
small or up to 2 inches wide. They lie just
inside the labia majora, and surround the
openings to the vagina (the canal that joins
the lower part of the uterus to the outside of
the body) and urethra (the tube that carries
urine from the bladder to the outside of the
body).

7. • Bartholin`s gland:-These glands are
located beside the vaginal opening and
produce a fluid (mucus) secretion.
Clitoris:-The two labia minora meet at the
clitoris, a small, sensitive protrusion that is
comparable to the penis in males. The
clitoris is covered by a fold of skin, called
the prepuce, which is similar to the
foreskin at the end of the penis. Like the
penis, the clitoris is very sensitive to
stimulation and can become erect.

8. • Vagina:-The vagina is a canal that joins
the cervix (the lower part of uterus) to the
outside of the body. It also is known as the
birth canal.
Uterus:-The uterus is a hollow, pear-
shaped organ that is the home to a
developing fetus. The uterus is divided
into two parts: the cervix, which is the
lower part that opens into the vagina, and
the main body of the uterus, called the
corpus. The corpus can easily expand to
hold a developing baby. A channel
through the cervix allows sperm to enter
and menstrual blood to exit.

9. • Ovaries:-The ovaries are small, oval-
shaped glands that are located on either
side of the uterus. The ovaries produce
eggs and hormones.
Fallobian cannels:-These are narrow
tubes that are attached to the upper part
of the uterus and serve as tunnels for the
ova (egg cells) to travel from the ovaries to
the uterus. Conception, the fertilization of
an egg by a sperm, normally occurs in the
fallopian tubes. The fertilized egg then
moves to the uterus, where it implants into
the lining of the uterine wall.

11. What happened during the
menstural cycle?
• Females of reproductive age experience cycles of
hormonal activity that repeat at about one-month
intervals. With every cycle, a woman's body prepares for
a potential pregnancy, whether or not that is the
woman's intention. The term menstruation refers to the
periodic shedding of the uterine lining. (Menstru means
"monthly.'')
• The average menstrual cycle takes about 28 days and
occurs in phases: the follicular phase, the ovulatory
phase (ovulation), and the luteal phase.
• There are four major hormones (chemicals that stimulate
or regulate the activity of cells or organs) involved in the
menstrual cycle: follicle-stimulating hormone,
luteinizing hormone, estrogen, and progesterone.

12. • Follicular phase of the menstural cycle:-
This phase starts on the first day of your period. During the follicular
phase of the menstrual cycle, the following events occur:
• Two hormones, follicle stimulating hormone (FSH) and luteinizing
hormone (LH), are released from the brain and travel in the blood to
the ovaries.
• The hormones stimulate the growth of about 15 to 20 eggs in the
ovaries, each in its own "shell," called a follicle.
• These hormones (FSH and LH) also trigger an increase in the
production of the female hormone estrogen.
• As estrogen levels rise, like a switch, it turns off the production of
follicle-stimulating hormone. This careful balance of hormones
allows the body to limit the number of follicles that mature.
• As the follicular phase progresses, one follicle in one ovary
becomes dominant and continues to mature. This dominant follicle
suppresses all of the other follicles in the group. As a result, they
stop growing and die. The dominant follicle continues to produce
estrogen.

13. • Ovulatory phase of the menstural cycle:-
The ovulatory phase, or ovulation, starts about 14 days
after the follicular phase started. The ovulatory phase is
the midpoint of the menstrual cycle, with the next
menstrual period starting about two weeks later. During
this phase, the following events occur:The rise in
estrogen from the dominant follicle triggers a surge in the
amount of luteinizing hormone that is produced by
the brain.
• This causes the dominant follicle to release its egg from
the ovary.
• As the egg is released (a process called ovulation), it is
captured by finger-like projections on the end of the
fallopian tubes (fimbriae). The fimbriae sweep the egg
into the tube.
• Also during this phase, there is an increase in the
amount and thickness of mucus produced by the cervix
(lower part of the uterus). If a woman were to have
intercourse during this time, the thick mucus captures
the man's sperm, nourishes it, and helps it to move
towards the egg for fertilization.

14. • Luteal phase of the menstural cycle:-
The luteal phase of the menstrual cycle begins right after
ovulation and involves the following processes:
• Once it releases its egg, the empty follicle develops into
a new structure called the corpus luteum.
• The corpus luteum secretes the hormone progesterone.
Progesterone prepares the uterus for a fertilized egg to
implant.
• If intercourse has taken place and a man's sperm has
fertilized the egg (a process called conception), the
fertilized egg (embryo) will travel through the fallopian
tube to implant in the uterus. The woman is now
considered pregnant.
• If the egg is not fertilized, it passes through the uterus.
Not needed to support a pregnancy, the lining of the
uterus breaks down and sheds, and the next menstrual
period begins.

16. How many eggs does the woman
have?
• The vast majority of the eggs within the
ovaries steadily die, until they are depleted
at menopause. At birth, there are
approximately 1 million to 2 million eggs;
by the time of puberty, only about 300,000
remain. Of these, only about 500 will be
ovulated during a woman's reproductive
lifetime. Any remaining eggs gradually die
out at menopause.

17. Hormones secreted by ovary
• Ovary produce two kinds of hormones:
Estrogen and Progesterone
• Estrogen is a steroid hormone that helps control and
guide female sexual development. Estrogen is
responsible for stimulating the development of female
secondary sex characteristics. We know that secondary
sex characteristics are defined as characteristics specific
to females or males, but not directly related to
reproduction. Therefore, in a female, we see estrogen
helps with such things as development of the breasts,
widening of the hips, and the growth of body hair.

18. • Estrogen works in harmony with progesterone,
which is a steroid hormone that acts to prepare
the uterus to receive the fertilized egg and
maintain pregnancy. While it is correct to say
that progesterone is secreted by the ovaries, it's
more correct to say that it is a hormone
produced by the corpus luteum of the ovaries.
The corpus luteum is a structure that develops in
an ovary after the egg has been discharged.
• So, the corpus luteum is the structure that
remains after ovulation, which is the discharge
of the egg. This structure produces
progesterone for a few days after ovulation and
then degenerates, unless pregnancy occurs. If
pregnancy does occur, the corpus luteum
remains and continues to produce progesterone.

19. • This ensures that the lining of the uterus is maintained,
and not sloughed off, until the placenta is developed
enough to take over progesterone's production. So, we
see that the release of estrogen and progesterone from
the ovaries is needed for reproduction to occur. If these
hormones are under-produced, it will severely impede
the woman's ability to conceive a child.
• As we previously learned, hormones secreted by the
anterior pituitary gland influence the ovaries. As we often
see in our study of the endocrine system, the hormonal
secretions from one endocrine gland stimulate another
endocrine gland to secrete its hormones. This is the
case when we talk about the hormone secreted from the
gonads.

20. • Luteinizing hormone, or LH, is a hormone
from the anterior pituitary that influences
the ovaries and triggers ovulation of the
egg, which leads to the creation of the
corpus luteum. Follicle-stimulating
hormone, or FSH, is a second tropic
hormone from the anterior pituitary that
stimulates production of the egg.

21. Steps of formation of Ova
• In females, the total number of eggs ever to be produced are present in the
newborn female initially arrested at the diplotene stage of the meiosis I from
fetal life through childhood until puberty, when the lutenizing hormone (LH)
surges stimulate the resumption of meiosis.
• All eggs are arrested at an early stage (prophase I) of the first meiotic
division as a primary oocyte (primordial follicle). Following purberty, during
each menstrual cycle, pituitary gonadotrophin stimulates completion
of meiosis 1 the day before ovulation.
• In meiosis 1, a diploid cell becomes 2 haploid (23 chromosomes) daughter
cells, each chromosome has two chromatids. One cell becomes the
secondary oocyte the other cell forms the first polar body.
• The secondary oocyte then commences meiosis 2 which arrests at
metaphase and will not continue without fertilization.
• At fertilization meiosis 2 completes, forming a second polar body. Note that
the first polar body may also undergo this process forming a third polar
body.

22. • The breakdown of the germinal vesicle indicates a
resumption of meiosis and the extrusion of the first polar
body (1 PB) indicates completion of the first meiotic
division in human oocytes. The polar body is a small
cytoplasmic exclusion body formed to enclose the
excess DNA formed during the oocyte (egg) meiosis and
following sperm fertilization. There are 2-3 polar bodies
derived from the oocyte present in the zygote, the
number is dependent upon whether polar body 1 (the
first polar body formed during meiosis 1) divides during
meiosis 2. This exclusion body contains the excess DNA
from the reductive division (the second and third polar
bodies are formed from meiosis 2 at fertilization). These
polar bodies do not contribute to the future genetic
complement of the zygote, embryo or fetus.
• Recent research in some species suggest that the space
formed by the peripheral polar body (between the oocyte
and the zona pellucia) can influence the site of
spermatozoa fertilization.

23. Steps of formation of Ova