Human Reproduction Female Reproduction Systems

Female Sexual Characteristics Female puberty usually begins around the age of 10 – 12 (so on average

about a 1 – 2 before males begin puberty).

During puberty a female will undergo primary and secondary sexual characteristic changes.

Primary sexual characteristics is when the primary organs start to mature.

Secondary sexual characteristics include: growth of underarm hair, pubic hair, and widening of the hips for child birth.

Female Sexual Characteristics Unlike a male – who does not start to produce his sperm until puberty –

females have all their sex cells at birth.

A female can be born with approximately two million eggs, but will have only about 400,000 at puberty.

Once sexual maturity is reached during puberty a single egg matures and will be released each month.

Female Sexual Characteristics The primary female reproductive organ is the ovary, this is where the egg

cells mature and are released from.

Females have two ovaries located in the lower portion of the abdominal cavity one on either side of their sex organ.

Inside the ovaries are follicles, each follicle contains a single immature egg. The follicles contain cells that nourish and protect the developing egg.

Females are able to produce their own hormones – estrogen and progesterone – in the ovaries.

Menstrual Cycle/Path of the Egg A women goes through a menstrual cycle, each cycle is typically 28 days.

The length of a women’s cycle can change the older they get. It can also change if one women lives with other females (for example in a dorm). This is known as the McClintock synchronization theory.

When a female reaches the age of 40 she goes through menopause and this is when she tends to stop producing mature eggs.

Menstrual Cycle/Path of the Egg Menstruation is the

shedding of the endometrium (this happens in the first stage)

There are four main stages a female goes through during a menstrual cycle Flow Phase Follicular Phase Ovulation Luteal Phase

Menstrual Cycle/Path of the Egg After an egg is developed and mature it is released from the ovary into the

fallopian tube – usually one egg from one ovary and the next cycle it will release an egg from the other ovary.

The fallopian tube is a tube that allows the egg to get from the ovaries to the uterus.

The lining of the uterus is called the endometrium, it is filled with rich nutrients, blood vessels and mucus that provides nourishment for the embryo.

Menstrual Cycle/Path of the Egg The cervix is a muscle between the vagina and the uterus – it is clamped

relatively shut and only starts to open during child birth.

The vagina has three main functions Receives the male penis and sperm during sexual intercourse; Is the birth canal during delivery of an offspring; and To void the bladder

Menstrual Cycle/Path of the EggPhase Description of Events Hormones

ProducedDays (Approximately)

Flow Phase Endometrium sheds from the female uterus

None 1-5 days

Follicular Phase Follicles in ovaries are being developed and the egg is getting ready to be released

Estrogen is produced

6 – 13 days

Ovulation Egg is released from the ovary

None 14

Luteal Phase Corpus Luteum forms inside the ovary (it is the remains of the pocket that held the egg and the follicle)

Estrogen and Progesterone are produced by the corpus luteum

15 - 28

Menstrual Cycle/Path of the Egg If no sperm is found in the fallopian tube to fertilize the egg, the egg will

make its way to the uterus and expel through the vagina.

If fertilization does occur, it must happen within 24 hours of ovulation (when the egg is released) or the egg degenerates.

The egg moves to the uterus, and once the uterus realizes that the egg is not fertilized, it then sheds the endometrium and starts to prepare for the next cycle.

Then, once the 28th day arrives, the cycle starts all over again.

Pregnancy If the egg is fertilized in the fallopian tube, the two haploids fuse together to

produce a zygote with 23 pairs of chromosomes.

After fertilization, the mass of cells created in the zygote become an embryo.

The Embryo reaches the uterus where it will implant into the endometrium.

During pregnancy the menstrual cycle stops completely while the mother-to-be awaits for the birth of her baby.

Upon the birth of an offspring, females produce a hormone called prolactin. It causes milk to be produced to feed the baby.

Assignment Textbook Pg 116 – Questions 3, 4, 7, 11, 12, 14, 16