Download The Reproductive System

The Reproductive
System
Objective 3.4
Function of the Reproductive
System
The reproductive
system allows for
the production of
offspring and the
continuation of
life.
Sexual vs. Asexual
• Sexual reproduction brings together
genetic material from two parents. There
is a greater amount of variation among
animals that reproduce sexually.
• Asexual reproduction only involves one
parent and the offspring produced are
identical to the parent.
Sexual reproduction
An egg is the female sex cell, and a sperm
is the male sex cell.
The joining of a sperm and egg is called
fertilization.
A fertilized egg is called a zygote.
The young organism that develops from
the zygote is called the embryo.
External vs. Internal fertilization
External fertilization is when the eggs are
fertilized outside of the female’s body.
The male spreads a cloud of sperm cells
over the eggs. Most fish reproduce this
way.
Internal fertilization is when the eggs are
fertilized inside the female’s body.
The Male Reproductive System
The function of the male reproductive
system is to produce sperm.
The main male sex hormone is
testosterone. This hormone
regulates the production of sex cells
and male characteristics such as
facial and chest hair.
Sperm production
The oval shaped testes are the
organs where sperm are produced.
Sperm are produced in the
seminiferous tubules in each testis.
They are then stored in the
epididymis to mature.
The path of sperm
Once sperm cells form in the testes,
they travel through the vas deferens
and mix with other fluids produced by
nearby glands. This mixture is called
semen.
The penis transfers the semen to the
female during intercourse.
The Male Anatomy
The Female Reproductive System
The function of the female reproductive system
is to produce eggs, nurture fertilized eggs, and
give birth.
The ovaries produce eggs and sex hormones,
such as estrogen and progesterone.
The sex hormones regulate the production and
release of eggs. The sex hormones also control
the development of female characteristics such
as breasts.
The Path of the Egg Cell
Eggs are produced and mature inside the
ovaries.
After puberty, eggs are released from the
ovary once a month during ovulation.
The egg then enters the fallopian tube,
where it has potential to be fertilized. If it
is not fertilized, the female will release the
uteran build up during mentruation.
The Female Anatomy
The Menstrual Cycle
During the menstrual cycle, an egg develops in
an ovary. At the same time, the uterus prepares
for the arrival of an embryo.
Once the egg is released, it can be fertilized for
the next few days. If the egg is not fertilized, it
breaks down. The lining of the uterus also
breaks down. The extra blood and tissue from
the thickened lining of the uterus pass out of the
body through the vagina.
The 28-Day Cycle
Conception
When the egg is fertilized in the
fallopian tube, it is called a zygote.
The cells of the zygote continue to
divide and travel to the uterus.
When the zygote enters the uterus, it
implants in the lining. It is then called
an embryo.
The embryo
In order to survive, the embryo is fed
nutrient-rich blood through an
umbilical cord. The cord is attached
to the placenta.
The placenta is a rich network of
blood vessels attached to the wall of
the uterus. It delivers nutrients and
oxygen to the baby and gets rid of
waste products.