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The Reproductive System

Everything you want to know about how humans

grow, develop and reproduce!

What’s the function of the reproductive system?

To make sure the species survives… by passing on your genes…

when you make babies (more humans)!

How does the reproductive system do it? • It produces hormones that control how you

develop (puberty)

• It produces sex cells (egg and sperm cells)

• It transports and sustain these cells

• The female reproductive system nurtures the developing offspring

What is sexual reproduction?

Sexual reproduction just means: the female produces an egg

the male produces sperm

the two sex cells join together during fertilization to produce an offspring.

Most organisms on earth sexually reproduce –plants, insects, animals, humans, etc...

Sexual reproduction makes sure you have a variety of genes – half from EACH parent! Having variety is GOOD for the SPECIES!

The Male Reproductive System

Testes produce: Sperm (sex cells) Testosterone (hormone that

controls sexual maturation in men)

Scrotum: external pouch of

skin that holds the testes (keeps them 2-3°C cooler)

The Male Reproductive System

Sperm mix with fluids from the glands to form semen, which leaves the body through a tube called the urethra in the penis.

Urine also leaves through the urethra, but not at the same time!

The Female Reproductive System

Ovaries produce: Eggs (sex cell) Estrogen

(hormone that controls sexual maturation in women)

Fallopian tubes: carry the eggs to the uterus where a fertilized egg would attach to the wall and develop into an embryo/fetus.

The Female Reproductive System

Unfertilized eggs break down and leave the uterus through the cervix, then exit through the vagina.

The vagina is also called the birth canal (how the baby leaves the mother’s body).

What is puberty? What is puberty?

A period of time when your body changes to become sexually mature (able to reproduce).

When does it happen? Usually begins ages 8-13 for girls; ages 10-

15 for boys, and can last 5-6 years.

What causes puberty? Hormones (chemicals that control your

body’s development) produced by your brain and your ovaries/testes cause your body to change.

Males: Testosterone Females: Estrogen

What happens at puberty?

Physical Changes • Body Size and Shape

Males get taller, broader shoulders Females develop breasts, wider hips,

• Body Hair Underarms, pubic area, facial hair (males)

• Other changes Voice deepens for males Menstrual cycle begins for females

Emotional Changes Feeling moody Sexual feelings

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Now that we know the basics…

How does fertilization happen?

The path of the egg

The path of the sperm

The Human Life Cycle What happens after the egg is

fertilized? The egg is fertilized in the fallopian tubes.

This cell travels for 5 days and divides many times before it enters the uterus.

In the uterus, it attaches to the lining and begins to develop.

The first 2 weeks.

What happens during pregnancy? Pregnancy lasts 38 weeks after conception

(40 weeks after last period).

For the first 8 weeks, the developing human is called an embryo.

After the 9th week until birth, the embryo is called a fetus.

5 weeks 14 weeks 24 weeks

What happens during pregnancy? In 9 months, the fetus grows from a single

cell to a fully formed human baby weighing 7-8 pounds!

Amazing transformations happen as the fetus grows - bones and muscles form, the heart begins to beat, eyes and ears start working….

5 weeks 14 weeks 24 weeks

The Human Life Cycle Protecting and Nourishing the Fetus

Inside the uterus, 2 membranes protect and nourish the baby.

Amniotic Sac – filled with fluid, it cushions the baby.

Placenta – links the mother and fetus. Oxygen & nutrients pass from the mother to baby here.

The umbilical cord links the baby to the placenta.

What happens during birth? The birth of a baby has 3 stages:

Delivery – the baby is pushed out of the

uterus through the vagina and out of the mother’s body.

What happens during birth? The birth of a baby has 3 stages:

Delivery – the baby is pushed out of the uterus through the vagina and out of the mother’s body.

What happens during birth? The birth of a baby has 3 stages:

Delivery – the baby is pushed out of the

uterus through the vagina and out of the mother’s body.

Find out more about the late stages of pregnancy and the

birth process…

The Third Trimester

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Preventing Pregnancy

The only 100% effective way to prevent pregnancy (and protect from sexually transmitted diseases) is to abstain from sex!