The document summarizes the major human body systems and how they work. It discusses the digestive system, skeletal system, circulatory system, muscular system, nervous system, and respiratory system. For each system it describes the main organs and their functions in transporting, protecting, and supporting the tissues and cells of the body.

1. The Human Body Systems

2. The Body Systems
Everyone is different. We have different
skin colors, hair colors, body shapes and
sizes — but we all look alike inside. If you
could peek inside your own body, what
would you see? Hundreds of bones, miles
of blood vessels, and trillions of cells, all of
which are constantly working together,
doing all kinds of different things.

3. The Human Body Systems Work Together
 The Digestive System
 The Skeletal System
 The Circulatory System
 The Muscular System
 The Nervous System
 The Respiratory System

4. The Digestive System

5. The Digestive Tract

6. First Organs of the Digestive Tract
 The mouth and teeth are
the first organs of the
digestive tract.
 The teeth are bones
whose main purpose is to
grind food into bits that the
body can digest.
 Saliva helps begin to
break down food.

7. The Esophagus
 The esophagus runs from the pharynx to
the stomach.
 The esophagus is about 25 cm ( 10
inches) long.
 The esophagus is really a large muscle
which pushes food down to the stomach.

8. The Stomach
 The stomach is a J- shaped muscle.
 The stomach acts as a churn.
 Chemical breakdown of food begins in the
stomach.

9. The Small Intestine
 The small intestine is the main organ of the of the
digestive tract.
 The small intestine absorbs processed food into
the bloodstream to deliver to the cells. The
unabsorbed food then passes to the large
intestine.

10. The Large Intestine
.
 The large intestine is about 5 feet long.
 The main job of the large intestine is absorb
water and to get rid of unwanted materials.

11. The Skeletal System
The Skeletal System is made up
of bones, ligaments, and tendons.

12. Function of the Skeletal System
 Protects our vital organs
such as the brain, the heart,
and the lungs.
 Gives us the shape that we
have. Without it, we would
just be a blob of blood and
tissue on the floor.
 Allows us to move. Because
our muscles are attached to
our bones, when our
muscles move, they move
the bones, and we move.

13. How Bones Work
Our bones don't work on their own. The
bones join together to form joints. The end
of each bone is covered by a tough,
smooth shiny substance called cartilage
that works like oil in a car. All of this is so
your bones won't scratch and bump
against each other when you move. Our
bones are held together by strong stretchy
bands called ligaments.

14. Interesting Facts
 The smallest bones in the body are found in the ear.
 The longest bone in the body is the femur.
 The bones are filled with something called bone marrow
which makes red and white blood cells.
 Over half the body's bones are in the hands and feet.
 The only joint-less bone in your body is the hyoid bone in
your throat.
 As your bones grow, you get taller.
 When you were born, your skeleton had around 350 bones.
By the time you become an adult, you will only have around
206 bones. This is because, as you grow, some of the bones
join together to form one bone.

15. The Circulatory System

16. Circulatory System
 The circulatory system
consists of the heart,
blood vessels, and
blood.
 The heart is a muscular
organ about the size of a
fist.
 It beats about 70 to 90
times a minute, pumping
blood though the blood
vessels.

17. The Heart
The heart has two
sides, right and left,
separated by a thick
muscular wall. Each
side has two
chambers.

18. The Muscular System
There are more than 600 muscles in the human body.

19. The Function of Muscles
 Muscles help you do almost
everything — from pumping
blood throughout your body
to lifting heavy objects.
 You control some of your
muscles, and others, like
your heart, do their jobs
without you thinking about
them at all.

20. How Muscles Work
 Muscles work in a very simple way. All
they do is tighten up--that is, contract--
and relax.
 You have two sets of muscles attached
to many of your bones which allow them
to move.
 Muscles can only pull. They never push.

21. The Nervous System
The main parts of the Nervous
System are the Brain, the Nerves,
and the Spinal Cord.

22. The Nervous System
 The spinal cord is the main pathway for
information connecting the brain and
peripheral nervous system.
 The human spinal cord is protected by
the bony spinal column.
 The spinal column is made up of bones
called vertebrae.

23. Nerves
 All through our body there are nerves which
connect to the spinal cord.
 This is called the nervous system. Messages
from the nerves travel to the spinal cord, which
sends them to the brain.
 The brain works out what the messages are so
we know what we are seeing, touching, hearing,
and tasting, and if something hurts or feels.

24. The Spinal Cord
We each have a backbone, called a spine.
Inside it there is a spinal cord. The spinal
cord joins the brain at the top of our neck. Its
main function is to serve as a pathway for
the messages from the nerves to travel to
the brain and back so we know what we are
seeing, touching, hearing, and tasting, and if
something hurts or feels.

25. The Brain
 Inside our head is the brain. It controls
how our bodies work and is protected by
the a thick bone called the skull.
 The brain makes sure our hearts keep
beating and our lungs keep working
without us having to think about it.
 Part of the brain makes our muscles work.
 The biggest part of the brain makes us
think, see, hear, feel and taste.

26. Respiratory System

27. Function of the Respiratory System
 The primary function of
the respiratory system
is to supply the blood
with oxygen in order for
the blood to deliver
oxygen to all parts of the
body.
 The main parts of the
Respiratory System are
the Nose, Mouth, Lungs,
Trachea, Diaphragm.

28. When you Breathe
Did you know that
when you breath, air
goes through your
Respiratory System?
The Respiratory
System is made up of
your nose, throat,
trachea, and lungs.

29. Take Care of Your Respiratory System!
 Don’t smoke.
Smoking damages
your Respiratory
System.
 Exercise to
strengthen your
breathing muscles.
 If you ever have
trouble breathing, tell
an adult at once.

30. Smoking Damages Your Lungs
Do you smoke?
If you smoke this is
what your lungs will
look like.
If you don't smoke this
is what your lungs will
look like.