The Body Systems are ranked in order of importance.....

2.  * Your cells are the basic living units that
make up your body.
 *Groups of cells come together to form
specialized tissues.
 * Groups of tissues come together to form your
organs.
 * Organ systems – groups of organs that
perform a specific purpose in the human body.

3.  Here are the body systems in order of importance:
 Nervous System
 Endocrine System
 Cardiovascular System
 Respiratory System
 Digestive System
 Urinary System
 Muscular System
 Skeletal System
 Integumentary (Skin) System
 Immune System (includes Lymphatic System)
 Reproductive System

4.  These two systems are co-directors of ALL of your body’s
moment-to-moment activities.
The Nervous System is made up of the brain, the spinal
cord, and nerves. One of the MOST important systems in
your body, the N.S. is your body’s control system. It sends,
receives, and processes nerve impulses throughout the
body, which tell your organs and muscles what to do and
how to respond to the environment. The most important
system is Autonomic N.S. which regulates involuntary
action, such as HEART BEAT and digestion.
 The Endocrine System is made up of a group of glands that
produce the body’s long-distance messengers, or hormones,
which control body functions, such as metabolism, growth,
and sexual development..

7.  Your Respiratory
System brings in the
oxygen that your
Cardiovascular
system delivers to all
of your calls. Your
Respiratory System
also plays a vital role
in maintaining your
blood pH.

8.  Your Digestive System provides fuel for all of your
other organ systems to use to produce energy.
 Your Urinary System is essential to maintaining fluid
and pH balance within all of your organ systems.

9.  Your Muscular System allows you to move (making
the rest of your organ system relevant to your
existence). It also serves as an important reservoir for
your Endocrine System.
 Your Skeletal System provides physical protection and
structural support for your other organ systems.
 Your Integumentary (skin) and Immune Systems
play critical roles in preventing life-threatening
infections of all of your other organ systems.
 Your Reproductive System is a system of organs
within an organism which work together for the
purpose of reproduction.

10.  These systems don’t just exist as individual units. The final
product of these cooperating system is one unit called THE
BODY. Each system depends on the others, either directly
or indirectly, to keep the body functioning normally.
 Each of your organ systems are groups of organs that work
TOGETHER to carry out specific duties in your body.
 Some organs contribute essential work to MORE than ONE
organ systems.
 Finally, it’s important to point out that ALL of your organ
systems AFFECT one another.

11.  The Nervous System is one of the most important systems
in your body, because it your body’s central system. There
are 3 parts of your N.S. that work together:
 1. The central N.S. which consists of the brain and spinal
cord. It sends impulses and analyzes information from the
sense organs, which tell your brain about things you see,
hear, smell, taste and feel.
 2. The peripheral N.S. which includes the craniospinal
nerves that branch off from the brain and the spinal cord. It
carries the nerve impulses from the central N.S. to the
muscles and glands.
 3. The autonomic N.S. which regulates involuntary action,
such as HEART BEAT and digestion.

12. All systems are vital to our survival, but if I have to pick the most
important ones, I would go with The Nervous and the Cardiovascular
Systems.
The Circulatory System is our body’s transport system, which is made up
of the vessels and the muscles that help and control the flow of the blood
around the body. Then the heart pumps the blood and the arteries and
veins transport it.
 So the reason why I picked the Nervous System on the first place is
because as I mentioned before the Autonomic N.S. performs the very
important function such as a HEART BEAT. And the Peripheral N.S.
carries the nerve impulses from the Central N.S. to the muscles (which
also control the flow of the blood around the body) and glands. So if the
N.S. wont send the nerve impulses to the muscles, they wont be able to
help to control the blood flow.
 And as we all know that if the heart fails/stops working , we go to
HEAVEN 
Least important would be the Reproductive System, because we can
survive and live a full life without it- although if no one had one, the
species would die out !!!!