Download Levels of Organization

The 6 Levels of Organization of
the Human Body:
The arrangement of specialized
parts within a living thing is
referred to as levels of
organization.
The levels become more complex
as the levels increase.
Organelles—the 1st level of
organization
• Work inside a cell and effect only the
cell
– Examples: mitochondria, nucleus
Cells—the 2nd Level
• Cells are made of organelles.
• Cells are the building blocks of tissues.
• Many cells work together to make up a
tissue.
Cells: LOTS of Different Kinds!
Here are two examples. Can you guess what
kind?
Nerve Cells
Skin Cells
Tissues—the 3rd level
• In any multi-cellular organism, cells rarely work alone.
• Cells that are similar in structure and function are
usually joined together to form tissues.
• Tissues have specialized functions and including
many types including connective, muscle,
epithelial, nerve, bone, etc.
Let’s Look Again…
Here are the cells we saw before, but if you look closely,
you can see that they all look similar. Nerve cells working
together make nerve tissue, and skin cells make up a
special type of epithelial tissue.
4 Basic Tissue Types—this isn’t all of them
Connective tissue
connects and supports
parts of the body. Blood,
fat, ligaments, cartilage,
bones, and tendons are
all connective tissues.
Epithelial tissue covers and
lines the surfaces of your body
and organs, inside and out.
They primarily serve as
protective barriers. Skin is one
example.
Nervous tissue carries
messages back and forth
between the brain and every
other part of the body. The
brain, spinal cord, and
nerves are made up of
nerve tissue.
Muscle tissue can
contract, or shorten,
enabling your body to
move.
Level 4: Organs
When a bunch of different types of tissues
work together, they form an organ.
Organ Systems: 5th level
Each organ in your body is part
of an organ system, a group of
organs that work together to
perform a major function.
For example, your heart is part
of your circulatory system,
which carries oxygen and other
materials throughout your body.
Besides the heart, blood vessels
are organs that work in your
circulatory system.
Let’s Review….
•
1st Level: Organelles, specialized units that work together to form
cells
•
2nd Level: Cells, the building blocks of tissues
•
3rd Level: Tissues, groups of cells with specialized functions that
work together to form organs
•
4th Level: Organs, which are groups of tissues working together to
perform specific functions, such as the heart or brain
•
5th Level: Organ Systems, which are groups of organs working
together to complete a specific task
Ex: heart, blood, blood vessels all work together in
the circulatory system to move blood throughout the
body
•
6th Level: Organisms