Bone is a hard, somewhat flexible type of
connective tissue that makes up the animal skeleton
(see picture below). Any part of the skeleton is
known as bone and the average person has a total
of 206 bones. The inside of bone consists of loose,
spongy tissue that is passed through by many types
of blood vessels and nerves, as well as by vessels
that transport a fluid called lymph.
The spongy tissue inside bones is surrounded by
closely packed bony tissue. This closely packed
bony tissue is surrounded by a thin layer of tissue
known as the periosteum. The connective tissue that
makes up bones is closely enclosed in an area of
collagen (a type of fiber) and a mineralized
Above: The human skeleton.
WHAT IS INSIDE THE FIBERS THAT MAKE
For one, an odorless, tasteless chemical
powder known as calcium phosphate is inside
these fibers. There are also large amounts of
the mineral, magnesium, as well as two types of
salt: 1) carbonate, and 2) citrate sodium.
Organic material makes up 25% of bone,
whereas inorganic material makes up the other
HOW IS BONE TISSUE CREATED?
The tissue that makes up bone are created by cells known as osteocytes. Osteocytes
create bone tissue in a complex system of interconnecting canals and concentric rings,
which means that the rings overlap and share a common center. The circular layers of
bone are formed around a blood vessel canal in the center.
Organic material is that which is made of the element, carbon, and held together by bonds that are made
by shared electrons (negatively charged atomic particles). Inorganic material is made of atoms other
than carbon and is held together by forces other than bonds made by shared electrons.
WHAT ABOUT BONE MARROW?
The center of long bones are filled with a type of tissue known as marrow. If you want to get a sense of
what bone marrow looks like, the next time you are eating chicken wings, break one of the bones in half
and take a look at the pink stuff inside (bone marrow). The marrow inside the long openings of long
bones is yellow. By contrast, red marrow (which makes blood cells) is present near in the ends of bones
by the joints. Red marrow also fills the openings of bones that are short as well as bones that are flat.
Other bones that red marrow fills are the ribs, the central part of the bones that make up the spinal
column, and a long and flat bone that goes down the center of the chest (known as the sternum).
WHAT IS THE ORIGIN OF THE WORD, BONE?
Bone comes from the Anglo-Saxon word "ban" meaning "bone."