Fibrous tissue consists different groups of specialized cells that work together to perform specific functions within the body. These types of tissue — including connective, dense fibrous and reticular — are categorized according to the roles they play. The one constant in this type of tissue is that the fibers work together to create a continuous mesh around various muscle fibers.
One type of this tissue is known as fibrous connective tissue. This type of tissue is formed by elastic and collagen fibers and is used to bind other types of body tissues. Ligaments and tendons are made of fibrous connective tissue. There are no living cells in most of this connective tissue. Instead, it is made mostly of water, proteins, and polysaccharides.
Dense fibrous tissue is made mostly of collagen and tends to be white in color. This is the type of tissue that makes up the ligaments and tendons, as well as what is known as the aponeuroses, or layers of flat tendons. This type of tissue is also found on the layer of the skin called the dermis and on the capsules surrounding the organs of the body. It is sometimes divided even further into what is referred to as regular and irregular dense connective tissue.
Though it's also made of collagen, loose fibrous tissue, it is different from the dense tissue in that it also contains open spaces known as areolae. These spaces are filled with fluid and are found along with the collagen and elastic fibers making up the tissue. This type of tissue can be found in reticular, fibroelastic, and adipose tissues.
Reticular tissue is yet another type of fibrous tissue present in the body. The fibers making up this type of tissue are made from a different type of collagen than the type used by the body to form other kinds of fibrous tissue. These reticular fibers can be found in the lymphatic system as well as in some soft tissues of the body such as the liver and bone marrow.
Adipose tissue is sometimes considered among the types of fibrous tissue found within the human body. This is primarily due to the fact that adipose tissue is actually held together by the same reticular fibers that make up the reticular fibrous tissue in other parts of the body. It is also considered by some to be a type of loose fibrous tissue.