Loose vs Dense Connective Tissue
Four types of basic tissues can be found in the human body; namely, epithelial tissue, connective tissue, muscle tissue, and nervous tissue. Considering the structure and wide variety of functions, connective tissue is the most known diverse tissue out of all basic tissues. The structure of connective tissue varies from soft gel like loose (areolar) connective tissue to hard bones. Consisting of extra cellular matrix with ground substances and fibers is the unique characteristic feature of this special tissue. Based on the types and relative abundance of cells, organization of fibers and ground substances, connective tissue can be classified into several categories. Loose and dense connective tissues are two important types from them.
Loose Connective Tissue
Loose connective tissue owns its name due to the loose arrangement of fibers and cells in the matrix. Its viscous gel-like nature is important for the oxygen and nutrient diffusion from small vessels and diffusion of metabolites back to the vessels. The loose connective tissue can be found beneath epithelial tissue that lines the internal body surfaces, glands, and around small vessels. The major cell type found in the loose connective tissue is fibroblasts, which produce and maintain the fibers and ground substance of the matrix. They are spindle shaped cells and are scattered mostly throughout the matrix. Even though fibers are not abundant in loose connective tissue, collagen fibers are the main fiber type found in loose connective tissue.
Dense Connective Tissue
The fibers are abundant and densely arranged in dense connective tissue, though it has the same cells, ground substance, and fibers as loose connective tissue. Dense connective tissue can be found where strength is needed. Depending on the arrangement of fibers, dense connective tissue can be classified into two distinct forms; namely, dense irregular connective tissue and dense regular connective tissue.
In dense irregular connective tissue, the fibers have no specific direction of arrangement. Therefore, it is used where the tension will apply in multiple directions. In dense regular tissue, the fibers are arraigned parallel to each other in one direction. Hence, this can be found where the strength is needed, but the force is applied in one direction. This can be classified also as dense collagenous connective tissue, when the tensile strength of “collagen” is needed, and dense elastic connective tissue, when the elasticity of “elastin” is needed.
What is the difference between Loose and Dense Connective Tissue?
• Large proportion of ground substance and cells can be found in loose connective tissue, whereas these substances are found in small quantities in dense connective tissue.
• Few loosely arraigned fibers can be found in loose connective tissue, whereas fibers are arranged densely and abundantly in dense connective tissue.
• Loose connective tissue has more vessels than that of dense connective tissue.
• The loose connective tissue can be found beneath the epithelial tissue that lines the internal body surfaces, glands, and around small vessels.
• Dense connective tissue is found on the outside of many organs, in the dermis of the skin and submucosa, within various organs as dense irregular connective, and in tendons, ligaments, and aponeuroses as dense regular connective tissue.