[Connective tissue diseases in adolescents]

Connective tissues are one of the four main tissue types in humans that are extensively present in the body. They are characterized by cells embedded in an extracellular matrix (ECM) composed of a ground substance and three main types of protein fibers— collagen, elastic, and reticular fibers. The ground substance of connective tissues can range from a watery and jelly-like consistency to mineralized and hard. The wide variety of cells in the connective tissues include fibroblasts,...

Connective tissue develops from the mesoderm of a developing embryo and consists of cells, fibers, and ground substance: a gel-like material containing large complexes of carbohydrates and proteins. Connective tissue was first identified as a separate tissue family in the 18th century, and Johannes Peter Muller coined the term connective tissue.
Fat cells (adipocytes), smooth muscle cells (myoblasts), and bone cells (osteoblasts) are some connective tissue cell types. Some immune system cells...

The connective tissues have different properties and functions in the human body. They are broadly categorized into proper, supporting, or fluid connective tissues.
Connective Tissue Proper
Connective tissue proper is the most abundant class of connective tissues. As its name implies, it predominantly connects different tissues in the body. Depending on the cell types, ground substance, viscosity, and fiber types in the ECM, connective tissue proper is further categorized into loose and dense....

Loose connective tissue is found between many organs. Its main function is to absorb shock and bind tissues together. It also allows water, salts, and various nutrients to diffuse into cells that are embedded in it or present in adjacent tissues.
Adipose Tissue
Adipose tissue consists primarily of fat storage cells called adipocytes and little extracellular matrix. A large number of capillaries present within adipose tissue allow rapid mobilization of lipid molecules. White adipose tissue is...

Unlike epithelial tissue, which is composed of cells closely packed with little or no extracellular space in between, connective tissue cells are dispersed in a matrix. This extracellular matrix (ECM) is composed of fibrous proteins like collagen, elastin, and fibronectin in a ground substance consisting of interstitial fluid, cell adhesion proteins, and proteoglycans. The proteoglycans form a gel-like material in the spaces between cells and provide hydration, buffering, binding, and force...

Connective tissues perform a broad range of functions in the body. Their primary function is to connect and link different tissues in the body and act as packaging material between tissues. The areolar tissue, a connective tissue prototype, commonly cements various tissue types in diverse body organs. In contrast, adipose tissue cushions internal organs while insulating the body from heat loss.
Hard connective tissues, such as bones and cartilage, provide structure and support to the body.