Connective tissues bind structures together, provide support and protection, serve as frameworks, fill spaces, store fat, produce blood cells, protect against infections, and help repair tissue damage. Connective tissue cells are usually spaced farther apart than epithelial cells, and they have an abundance of intercellular material, or matrix, between them. This matrix consists of fibers and a ground substance whose consistency varies from fluid (blood) to semisolid (cartilage) to solid (bone).
Connective tissue cells are usually able to divide and replace themselves. In most cases, they have good blood supplies and are well nourished. Some connective tissues, such as bone and cartilage, are quite rigid. Loose fibrous connective tissue, adipose tissue, and dense fibrous connective tissue are more flexible.