The best way to distinguish connective tissues from other tissues is by the presence of an extracellular matrix. Matrix is a non-living material that is produced in the cells of connective tissues and then extruded out of the cells. Matrix is responsible for the strength of connective tissues, and there is much variation in matrix types due to the many functions of connective tissues. It contains a hard calcified matrix. Osseous tissue provides levers for muscles and allows for mineral storage.
Cartilage has a somewhat firm matrix.
It supports, reinforces, and cushions throughout the body. Blood contains a fluid matrix commonly called plasma. This tissue functions to transport substances throughout the body. Adipose cells are commonly known as fat cells. Adipose tissue has little matrix, and is characterized by the nucleus being pushed to the side of the cell by a large fat droplet.