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Connective tissue


The connective tissue cells are spaced apart, and the space between them is filled with intercellular substance. The main function of connective tissue is to unite and support the organs of the body.

This type of tissue has several cell groups that have their own characteristics. For this reason, it is subdivided into other tissue types. They are: adipose tissue, cartilaginous tissue, bone tissue, blood tissue.

Adipose tissue

It is formed by adipocytes, that is, cells that store fat. This tissue lies below the skin, forming the adipose panicle, and is also arranged around some organs. The functions of this tissue are: to provide energy to the body; act as a thermal insulator, reducing the heat loss from the body to the environment; offer protection against mechanical shocks (strokes, for example).


Optical microscope image of adipose tissue. Note that the lines are the cell boundaries and the purple dots are the adipocyte nuclei. The light part, looking like an empty space, is the part of the cell made up of fat.

It forms the cartilage of the nose, ear, trachea and is present in the joints of most bones. It is a tough but flexible fabric.


Nose and ear are formed by cartilage.


Cartilage cells seen under the optical microscope.

It forms the bones. Its rigidity (hardness) is due to the impregnation of calcium salts in the intercellular substance.

The human skeleton is an articulated structure made up of 206 bones. Although the bones are rigid, the skeleton is flexible, allowing broad body movements thanks to muscle action.

It constitutes the blood, liquid tissue. It is formed by different cell types such as:

  • the red blood cells or Red Cells, which carry oxygen;
  • the White blood cells or leukocytes, which act in the defense of the body against invading microorganisms;
  • fragments (pieces) of cells, as is the case with platelets, which act on blood clotting.

The intercellular substance of blood tissue is plasma, consisting primarily of water, responsible for transporting nutrients and other substances to all cells.

Components of blood seen in an electron microscope. The red cells are the red blood cells and the white is the white blood cell.