Also known as mucopolysaccharide, it is the main component of matrix and is produced by fibroblasts

Sulfation

Non-Sulfated - Hyaluronic Acid

Among them, fibronectin plays an important role in cell recognition, adhesion, migration and proliferation.

It is an important medium for material exchange between blood and cells and becomes the internal environment for cells to survive.

It is the main fiber component in connective tissue. It is white and shiny when fresh. It is also called white fiber.

HE staining shows light red. The fibers vary in thickness and are wavy in diameter between 1 and 20 μm. They are branched and intertwined into a network. Their chemical composition is mainly collagen.

Under the electron microscope, collagen fibers are composed of collagen fibrils, showing periodic horizontal stripes of alternating light and dark, with a period of 64 nm.

Collagen fibers are tough, soft, easy to bend, and have strong tensile strength

The content is less than that of collagen fibers, but it is widely distributed. Diameter 0.2~1.0μm, yellow in fresh state, also known as yellow fiber

After HE staining and counterstaining with aldehyde-fuchsin, the elastic fibers appear purple-blue and the collagen fibers remain light red.

Made of microfibrils, highly elastic

Diameter 0.2~1.0μm, with 64nm periodic striations

HE staining is not easy to stain, PAS reaction is positive, and it is argyrophilic. It can be dyed black with silver staining.

Mainly distributed in reticular tissue (around hematopoietic organs, follicles, capillaries), and also at the junction of connective tissue and other tissues (such as the reticular plate of the basement membrane)

It is the most important cell in loose connective tissue.

Under a light microscope, the cells are large, with flat and irregular cell bodies and multiple protrusions; the nuclei are large, oval, and have obvious nucleoli; the cytoplasm is rich and weakly basophilic.

It can synthesize and secrete collagen and elastin, which constitute the three types of fibers in loose connective tissue. It can also synthesize and secrete matrix.

Transform into fibroblasts when their functions are at rest. Fibroblasts can also transform into fibroblasts under certain conditions.

Under a light microscope, cell morphology changes due to different functional states. It is generally round or oval in shape, with short protrusions. When the function is active, long pseudopods are often extended and the shape is irregular; the nucleus is small, oval, darkly colored, and the nucleolus is not obvious; the cytoplasm is rich and numerous. Eosinophilic

It has specific and non-specific phagocytic functions; it is an antigen-presenting cell that can synthesize and secrete hundreds of active substances.

Under a light microscope, the cell body is round or oval; the nucleus is round and is a biased nucleus, with thick heterochromatin, mostly distributed in the nuclear membrane, arranged in a wheel shape; the cytoplasm is rich, basophilic, and the nucleus There is a lightly dyed area next to it

Can synthesize and secrete immunoglobulins (antibodies) and participate in humoral immunity

Under a light microscope, the cell body is large, round or oval; the nucleus is small and round, deeply stained, and located in the center; the cytoplasm is rich and filled with a large number of thick metachromatic basophilic granules that are easily soluble in water.

Mast cells are often distributed along small blood vessels, especially in the dermis of the skin, the connective tissue of the digestive tract and respiratory mucosa

Closely related to allergic reactions

A small number of stem cells that still retain differentiation potential in connective tissue

Often distributed in small blood vessels, especially around capillaries