Classification of connective tissue

Connective tissue is a complex of derivatives of mesenchymal origin, consisting of cellular differons and intercellular substance involved in maintaining homeostasis of the internal environment of the body.

 

Connective tissue (CT) makes up more than 50% of a human body weight.

forms the stroma of parenchymal organs, part of the walls of hollow organs

CT formed skin dermis and skeleton

FUNCTIONS:

- trophic

- protective

- supporting

- plastic (adaptation, regeneration)

- morphogenetic (structure-forming)

MORPHOLOGICAL FITURES

1. All types of CT develop from mesenchyme

2. All types of CT are composed of cells and intercellular substance, which:

consists of fibers and ground substance (quantitatively prevails over cells)

3. The functions which performed by CT are determined by the physicochemical state of the intercellular substance.

4. High ability to regenerate

CLASSIFICATION OF CONNECTIVE TISSUE

The loose fibrous CT is characterized by the predominance of cells and the main amorphous substance over the fibers.

A dense CT contains more fibers than cells and the main amorphous substance:

- in a dense, formed CT, the fibers lie parallel to each other (tendon)

- in a dense unformed CT fiber are randomly located (dermis of the skin)

CELLS OF CONNECTIVE TISSUE

Fibroblast Differon, macrophages, mast cells, plasma cells, pericytes, adipocytes, adventitional cells, pigment cells, white blood cells

 

Differon - a collection of cells that make up one line of differentiation - from the least to the most

Differentiated

Loose irregular connective tissue (picture)

Collagen fiber, 3-fibroblast, 7-macrophages

 

DIFFERON OF FIBROBLAST:

Stem cell

↓

Hemi stem cell

↓

undifferentiated fibroblast

↓

Differentiated fibroblast

↓

Fibrocyte

Myofibroblast, Fibroclast

Undifferentiated fibroblasts

SIZE 20-25 microns, Endoplasmic reticulum is poorly developed, low protein synthesis.

Differentiated fibroblasts -Size: 40-50 microns, biosynthesis is intensive. The cytoplasm contains microfilaments, which determines the ability of cells to move. PRODUCE ALL COMPONENTS OF EXTRACELLULAR MATRIX (collagen, elastin)

Fibrocytes - have a fusiform shape an. It is old definitive form of fibroblast. Has low functional activity

Myofibroblasts are functionally similar to both: fibroblast and smooth muscle cells. PRODUCE COLLAGEN, Elastin and contractile proteins (actin, myosin).Observed in granulation tissue and uterus during pregnancy

Fibroclasts - take part in the resorption of intercellular substance during the period of involution.

 

Macrophage

Macrophage Precursors - Blood Monocytes

Macrophages can be:

- free

- fixed

Free i nclude macrophages of LICT (histiocytes), serous cavities, inflammatory exudates, lungs.

Fixed (resident) include macrophages of CMC, l / y, spleen, osteoclasts, microglia.

The nuclei are round, in the cytoplasm there are many lysosomes and phagosomes.

Cell peripherals rich in cytoskeletal elements, due to which the movement of cells, endo- and exocytosis are ensured.

On the surface of the plasma membrane are receptors for tumor cells, E, T and B lymphocytes, hormones, antigens.

FUNCTIONS : Phagocytosis - absorption of foreign material and its neutralization

               Transmission of antigen information to immunocompetent cells (antigen presentation)

               They produce IL-1, growth factors, antitumor factors.

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The amount of M increases with inflammatory processes.

MUST CELLS

The shape of the cells is oval or round, with short processes.

The cytoplasm contains granules:

- basophilic metachromatic (with heparin, histamine, hyaluronic acid, serotonin).

- azurophilic (lysosomes).

Mast cells are capable of degranulation in response to any changes. Histamine immediately causes the expansion of blood capillaries, increases their permeability, which manifests itself in local edema. Heparin reduces blood coagulation.

 

PLASMA CELL

Formed in lymphoid organs from b-lymphocytes

They are localized in the CT of the tunica mucousa, in the lymphoid organs, in the connective tissue of the glands.

They are stained basophilically, contain a large amount of rER in the cytoplasm.

The light area near the core forms a sphere or courtyard.

Antibodies (immunoglobulins) are formed on rER membranes

ADIPOCYTES

GROUND SUBSTANCE

COLLAGEN FIBERS

ELASTIC FIBERS

TENDON

RETICULAR CONNECTIVE TISSUE

consists of reticular cells and reticular (argyrophilic - stained with silver salts) fibers that form a three-dimensional network.

RT forms the stroma of the blood-forming organs and forms a microenvironment for developing formed blood elements

ADIPOSE TISSUE (AT)

It is divided into white and brown VT.

Brown AT is found in newborns (under the skin between the shoulder blades, behind the sternum, on the neck, along the spine, around the kidneys), rodents and animals hibernating.

White AT is located under the skin everywhere.

Adipose tissue consists of clusters of cells (adipocytes), entwined with capillaries. Clusters of cells are clearly divided by layers of CT into segments of different sizes. In the spaces between the fat cells are fibroblasts, tk. basophils, capillaries, collagen fibers.

Brown AT cells have many inclusions in the cytoplasm, a large number of mitochondria.

Brown color is associated with the presence of an iron-containing pigment - cytochrome mitochondria.

The oxidizing ability of brown ad.cells is 20 times higher than in white. With decreasing temperature, the activity of oxidative processes in brown ad.cells increases, energy is released that heats the blood in the capillaries

During starvation, fat cells lose their fat stores and become stellate or fusiform

MUCOSE CONNECTIVE TISSUE

Contained in the umbilical cord (Wharton jelly)

CONTEINS cells - fibroblasts, myofibroblasts, smooth myocytes.

And type IV collagen, high concentration of hyaluronic acid (binds water)

 

Connective tissue is a complex of derivatives of mesenchymal origin, consisting of cellular differons and intercellular substance involved in maintaining homeostasis of the internal environment of the body.

 

Connective tissue (CT) makes up more than 50% of a human body weight.

forms the stroma of parenchymal organs, part of the walls of hollow organs

CT formed skin dermis and skeleton

FUNCTIONS:

- trophic

- protective

- supporting

- plastic (adaptation, regeneration)

- morphogenetic (structure-forming)

MORPHOLOGICAL FITURES

1. All types of CT develop from mesenchyme

2. All types of CT are composed of cells and intercellular substance, which:

consists of fibers and ground substance (quantitatively prevails over cells)

3. The functions which performed by CT are determined by the physicochemical state of the intercellular substance.

4. High ability to regenerate

CLASSIFICATION OF CONNECTIVE TISSUE

The loose fibrous CT is characterized by the predominance of cells and the main amorphous substance over the fibers.

A dense CT contains more fibers than cells and the main amorphous substance:

- in a dense, formed CT, the fibers lie parallel to each other (tendon)

- in a dense unformed CT fiber are randomly located (dermis of the skin)

CELLS OF CONNECTIVE TISSUE

Fibroblast Differon, macrophages, mast cells, plasma cells, pericytes, adipocytes, adventitional cells, pigment cells, white blood cells