Connective tissues 1. Structural peculiarities and classification 2. Loose connective tissue a. cells b. fibers 3. Dense connective tissue 4. Adipose tissue 5. Reticular tissue 6. Mucous tissue 7. Pigmental tissue

Structural peculiarities 1. Intercellular substance well developed 2. Different cells (principal, … and temporary) 3. Vessels Functions 1.Trophic 2.Protective (mechanical, immune) 3.Supportive 4.Plastic (adaptation, regeneration) 5.Morphogenetic (capsules, trabecules, regulation…)

Classification Proper connective tissues 1.Fibrous CT: 1. Loose 2. Dense ( regular, irregular ) 2.Special: 1. Adipose 2. Reticular 3. Mucous 4. Pigmental Skeletal connective tissues 1.Cartilages (hyaline, elastic, fibrous) 2.Bones: 1. Fibrous 2. Lamellar: compact and spongy)

Loose connective tissue

GROUPS OF CELLS A. Differon – obligatory cells 1. Stem cell 2. Hemistem cell 3. Fibroblasts immature and mature 4. Fibrocyte, myofibroblast, fibroclast B. Unobligatory cells - histiocytes, basophils, plasma cells, lymphocytes, adipocytes C. Temporary cells - neutrophils, eosinophils…

Section of an inflamed intestinal lamina propria

Fibroblast and fibrocyte

Fibroblasts in dense connective tissue

Macrophages=histiocytes Originate in red bone marrow Present everywhere Macrophagic system (Mechnikow) Protective functions 1.Engulfing and destruction 2.Decontamination in contact 3.Information transmit to immune cells 4.Stimulation of other protective mechanisms

Macrophages and eosiniphils

Mast cell ( basophil from blood) =labrocyte=Erlich cell

Mast cell

Plasma cells in connective tissue

Plasma cell ( B-lymphocyte)

Plasma cell

Fibers ( collagen, elastic and reticular )

Collagen fiber

Elastic fiber

Dense irregular connective tissue Loose connective tissue

Types of adipocytes

White and brown adipose tissue

Brown adipocyte Nerve ending nucleus liposome mitochondria GA

Reticular tissue ( reticular cells, reticular fibers ) in hematopoietic organs

Embryonal Connective Tissue—Gelatinous or Mucous Tissue 1e 2m5y 6al 4a 3v

. Wharton’s jelly from a mature human umbilical cord contains connective tissue cells (fibroblasts, fibrocytes) and a homogeneous gelatinous or gel-like ground substance, which holds the collagen fibers which run in all directions. The prevailing ground substances predominantly contains nonsulfatized glycosaminoglycans

Pigmental tissue melanocyte (melanin producing cell)

Melanogenesis 1.Tyrosinase is synthesized in the rough endoplasmic reticulum 2. Tyrosinase is accumulated in vesicles of the Golgi complex 3. The free vesicles are now called melanosomes. 4. Melanin synthesis begins in the stage II melanosomes, where melanin is accumulated 5. Stage III melanosomes. 6. III melanosome loses its tyrosinase activity and becomes a melanin granule. 7. Melanin granules migrate to the tips of the melanocyte’s processes and are then transferred to the keratinocytes of the malpighian layer.

Section of the stratum spinosum Melanin protects the DNA from the UV radiation of the sun.