Connective tissue Introduction Types Fibers of connective tissue

Connective tissue Introduction Types Fibers of connective tissue Cells of connective tissue Ground substances

Connective tissue was given its name because it connects different type of tissue together. Types; 1. Ordinary connective tissue a. Loose connective tissue Dense regular b. Dense connective tissue Dense irregular 2. Mucoid c. t 3. Special c. t

Ordinary connective tissue Impotance for connecting various structure together in the body - Made up of fibers Cells ground substance

Components 1. 2. 3. 4. Cells Fibroblasts Macrophages Plasma cells Mast cells 5. Reticular cells 6. Adipocytes (fat cells) Matrix 1. Fibres-collagen -elastic -reticular 2. Ground Substance

1. Fibers of connective tissue 3 types -Collagen fibers -Elastic fibers -Reticular fibers

Collagen fibers: Fibrils run in various bundles. They are synthesized by fibroblast. If stained they look pink otherwise white that’s why its called white fibers.

Elastic fibers: unstained fibers look yellow in colour. Found single or bundles. When fibers cut ends will recoil. Synthesized by smooth muscles and fibroblast. They take weak pink stain

Reticular fibers: Very fine branched fibers. Commonly seen in liver and lymphoid organ. Bone marrow. Do not take haematoxyline and eosin They are synthesized by reticular cells or by fibroblast

Cells of connective tissue Fibroblast: These are stem cells with multiple process In resting phase cells appear spindle shaped called fibrocytes cell takes up basophilic stain. Found in all type of connective tissue t Produce ground substances.

Adipocytes (fat cells) Polygonal shape with eccentric nucleus Cytoplasm appear as thin rim around fat globule A group of fat cells called adipose tissue

Macrophages Irregular shaped cells with granules in cytoplasm Role in defense mechanism (phagocytic)

Plasma cells Round shape with eccentric nucleus Component of loose areolar tissue as well as lymphatic tissue. Cell is round with eccentriccally placed nucleus. cytoplasm is intensely basophilic due to abundant rough endoplasmic reticulum. Antibodies are synthesized and secreated by plasma cells. Plasma cells develop from b lymphocyte

Reticular cells Produce reticular fibres Phagocytic in nature

Mast cells Round shape with central nucleus Found in fibrous capsule of liver & spleen, around blood vessels Secrete heparin: anticoagulant Secret histamine: allergic reaction

White blood cells like lymphocytes and neutrophyils Lymphocytes are small large rounded cells with darkely stained nucleus. 2 types B and T lymphocytes. Neutrophils: - 3 to 5 lobed nucleus -fine eosinophilic granules -active during acute infection

Ground substances: Interfibrillar substance is called ground substance. Made up of acid gycosamino glycans. Proteoglycans, and water.

a. Loose (areolar) connective tissue Most common connective tissue Matric is semi solid Fibroblasts, mast cells & macrophages widely separated by elastic & collagen fibres Found Subcutaneous tissue Between muscles, blood vessels & nerves Space between organs

Dense connective tissue Fibers are closely packed with very little matrix and cells. 2 types irregular and regular Irregular found in region which experience considerable mechanical stress Regular –form sheet or bundles wherein direction of arranngement of fibers is related to the stress which they undergo

. Mucoid tissue: Embryonic connective tissue typically seen in the warton jelly forms the bulk in umbilical cord. Special connective tissues Bone and cartilage.

Adipose tissue • White adipose – 20 - 25% of body weight – Supportive function: around kidneys & eyes • Brown adipose – Newborns – Maintenance of body temperature