1. CONNECTIVE TISSUE TYPES

2. CONNECTIVE TISSUE It is a type of tissue that connect and support other body tissues, also called supporting tissue. CLASSIFOCATION: Classified on the basis of following four criteria 1.Relative proportion of various fibers 2.Compactness and arrangements of these fibers 3.Nature of matrix 4.Types of cell present On the basis of factors mentioned above connective tissue is grouped into two main categories 1.Embryonal C.T 2.Adult C.T

3. EMBRYONAL C.T Developmentally the C.T are derived from mesoderm Immature C.T derived from mesoderm is called mesenchyma,it is composed f roughly star-shaped cells. As the development progress the mesenchyme gradually assumes the characteristics of adult C.T The first change is the appearance of fibers and the embryonal connective tissue of this stage is called mucous tissue. The umbilical cord contains considerable amount of mucous tissue which in this location is called warton’s jelly.

4. ADULT C.T It is further divided into following three main varieties 1.Connective tissue proper 2.Cartilage 3.bone

5. Types of Connective Tissue 2:CARTILAGE: I.Hyaline Cartilage II.Elastic Cartilage III.Fibrocartilage Cartilage 3: BONE A: EMBRYONAL C.T: I.Mesenchyme II.Mucous tissue B: ADULT C.T 1: connective tissue proper Loose Connective Tissue I.areolar II.reticular III.adipose DENSE CONNECTIVE TISSUE I.regular II.irregular

6. CONNECTIVE TISSUE PROPER Classified into further following two subtypes: 1.loose connective tissue 2.Dense connective tissue 1: LOOSE CONNECTIVE TISSUE: In Loose Connective Tissue, the fibers in the extracellular matrix are loosely arranged. Lots of ground substance. The ground substance is semifluid (viscous). Cells are scattered throughout the tissue. Not very cellular. LOOSE CONNECTIVE TISSUE INCLUDES: I.Areolar Connective Tissue II.Adipose Tissue III.Reticular Connective Tissue

7. LOOSE AREOLAR CONNECTIVE TISSUE Areolar is the most abundant type of connective tissue. All kind of fibers and cells are present. It is the packing and anchoring material of the body. It binds other tissues, organ components, and organs together and allow flexibility and mobility between such parts. form the supporting frame work (stroma) of most of the organs. examples: 1.Superficial and deep fascia 2.Mesentery 3.omentum

8. LOCATION: 1.Found in the subcutaneous layer deep to skin and in superficial part of dermis 2.mucus membranes 3.around blood vessels 4.nerves and body organs FUNCTION: supports glandular epithelium and mesothelial layers of mesentery, supports immune cells

10. RETICULAR CONNECTIVE TISSUE DESCRIPTION: R.C.T consists of reticular cells and reticular fibers. Reticular cells have stellate shape and possess long processes which pass in different directions to make contact with the neighboring cells. The dominant fiber is reticular fiber. Reticulocytes are fibroblasts that produce reticular fiber. The ground substance is semifluid. LOCATION: Found in lymph nodes and other non-muscular organs Provides a support structure for macrophages and other cells involved in immunity.

11. FUNCTION : forms the framework (stroma) of liver, spleen, bone marrow, and lymphoid organs. Produce reticular fibers Can also act as phagocytes May also give rise to precursors of erythrocytes and leukocytes

12. ADIPOSE TISSUE Consists almost entirely of fat cells arranged into lobules that are separated from each other by fibrous septa. Depending on its color, location and morphology of component cells, the adipose tissue is subdivided into two verities 1.WHITE OR UNILOCULAR ADIPOSE TISSUE Widely distributed in the body includes most of the adipose tissue of adult man. On naked eye it appears whitish or light yellow in color. Under L/M fat cells of white adipose tissue shows a single large fat droplet in the cytoplasm that is why they are called unilocular fat. The fat droplet is not membrane bound. These cells give a typical signet ring appearance in ordinary H%E stained sections

13. ADIPOSE TISSUE 2 : BROWN OR MUTILOCULAR ADIPOSE TISSUE On naked eye it appears brown The fat cells here have fat in the form of many small droplets instead of one droplet, that is why they are also called multilocular fat. In adult this tissue is absent or restricted in distribution but in fetus and child it is common The brownish appearance is due to two reasons 1.This tissue has a very rich capillary blood supply 2.These cells contain numerous mitochondria and are rich in cytochrome enzymes which have colored component

14. ADIPOSE TISSUE NOTE: as compared to other varieties of connective tissues the adipose tissue consist of cells and not intercellular substance. In other words the cell-intercellular substance ratio is ratio resemble that of the epithelium. Function: 1.Act as important food reserve of the body and chief site of energy storage (this function is restricted to white fat) 2.Mechanical function of acting as shock absorbing pads, in buttocks, soles etc. 3.Plays important role in temperature regulation which is accomplished by two following ways I.By heat production as a result of fat metabolism(function of brown adipose tissue) II.Acting as insulator to prevent heat loss from the body

16. Dense Connective Tissue The extracellular matrix consists of tightly packed parallel bundles of collagen fibers with less cells as compared to loose connective tissue and very little ground substance. It is less flexible and far more resistant to stress. According to its arrangement of component fibers it is divided into two categories 1.Regularly arranged dense C.T 2.Irregularly arranged dense C.T

17. REGULARLY ARRANGED DENSE C.T Fibers are densely packed and are parallel to each other Usually occur in the form of cords and bands Examples: tendons, aponeurosis and ligaments Tendons: Composed entirely of collagen fibers Fibers run parallel and closely packed in the form of bundles separated by a small quantity of intercellular substance. Fibroblasts are the only cells present The whole tendon is surrounded by a layer of fatty,coarse connective tissue sometimes called as epithelium

18. REGULARLY ARRANGED Dense C.T Apo-neurosis: Apo-neurosis have the same structure as tendon but these are broad and relatively thin. The fibers may be arranged in several superimposed layers, those of one layer running at an angle to fibers of the adjacent layer. Ligaments: Ligaments are bands of dense connective tissue. Structurally they resemble tendons because they are predominantly composed of collagenous fibers. A few ligaments consists entirely of elastic fibers, these are called yellow elastic ligaments.

20. IRREGULARLY ARRANGED DENSE C.T This variety of C.T occur in the form of sheets. Consist mainly of collagenous fibers but elastic and reticular fibers are also present. The components fibers interlace to form a network. Fibroblasts and some macrophages are found between the fibers. Location: Found in the dermis of the skin capsule of some organs (liver, testes, lymph nodes) Fibrous sheaths of cartilage (perichondrium) and bone (periosteum) Function: Provides strength and support to organs