Connective Tissues Presentation by Mahendra Kandel Email mkmahendrahotmail

Connective Tissues Presentation by: Mahendra Kandel Email: mk_mahendra@hotmail. com For: B Pharm, NIST Date: January 31, 2011 presentation by: Mahendra Kandel

What is connective tissue? Connective tissue- are deep tissues that are never exposed to the environment outside the body. Connective tissue is made up of by the combinations of different fibres, specialised cells and matrix. For egs. Cartilage, bone, blood, lymph, ligaments, fat. Connective tissue forms a framework upon which epithelial tissue rests and within which nerve tissue and muscle tissue are embedded. Blood vessels and nerves travel through presentation by: Mahendra Kandel connective tissue.

Whereas epithelial tissue consist almost entirely of cells, the extracellular matrix accounts for most of the volume of connective tissue. Matrix- is the ground substance of connective tissue. Several classes of connective tissue are recognized on the basis of the physical properties of the ground substance. presentation by: Mahendra Kandel

All connective tissues have three basic components: 1. Specialized cells 2. Protein fibers 3. A ground substance- is a fluid that varies in consistency. The extracellular fibers and ground substance constitute the matrix that surrounds the cell. presentation by: Mahendra Kandel

Specialisedpresentation cells, fibers and ground by: Mahendra Kandel substance of a connective tisue

Fibroblastsare the most abundant cells in connective tissue proper. They are responsible for the production and maintenance of the connective tissue fibers and ground substance The main function of fibroblasts is to maintain the structural integrity of connective tissues by continuously secreting precursors of the extracellular matrix. Fibroblasts secrete the precursors of all the components of the extracellular matrix, primarily the ground substance and a variety of fibres. The composition of the extracellular matrix determines the physical properties of connective tissues. presentation by: Mahendra Kandel

Macrophages. They tend to be somewhat larger than fibroblasts, with more cytoplasm. Macrophages contain numerous lysosomes which are used for breaking down ingested material. These lysosomes are usually inconspicuous by light microscopy but readily visible by electron microscopy. Macrophages are mobile (amoeboid movement) over short distances within a local region of connective tissue. These are scattered among the fibers, these cells engulf, or phagocytize, damaged cells or pathogens that enter the tissue and release chemicals the mobilize the immune system. Ex: White blood Cells (Monocytes) When an infection occurs, additional macrophages are drawn to by: the affected presentation Mahendra Kandel area.

Fat cells- Adipocytes are large connective tissue cells which contain a substantial amount of lipid stored in the form of conspicuous round droplets. Adipocytes function primarily as warehouses for reserve energy. They also assist in thermoregulation (maintaining body temperature) and in a few sites offer some cushioning capacity (e. g. , around kidneys, behind eyeballs). The number of fat cells varies from one connective tissue to another, from one region of the body to another and from individual to individual. presentation by: Mahendra Kandel

Mast cells“These are small, mobile connective tissue cells often found near blood vessels. The cytoplasm is packed with vesicles filled with chemicals that are released to begin the body’s defensive activities after an injury or infection. ” Mast cells occur as small individual cells, scattered rather widely in ordinary connective tissue. The cytoplasm of mast cells is packed with secretory vesicles, which can be fairly conspicuous in highquality light microscope preparations. The granules contain histamine, heparin, and various other chemical mediators whose release signals a number of physiological defense responses. Allergies are caused (in part) by inappropriate sensitivity of mast cells. The symptoms are treated with antihistamines, chemicals Mahendra Kandel which interfere with thepresentation action ofby: histamine.

There are three basic fiber types, what are they? 1. Collagen fibers- are long, straight, and unbranched. The most common fibers in connective tissue proper, they are strong but flexible. 2. Elastic fiber- contain the protein elastin, they are branched and wavy, and after stretching will return to their original length. 3. Reticular fiber- the least common of the three, are thinner than collagen fibers and commonly form a presentation by: Mahendra Kandel branching, interwoven framework in various organs.

Classification of Connective Tissue presentation by: Mahendra Kandel

Connective tissue proper includes the following five types: loose connective, dense connective, elastic, reticular, and adipose. They are called "proper" because they are the types usually meant when using the phrase "connective tissue” What is loose connective tissue? Loose connective tissue- (areola, little space)- is the least specialized connective tissue in the adult body. Contains all of the cells and fibers found in connective tissue, in presentation by: Mahendra Kandel addition to an extensive circulatory supply.

presentation by: Mahendra Kandel

What is adipose tissue? Adipose tissue or fat- is a loose connective tissue containing large numbers of fat cells. What is the difference between LCT and AT is : AT- provides another source of padding and shock absorption for the body. It also acts as an insulating blanket that slows heat loss through the skin and function in energy storage presentation by: Mahendra Kandel

presentation by: Mahendra Kandel

What is dense connective tissue? Dense connective tissues- consist mostly of collagen fibers, they may be also called white fibrous tissues. Where do we find these? Tendons- are cords of dense connective tissue that attachskeletal muscles to bones. Collagen fibers run along the length of the tendon and transfer the pull of the contracting muscle to the bone. What are ligaments? Ligaments- are bundles of fibers that connect one bone to another. Ligaments- often contain elastic fibers as well as collagen fibers and thus presentation by: Mahendra Kandel can tolerate a modest amount of stretching.

Functions of Connective Tissues 1. 2. 3. 4. 5. 6. 7. Support organs and soft tissues. Binding substance for organs and tissues. Protection of the body. Storage of fats and insulation. Hematopoeitic function. Protection against bacterial function. Repair of the body. presentation by: Mahendra Kandel

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