Connective Tissue A study in diversity Connective Tissue

Connective Tissue A study in diversity

Connective Tissue

4 major classes n Connective Tissue Fat n Fibrous n

4 major classes n Connective Tissue Fat n Fibrous n n Cartilage

4 major classes n Connective Tissue Fat n Fibrous n n n Cartilage Bone

4 major classes n Connective Tissue Fat n Fibrous n n Cartilage Bone Blood

4 major classes

4 major classes

4 major classes

4 major classes

Function of Connective Tissue Support

Function of Connective Tissue Support Protection

Function of Connective Tissue Support Protection Insulation

Function of Connective Tissue Support Protection Insulation Transport

Common Characteristics ? n They originate from the embryonic mesoderm

Common Characteristics ? n n They originate from the embryonic mesoderm Vasculature varies from avascular to vascular

Common Characteristics ? n n n They originate from the embryonic mesoderm Vasculature varies from avascular to vascular Makes a nonliving extracellular matrix

All connective tissue is made up of the following elements :

All connective tissue is made up of the following elements : Ground substance

All connective tissue is made up of the following elements : Ground substance Fibers

All connective tissue is made up of the following elements : Ground substance Fibers Cells

The ground substance and fibers make up the matrix

Ground Substance. n This is a featureless substance that is made up of water and proteins , much like raw egg whites in appearance and consistency.

The ground substance is made up of the following three components n Interstitial fluid

The ground substance is made up of the following three components n n Interstitial fluid Cell adhesion proteins

The ground substance is made up of the following three components n n n Interstitial fluid Cell adhesion proteins Proteoglycans

Interstitial Fluid n This is a solution that bathes and surrounds the cells of multicellular animals

Interstitial Fluid n n This is a solution that bathes and surrounds the cells of multicellular animals An average person has about 11 liters of interstitial fluid, providing the cells with nutrients and a means of waste removal.

Cell Adhesion Proteins (CAP) n Cell adhesion proteins (CAP) are involved in cell-cell and cell-extracellular matrix binding.

Cell Adhesion Proteins (CAP) n n Cell adhesion proteins (CAP) are involved in cell-cell and cell-extracellular matrix binding. The major classes of cell adhesion molecules are the integrins, cadherins, selectins and the immunoglobulins.

Cell Adhesion Proteins (CAP) n These are the glue that holds the cell and tissue together. They become continuous with the basement membrane and the various types of adhesion proteins such as desmosomes.

Proteoglycans n Are a complex group of proteins modified with sugar groups that control how viscous the ground substance is.

Proteoglycans n Proteoglycans are a major component of the matrix, the “filler” substance existing between cells in a tissue.

Proteoglycans n n Proteoglycans are a major component of the matrix, the “filler” substance existing between cells in a tissue. Examples of these include chondrotin sulfate and hyaluronic acid.

What are the function of these components of the matrix? n n n Interstitial fluid Cell adhesion proteins Proteoglycans

The Matrix

Fibers n There are three types of protein fibers which make up the matrix.

Fibers n n There are three types of protein fibers which make up the matrix. These protein fibers intermingle with the proteins of the ground substance.

Fibers n These proteins are: Collagen fibers n Elastic fibers n Reticular fibers n

Collagen n This is a heavily crossed linked protein and as a result is tough and has a high tensile strength. Grossly collagen appears white.

Collagen n It is the main component of connective tissue, and is the most abundant protein in mammals, making up about 25% to 35% of the whole-body protein content.

Collagen n n It is the main component of connective tissue, and is the most abundant protein in mammals, making up about 25% to 35% of the whole-body protein content. Collagen in tissues such as tendon, ligament and skin.

Elastic Fibers n Elastic tissue as the name implies can stretch like a rubber band

Elastic Fibers n n Elastic tissue as the name implies can stretch like a rubber band It is found in the skin and lungs

Elastic Fibers n n n Elastic tissue as the name implies can stretch like a rubber band It is found in the skin and lungs Elastin tends to deplete as people age, resulting in wrinkled or stretched out skin

Old Age

Reticular Fibers n Reticular fibers crosslink to form a fine meshwork (reticulum). .

Reticular Fibers n n Reticular fibers crosslink to form a fine meshwork (reticulum). This network acts as a supporting mesh in soft tissues such as liver and bone marrow and the tissues and organs of the lymphatic system.

Cell Component n In the tissue framework are “resident cells

Cell Component n n In the tissue framework are “resident cells These cells can become activated and form the characteristic fibers of their matrix.

Cell Component n Common cells include the:

Cell Component n n Common cells include the: Fibroblast- lays down the connective tissue matrix

Cell Component n n n Common cells include the: Fibroblast- lays down the connective tissue matrix Chondroblast- found in cartilage

Cell Component n n Common cells include the: Fibroblast- lays down the connective tissue matrix Chondroblast- found in cartilage Osteoblasts- found in bone

Cell Component n n n Common cells include the: Fibroblast- lays down the connective tissue matrix Chondroblast- found in cartilage Osteoblasts- found in bone Blood cells

Other Cells n Other cell types found in the connective tissue are often associated with the immune system and healing these include:

Other Cells n n n Other cell types found in the connective tissue are often associated with the immune system and healing these include: Fat cells White blood cells (neutrophils, eosinophils and lymphocytes) Macrophages Mast Cells

Connective Tissue Types Loose Connective Tissue (Areolar) n n n Widely distributed, surrounds the capillaries Cushions organs and is a reservoir for tissue fluid. Fibers are in know pattern.

Connective Tissue Types Loose Connective Tissue (Adipose) n n n Loose connective tissue packed with adipocytes Provides a reserve fuel, insulates and protects (cushions). Located under the skin, within the abdomen and breast.

Connective Tissue Types Loose Connective Tissue (Reticular) n n n The reticular network supports other cell types particularly those of the immune system. Found in the spleen, bone marrow and lymph glands. Reticular fibers are a type of collagen.

Connective Tissue Types Dense Connective Tissue (Dense Regular) n n n Fibers are parallel with very few cells. Major cell is the fibroblast. Makes up the ligaments and tendons and is very strong in one direction.

Connective Tissue Types Dense Connective Tissue (Dense Irregular) n n n Fibers are irregularly arranged with very few cells. Found in the dermis of the skin and fibrous capsules around joints. Function is to withstand forces from many directions.

Connective Tissue Types Cartilage (Hyaline) n n n A matrix with a fine collagen net work. . Chondroblasts produce the matrix. Has cushioning properties & is found in the trachea, ends o ribs and bones and tip of nose.

Connective Tissue Types Cartilage (Elastic) n n n A matrix with a fine elastic fibers forming a network. Supports external ear and epiglottis. Has great flexibility.

Connective Tissue Types Cartilage (Fibrous) n n n A matrix that is similar but less firm than hyaline. Can absorb compressive shock. Makes up the meniscus of the knee and intervertebral disks.

Connective Tissue Types Bone (Osseous Tissue) n n Has hard calcified matrix containing collagen. Supports body, provides a fulcrum for muscle action & site of blood cell formation.

Connective Tissue Types Blood n n Contains red and white blood cells in a fluid matrix, the plasma. . Transports nutrients and waste products.