Let’s review… 1.What are the 2 types of Epithelial tissues? 2.What are the 2 types of Glands? 3.Describe the 4 shapes of cells— 4.What is the difference between “simple” and “stratified”? 5.What’s a “germ layer” ? 6.Define “distended”. 7.What are “goblet cells”? 8.What is “pseudostratified” columnar epithelium?

… are the most abundant of all the 4 tissue types

The cells of connective tissue are far apart, separated by an abundant amount of extracellular material called … cell capillary Basement membrane matrix fiber cell

Where do you find connective tisssue? Everywhere in the body !!

Functions of connective tissue 1. Binding, supporting, packaging – holds other tissues in place 2. Protection, defense, & repair – scar tissue, inflammation 3. Insulation – fat cells or Adipose tissue 4. Transportation - blood

Classification of Connective Tissues Connective tissues are identified on the basis of three criteria: 1. Cell types 2. Kind, density, and arrangement of fibers 3. Amount & nature of the amorphous ground substance

Ground substance + fibers = Extracellular matrix

The CELLS found in connective tissues can be placed in 2 categories: a. those that secrete the matrix or maintain it – cell type ends in –blast, –cyte, or -clast; b. accessory cells which are supported by the connective tissue – fat-storing cells, white blood cells, and other cells that are involved in body defense and the elimination of dying/dead tissue cells;

The GROUND SUBSTANCE is the amorphous substance that fills the space between the cells and contains the fibers. It is composed of interstitial fluid (liquid between cells), proteins, and polysaccharides – the more polysaccharides the stiffer the ground substance.

FIBERS in the matrix provide strength. Three types of fibers are found in the connective tissue matrix: 1. Collagen fibers – white, very tough, high tensile strength 2. Elastic fibers – yellow, found where elasticity is needed like lungs and blood vessels 3. Reticular fibers – fine collagenous fibers, delicate branching network supporting soft organs like liver & spleen

Classification of connective tissues

BLOOD Involved in defense – fight infection and make antibodies; transportation of materials; Erythrocyte – red cell Leukocyte – white cell Thrombocyte – platelet Plasma – watery matrix

BONE Osteocytes Osteoblasts Osteoclasts bone-building bone-destroying

CARTILAGE Chondrocytes HYALINE cartilage in growth plates, ends of long bones, rings of trachea, and fetal skeleton ELASTIC cartilage in outer ear FIBROCARTILAGE pads between vertebrae and knee cartilage

CONNECTIVE TISSUE PROPER AREOLAR – mucous membranes, around blood vessels, nerves, and organs ADIPOSE – fat around organs, under the skin, in yellow bone marrow RETICULAR – liver, spleen, lymph nodes DENSE REGULAR – tendons (connect muscle to bone) and ligaments (connect bone to bone) DENSE IRREGULAR – dermis