Connective Tissue Unlike the closely packed, uniform cells of epithelial tissues, the varied cells of C.T. are widely spaced within an intercellular matrix which determines the characteristic and function of each specific C.T.

Connective Tissue Intercellular Matrix Components: Fibers Collagen – tough, white fibers of collagen protein Elastin – yellowish, elastic fibers Reticular – thin delicate fibers

Connective Tissue Intercellular Matrix Components: Ground Substance A semisolid gel containing water, glycoproteins, and other substances that are specific to particular C.T. types

Cells of Connective Tissue Connective Tissues have a variety of cell types: Mesenchymal cells- C.T. stem cells Fibroblasts- immature C.T. cells that form the matrix Fibrocytes- mature fibroblasts that no longer form matrix Macrophages- phagocytic cells (neutrophils) Mast Cells- secrete histamine and heparin for inflammatory response Plasma Cells- lymphocytes that secrete antibodies and can move into connective tissues from the circulation

Composition of Blood Formed Elements = 45% of Blood Volume Erythrocytes – red blood cells Leukocytes – white blood cells Thrombocytes - platelets Plasma – blood’s liquid portion Water – 91% Protein – albumin, fibrinogens, globulins Other solutes – nutrients, waste, gasses, electrolytes, hormones, steroids

Inflammatory Response Inflammatory Response | Khan Academy Click the Link Above to watch a lecture on the inflammatory response (15 minutes)