Connective Tissue

Function• Bind together, Support & Strengthen organ systems• Protect and insulate internal organs• Compartmentalize structures (skeletal muscles)• Transport system (blood)• Stored energy (adipose)• Immune response (white blood cells)

Two Main Components• Extra cellular matrix– Consist of protein fiber

and ground substance• Cells– Cells not usually

touching each other– Lots of extracellular

matrix– Well vascularized

CELLS

MATRIXFIBER

GROUND SUBSTANCE

Cells

• Immature cells called “-blasts”• Mature cells called “-cytes”– Loose & dense CT• fibroblasts, fibrocytes

– Cartilage• chondroblasts, chondrocytes

– Bone • osteoblasts, osteocytes

Cell Types

• Fibroblasts– Most numerous, secrete fibers

• Macrophages– Type of WBC that phagocytizes

bacteria• Plasma Cells

– From B-lymphocytes, secrete antibodies

• Mast Cells– Secrete histamine, dilates blood

vessels• Adipocytes

– Fat cells, store triglycerides• White Blood Cells (WBC)

– Immune cells that migrate within CT

MAST CELL

ADIPOSE CELLS

PLASMA CELLS

The Matrix• Ground Substance

– Fluid, gel, calcified; between cells and fibers• Fibers

– Collagen• Strong, flexible, parallel fibers, resist stretch• Most abundant in body• Tendons and ligaments

– Elastic• Branching, fibrous network, of elastin and

fibrillin; VERY elastic• Skin, blood vessels, lung• Marfan’s Syndrome defective fibrillin gene

– Reticular• Collagen & glycoprotein network• Nerves, smooth muscle, spleen, lymph nodes

Classification of CT

• Embryonic• Mature– Loose– Dense– Cartilage– Bone– Blood & lymph

Loose CT

• Areolar

• Adipose

• Reticular

Dense CT

• Dense regular

• Dense irregular

• Elastic

Cartilage

• Hyaline

• Fibrocartilage

• Elastic cartilage

Bone

Blood & Lymph

Red Blood Cells

Lymphocyte (WBC)

Neutrophil (WBC)

Monocyte (WBC)

Platelets