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Connective TissueConnective Tissue1.1. Specialized CellsSpecialized Cells

2.2. Extracellular protein fibersExtracellular protein fibers

3.3. Ground substance=fluid Ground substance=fluid

Connective Tissues Connective Tissues Characteristics Characteristics

•Most diverse tissues of the bodyo CT never exposed to the outside

environment •Abundant extracellular matrix•Varying degrees of vascularity•Contain sensory receptors

Connective Tissue Connective Tissue FunctionsFunctions

• Support & Protection

• Transportation of Materials

• Storage of Energy Reserves

• Defense of the Body

Connective Tissue Connective Tissue Major Cell TypesMajor Cell Types

Fibroblasts• Fixed cell• Most common cell • Large, star-shaped cell• Produce fibers & GS

Macrophages• Wandering cell• Specialized for phagocytosis• Important in defense

Mast cells• Small, mobile •Found near blood vessels • Release chemicals to begin chemical defense

Fat cells•Adipose cells•Permanent

Connective Tissue Connective Tissue FibersFibers

Collagen fibers•Thick, long, straight •Unbranched•Composed of collagen•Great tensile strength •Abundant in dense CT•Hold structures together•Tendons, ligaments

Elastic fibers•Bundles of microfibrils •Embedded in elastin• Fibers branch• Elastic• Vocal cords, air passages

Reticular fibers• Very thin collagenous fibers• Highly branched• Form supportive networks•Least common

Reticularfibers

Fixedmacrophage

Antibodyproducing cell

Blood invessel

Adipocytes(fat cells)

Groundsubstance

Mast cell

Elasticfibers

Freemacrophage

Collagenfibers

Fibroblast

Stem cell

White bloodcell

Types of Connective Types of Connective TissuesTissuesCONNECTIVE TISSUES

CONNECTIVE TISSUE PROPER FLUID CONNECTIVE TISSUES SUPPORTING CONNECTIVE TISSUES

LOOSE DENSE BLOOD LYMPH CARTILAGE BONE

Solid, crystallinematrix

Solid, rubberymatrix

Flows withinlymphaticsystem

Flows withincardiovascular

system

Fibers denselypacked

Fibers createloose, openframework

Connective Tissue Connective Tissue ProperProperLooseLoose

Areolar Tissue• Mainly fibroblasts• Fluid to gel-like matrix• Collagen fibers• Elastic fibers•Highly vascular • Bind skin to structures• Beneath most epithelial• Between muscles

Adipose tissue• Adipocytes• Cushions• Insulates• Store fats• Beneath skin• Behind eyes• Around kidneys and heart

Connective Tissue Connective Tissue ProperProperLooseLoose

Reticular connective tissue• Composed of complex reticular fibers network• Supports framework• Walls of liver, spleen, lymphatic organs

Dense connective tissue• Packed collagenous fibers•Few fibroblasts•Poor blood supply

Connective Tissue ProperConnective Tissue ProperDenseDense

Dense Regular connective tissue• Parallel collagen fibers•Tightly packed fibers•Tendons-attach muscle to bone•Ligaments-attach bone to bone

Dense Irregular connective tissue•Interwoven meshwork with no pattern•Forms organ capsules, covers bone & cartilage & gives strength to skin

Fluid Connective TissueFluid Connective TissueBlood

•Fluid matrix called plasma• High # of red blood cells•Small # of white blood cells• Platelets-blood clotting• Transports• Defends• Clotting• Flows throughout body in blood vessels• Heart

Lymph• Flows within the lymphatic system•Contains white blood cells•Defends•Transports

Supporting Connective Supporting Connective Tissue-CartilageTissue-Cartilage

Cartilage• Rigid matrix• Chondrocytes in lacunae• Avascular • Three types

• Hyaline• Elastic• Fibrocartilage

Hyaline cartilage• Most abundant• Closely packed collagen fibers• Ends of bones• Nose, respiratory passages• Embryonic skeleton

Elastic cartilage• Flexible• Abundant elastic fibers• External ear, larynx

Fibrocartilage• Very tough• Many collagen fibers• Shock absorber• Intervertebral discs• Pads of knee and pelvic girdle

Hyaline Cartilage

Elastic Cartilage

Fibrocartilage

Three Types of CartilageThree Types of Cartilage

Supporting Supporting Connective Tissue-Connective Tissue-

BoneBoneBone

• Solid matrix• Supports• Protects• Forms blood cells• Attachment for muscles• Skeleton• Osteocytes-bone cells