anatomy 1

Four main classes of connective tissue

connective tissue proper, cartilage, bone, blood

Connective Tissue Proper Subclasses

Loose connective tissues Areolar, Adipose, Reticular

Connective Tissue Proper Cells

Fibroblast, Fibrocytes, Defense Cells, Adipocytes

Connective Tissue Proper Matrix

gel-like ground substance, all three fiber types: collagen, reticular, elastic

Connective Tissue Proper General Features

-six different types; vary in density and types of fibers

-functions as a binding tissue

-resists mechanical stress, particularly tension

-provides reservoir for water and salts

-nutrient (fat) storage

Dense Regular Connective Tissue Subclasses

Dense Connective Tissue

Regular

Irregular

Elastic

Cartilage Subclasses

hyaline, elastic, fibrocartilage

Cartilage Cells

chondroblasts found in growing cartilage

Chondrocytes

Cartilage Matrix

-gel-like ground substance

-fibers: collagen, elastic fibers in some

Cartilage General Features

resists compression because of the large amounts of water held in the matrix, functions to cushion and support body structures

Bone tissue subclasses

compact bone and spongy bone

Bone tissue cells

osteoblasts and osteocytes

bone tissue matrix

Gel-like ground substance calcified with inorganic salts

Fibers: collagen

Bone tissue General Features

hard tissue that resists both compression and tension, functions in support

Blood cells

erythrocytes, leukocytes, platelets

blood matrix

plasma, no fibers

Blood General features

-a fluid tissue

• functions to carry O2, CO2, nutrients, wastes, and other substances (such as hormones)

Major Functions of Connective Tissue

Binding and support

Protecting

Insulating

Storing reserve fuel

Transporting substances (blood)

Characteristics of Connective Tissue 1

Have mesenchyme (an embryonic tissue) as their common tissue of origin 1

Characteristics of Connective Tissue 2

Have varying degrees of vascularity (blood vessels) 2

Characteristics of Connective Tissue 3

Have extracellular matrix

Structural Elements of Connective Tissue

Ground substance

Fibers

Cells

Ground Substance

Unstructured material that fills space between cells /

Collagen

Strongest and most abundant type

Tough; provides high tensile strength

Elastic fibers

Networks of long, thin, elastin fibers that allow for stretch and recoil

Reticular

Short, fine, highly branched collagenous fibers (different chemistry and form than collagen fibers)

Branch, forming networks that offer more "give"

"Blast" cells

immature form; mitotically active; secrete ground substance and fibers

Fibroblasts

in connective tissue proper

Chondroblasts

in cartilage

Osteoblasts

in bone

"Cyte" cells

Mature form; maintain matrix

Chondrocytes

in cartilage

Osteocytes

in bone

Fat cells

Store nutrients

White blood cells

Neutrophils, eosinophils, lymphocytes

Tissue response to injury

Mast cells

Initiate local inflammatory response against foreign microorganisms they detect

Macrophages

Phagocytic cells that "eat" dead cells, microorganisms; function in immune system

All connective tissues except bone, cartilage and blood

T

Loose connective tissues

Areolar

Adipose

Reticular

Dense connective tissues (also called fibrous connective tissues)

Dense regular

Dense irregular

Elastic

Support and bind other tissues

Universal packing material between other tissues

Most widely distributed

Provide reservoir of water and salts

Defend against infection

Store nutrients as fat

Fibroblasts

Loose arrangement of fibers

Ground substance

When inflamed soaks up fluid 🡪 edema

Areolar Connective Tissue

White fat

Similar to areolar but greater nutrient storage

Cell is adipocyte

Stores nutrients

Scanty matrix

Richly vascularized

Shock absorption, insulation, energy storage

Brown fat

Use lipid fuels to heat bloodstream not to produce ATP

Adipose Tissue

Reticular Connective Tissue

Resembles areolar but fibers are reticular fibers

Fibroblasts called reticular cells

Supports free blood cells in lymph nodes, the spleen, and bone marrow

areolar

adipose

Resembles areolar but fibers are reticular fibers

Fibroblasts called reticular cells

Supports free blood cells in lymph nodes, the spleen, and bone marrow

Reticular Connective Tissue

reticular

Closely packed bundles of collagen fibers running parallel to direction of pull

White structures with great resistance to pulling

Fibers slightly wavy so stretch a little

Fibroblasts manufacture fibers and ground substance

Few cells

Poorly vascularized

Dense Regular Connective Tissue

dense regular

Same elements but bundles of collagen thicker and irregularly arranged