Tissue type 2: connective tissue

what are the main functions of connective tissue?

binding, packing and support

Skeletal framework

Protection and defence

Insulation

Transportation/nourishment

Repair

what are the 2 types of connective tissue?

ordinary (proper)

Specialised

what are the 2 types of ordinary connective tissue?

loose

Dense

what are the characteristics of loose CT?

Less fibres

More cells

what are the characteristics of dense CT?

more fibres

Less cells

what are the types of loose CT?

loose

Adipose

Reticular

what are the types of dense CT?

irregular

Regular

Elastic

what are the types of specialised connective tissue?

supportive

Fluid

what are the supportive connective tissues?

cartiliage

Bone

what are the fluid connective tissues?

blood

Lymph

All connective tissues have:

fibres

Cells

Ground substance

what are the types of cells that may be found in CT?

Fixed

Wandering

what fibres are found in CT?

collagen

Reticular

Elastic

what is ground substance composed of?

highly hydrated gel

Glygosaminoglycans

Proteoglycans

Glycoproteins

fibres + ground substance =

extracellular matrix

is a fibroblast fixed or wandering?

Fixed

is a reticular cell fixed or wandering?

fixed

is an adipocyte fixed or wandering?

fixed

is a macrophage fixed or wandering?

wandering

is a plasma cell fixed or wandering?

wandering

is a mast cell fixed or wandering?

wandering

is a white blood cell fixed or wandering?

wandering

function of fibroblast

ECM production (structural)

function of reticular cell

production of reticular fibres

function of adipocyte

fat storage

function of macrophage

phagocytosis

function of plasma cell

antibody production

function of mast cell

chemical mediator (defence)

function of WBC

defence

what is the principal cell of ordinary connective tissue?

fibroblasts

What is produced by fibroblasts?

fibres and ground substance

fibroblast structure

abundant and irregularly branched cytoplasm with extensive RER and well developed golgi

Quiescent fibres (dormant) of fibroblasts

fibrocytes

type 1 collagen

provides tensile strength

type II collagen

hyaline and elastic cartilage

type III collagen

reticular

First collagen secreted in wound healing

which collagen is associated with wound healing?

type III

type IV collagen

basal lamina

type VII collagen

anchoring fibrils

assembly of collagen fibres

3 individual a-polypeptide chains combine within the cell to form procollagen

Pro collagen secreted from cell and proteolytic enzymes cleave pro peptides to form tropocollagen

Tropocollagen molecules align into linear arrays with a 67nm stagger to produce collagen fibrils

Collagen fibrils assemble to form a collagen fibre

Fibres → bundles

Elastic fibres location

dermis

Elastics arterioles

Lung

Certain cartiliages

elastic fibres structure

thin, branches fibres, required special stains to be seen

reticular fibres

collagen type III

reticular fibres stain with silver salts

black

which type of fibres do not form bundles?

reticular

Ground substance function

highly hydrated gel, interstitial fluid, functions as a molecular sieve through which nutrients diffuse between blood capillaries and cells

glycosaminoglycans

unbranched polysaccharide chains composed of repeating disaccharide units

Space filling, resistant to compression

Glycosaminoglycans function

regulate cell migration and movement through ECM

Binds and act as a reservoir for growth factors that signal to cells

4 main groups of glycosaminoglycans

hyaluronic acid

Keratin sulfate

Chrondroitin sulfate

Heparin sulfate

protoglycan structure

GAGs covalently attached to a core protein like a bottle brush

Individual proteoglycans are linked to hyaluron to form huge macromolecular complexes in tissues

see ordinary CT notes