Pathology Week 2

Repair occurs by lay down of

Connective tissue scar or glial scarring

Glial scarring occurs where

CNS

Repair occurs in tissues that were made up of

permanent cells

Repair occurs in tissues where

extensive destruction of the cellular matrix has occurred

Dense irregular connective tissue proper

scar tissue

Regeneration

Cellular division of adjacent cells that allows for regrowth of new tissue that is normal in structure and function

regeneration occurs in tissues made up of

labile cells

Collagen synthesis

fibroblasts

In RER formation of protocollagen with hydroxylation

requires vitamin C

where is collagen processed

Golgi

Once released into the extracellular environment procollagen is cleaved by

procollagen peptidase

procollagen peptidase

converts procollagen to tropocollagen

tropocollagen

basic unit of collagen

tropocollagen aggregates by

covalently bonding to other tropocollagen into collagen fibrils

fibrils form

collagen fibers

fibers form

bundles

tropocollagen functions

bonds to other tropocollagens to form collagen fibrils

most common collagen

Type 1

Type 1 collagen location

skin, bone, tendon, ligaments

mechanical characteristics of type 1 collagen

builds tensile force when stretched

Second type of collagen produced in skin wound healing

type 1

Type 2 collagen location

cartilage

type 2 collagen synthesized by

chondroblasts/cytes

Mechanical characteristics of type 2 cartilage

in articular cartilage withstands shear force at surface and compressive tensile forces at base

Type 3 collagen location

pliable tissues like blood, vessels, uterus, GI tract and skin

Type 3 collagen synthesized by

fibroblasts/cytes

mechanical characteristics of type 3 collagen

stretch and return (pliable)

first type of collagen to be synthesized with wound healing

Type 3 collagen

Type 4 collagen location

basement membrane

Type 4 collage is in all epithelial cells except for

de liver

Type 4 collagen CNS

Blodd vessels only

Type 4 collagen in the PNS

Schwan cells

Vascular endothelial cells have basement membranes except for

bone marrow, lymph nodes and vessels

All muscle cells have

type 4 collagen basement membrane

Adipocytes contain what collagen type

type 4 on basement membrane

Type 4 collagen is a component of

basment membrane

Type 4 collagen is synthesized by

cell that it originates from

Type 4 collagen characteristics

slectively permeable to charged materials, tensile strength to the structure underlying structure and cell attachment

Type 4 collagen is important for

regeneration

Elastic fibers location

pliable tissues like blood vessels, uterus, respiratory tracts and skin

elastic tissues synthesized by

fibroblasts/cytes

Elastic fibers characteristics

GAGs

Glycosaminoglycans; large protein molecules and water binding substances between the fibers of the Dermis

glycosaminoglycans and proteoglycans function

ossification

hydrophillic

orientation of collagen fibers

fibronectin comes from

plasma of damaged tissue

fibronectin connects

fibrin to collagen to GAGs

Fibronectins initiate

mechanical stability

fibronectin purpose is

to generate initial structural stability of a wound