Histology

Front 1

Cells of Supporting Tissues are derived from?

Back 1

Precusor cells in Primitive supporting tissue AKA mesenchyme

Front 2

Fibroblast support cells are responsible for?

Back 2

secreting the extracellular matrix in most tissues

Front 3

Chondrocytes and Osteocytes are responsible for secreting the extracellular matrix where?

Back 3

Cartilage and Bone

Front 4

These have contractile function as well as a role in secretion of extracellular matrix?

Back 4

Myofibroblasts

Front 5

Main fibre type found in most supprting tisssues?

Back 5

Collagen

Front 6

In what form in Collagen secreted into the extracellular matrix?

Back 6

Tropocollagen

Front 7

Describe Collagen Type I

Back 7

Found in fibrous support tissue such as the dermis of the skin tendons ligaments and bone.
Tropocollogen molecules aggregated to form fibrils.

Front 8

Describe Collagen Type II

Back 8

Found in Hyaline Cartilage.
Consists of fine Fibrils which are dispersed in the ground substance

Front 9

Describe Collagen Type III

Back 9

Makes reticulin which has an affinity for silver salts.
Reticulin fibers found a reticular support meshwork in tissues such as liver, bone marrow and lymphoid organs

Front 10

Describe Collagen Type IV

Back 10

Does NOT form fibrils.
Forms a mesh- like structure.
It is a constituent of basement membranes

Front 11

Describe Collagen Type VII

Back 11

Forma achoring fibrils that link to basment membranes

Front 12

What type of connective tissue allows for stretching and elastic recoil?

Back 12

Elastin

Front 13

What synthesisizes elastin and what is the name of it's precurser?

Back 13

Secreted by Fibroblasts.
Precursor: Tropoelastin

Front 14

What is the importance of fibrillin?

Back 14

Required for the deposition of elastin in the form of fibres.

Front 15

The type of unbranched polysaccharide chain found in the ground subtance

Back 15

Glycosaminoglycans

Front 16

Are glycosaminoglycans basic or acidic?

Back 16

Acidic.
Due to the presence of hydroxyl, carboxyl and sulphate side groups.

Front 17

Name the seven GAGs found in the ground substance

Back 17

Hyaluronic acid.
Chrondroitin-4-sulphate.
Chondroitin-6-sulphate.
Dermatan sulphate.
Heparin Sulphate.
Keratan Sulphate.

Front 18

What is the predominant GAG found in loose supporting tissue?

Back 18

Hyaluronic acid.

Front 19

Desricbe Proteoglycans

Back 19

GAGs with the exception of Hyaluronic acid, covalently linked to a variety of protein molecules.
They may form non-covalent links with hyaluronic acid chainds to form larger molecules.

Front 20

What determines the permeability characteristics of a particular supporting tissue?

Back 20

The size of the spaces between the GAGs and the nature of the electrostatic changes.

Front 21

Describe Fibrillin

Back 21

Forms Mircofibrils 8-12 nm in diameter.
Appear to enchance adhesion between other extracellular consituents.
Fibrillin is a constituent of elastic fibres, appearing to play a role in orderly deposition of the fibres

Front 22

Describe Fibronectin

Back 22

Controls the deposition and orientation of collagen in the extracellular matrix and the binding of the cell to the extracellular material.

Front 23

Describe the role fibronectin plays in forming integrins or cell adhesion molescules

Back 23

A fibronectin receptor bonds within the cell to actin filament and with the fibronectin externally.
Fibronectin then binds with collagens and Heparin sulfate (a GAG)

Front 24

Where is Laminin mainly found?

Back 24

Basement membranes as a major component.

Front 25

What role does Laminin play?

Back 25

Forms links between cell membranes and other constitiuents of the basment membrane.

Front 26

What is the function of entactin?

Back 26

Binds laminin to Type IV Collagen in the basement membrane.

Front 27

Describe Tenascin?

Back 27

Binds to integrins and is important in the embryo, where is is involved in nerve cell growth

Front 28

What is the role of the basement membrane?

Back 28

Acts as an interface between the support tissues and parenchymal cells.
Also forms a limiting membrance around the CNS.
Provides metabolic support as well as binding the epitheium to the underlying supporting tissue.
Helps to Control epithelial growth and differentation.
Permints the flow of nutrients, metabolites and othe molecules to and form the epithelium.
Regulates permeability.

Front 29

Name the main constituents of basement membranes.

Back 29

Heparin Sulphate.
Collagen Type IV.
Structural Glycoprotein: Fibronesction, Laminin anad entactin.

Front 30

Describe the three layers of the basement membrane.

Back 30

Lamina Lucida: An electon-lucent layer that touchs the basal cell membrane of the parenchymal tissue.
Lamina Densa: The Intermeadiate layer that is electron dense.
Lamina fibroreticularis: A broad electron-lucent layer that merges with the underlying support tissue.

Front 31

What is the main function of fibroblasts

Back 31

To maintain the integrity of supporting tissures by continuous slow turnover of the extracellular matrix constituents.