Question

3) Connective tissue types can be categorized by the extracellular matrix that the cells excrete. What types of extracellular substances will you observe during lab?

Answer 1

Connective tissue consists of individual cells scatteredwithin an extracellular matrix.Connective tissue are not directly attached to one another. Individual connective tissue cells are normally separated from one another by varying amounts of extracellulsar matrix.

The most common connective tissue cells are fibroblasts which secrete collagen and other elements of the extracellular matrix ,adipocytes which store fat , lymphocytes which participate in inflammation.

Connective tissue matrix is composed of ground substance and fibres.In bone,the ground substance includes minerals and in blood the ground substance includes plasma.

The matrix is produced by fibroblast (or related cell types -cnondroblast in cartilage and osteoblast in bone)

Connective tissue consists of cels separated by varying amounts of extracellular substance.The extracellularsubstance consists of fibres which are embedded in the ground substance containing tissue fluid.the extracellular substance are 1. Collagen fibres - It is the dominant fibre type in most connective tissue.The primary function of it is to add strength to the connective tissue.Thickness of fibres varies from 1 to 10 micro meter.Longitudinal striations may be visible in thicker fibres.These styriations reveal that the fibres are composed of thinner collagen fibrils .2 to .5 micrometer in diameter. Each of these fibrils is composed of microfibrils, which are only visible using electron microscopy.

2. Reticular fibres are very delicate and form fine networks instead of thick bundles.They are usually not visible in histological sections but can be demonstrated by using special stains for exa,ple, in silver stained sections reticular fibres look like fine,black threads-coarse collagen fibres appear reddish brown in the same type of preparation.

3.Elastic fibres are coloured in fresh tissue -they are light yellow - but this colouration is only visible if large amounts of fibres are present in the tissue.Light microscopy doesnot reveal any substructure in the elastic fibres.Electron microscopy shows the elastic fibres consist of individual microscopy shows that elastic fibres consist of individual micrifibrils, which are embedded in an amorphous matrix.