Fibrillært Bindevæv PDF

## Fibrillært Bindevæv - The two main fibril types in connective tissue are collagenous and elastic. - If collagenous fibrils dominate, the tissue is called collagenous connective tissue. - If elastic fibrils dominate, the tissue is called elastic connective tissue. - There will always be cells and...

## Fibrillært Bindevæv - The two main fibril types in connective tissue are collagenous and elastic. - If collagenous fibrils dominate, the tissue is called collagenous connective tissue. - If elastic fibrils dominate, the tissue is called elastic connective tissue. - There will always be cells and amorphous ground substance in connective tissue. - However, the fibrils are the most prominent. ### Fibrillært Kollagent Bindevæv - This is more widespread than any other connective tissue. - It plays a major role in most organ systems. - If the collagenous fibrils form a loose network, the tissue is called fibrillært kollagent løst bindevæv. - In figure 26, collagenous fibril bundles form a loose network. - There are a few, scattered elastic fibrils and cells. - The amorphous ground substance is reddish and lies between the fibrils and cells. - This is often referred to as simply loose connective tissue, referring to the fibrillært kollagent løst type. ### Fibrillært Kollagent Fast Bindevæv - If the collagenous fibril bundles lie very close together, the tissue is called fibrillært kollagent fast bindevæv. - The tightly packed fibril bundles make this type of tissue difficult to tear. - The tightly packed fibril bundles can be arranged in two ways: - Tight and irregular - Tight and regular - In figure 27, the fibrils are tightly packed and irregularly arranged. - This type of connective tissue makes up the dermis and mucous membrane lining. - In figure 28, the fibril bundles are tightly packed and regularly arranged. - This type of connective tissue makes up tendons, ligaments, and many membranes. - This includes the membrane surrounding bones and the tendon in the eye. ### Fibrillært Elastisk Bindevæv - This tissue contains many elastic fibrils. - It is found in the larynx, but only in small amounts elsewhere in the body. - This tissue is less common than collagenous connective tissue. ### Cellulært Bindevæv - Embryonic connective tissue, mesenchyme, is found in embryos. - It consists of large numbers of star-shaped cells. - There is a small number of fibrils and amorphous ground substance. - In adults, adipose tissue is the best-known type of cellular connective tissue. - Adipose tissue is dominated by fat cells. - Reticular connective tissue is another important type. - It's found in lymph nodes and bone marrow. ### Fibrils - Fibrils make up the shape of the amorphous ground substance. - They are located between cells and are surrounded by amorphous ground substance. #### Types of Fibrils - **Collagenous Fibrils** - Thin filaments (under 0.5 µm in diameter) - Form bundles of varying thicknesses - Strong, flexible, and inelastic. - Colorless, but can be dyed in tissue preparations. - Appear faint red in hematoxylin-eosin stained preparations. - **Elastic Fibrils** - **Reticulin Threads** ### How Bundles of Collagenous Fibrils Appear - In figure 19A, a bundle of collagenous fibrils is shown. - The bottom half of the figure shows 'normal conditions' where the fibrils lie tightly packed together. - The top half of the figure shows the individual fibrils, with each fibril having a 'fixed' diameter (0.5µm) that does not vary significantly. - The diameters of the bundles do vary. - This can be seen in figures 26, 27, and 28. - The elastic fibrils are only present in small amounts in collagenous connective tissue. - But, for the connective tissue to be properly called elastic connective tissue, elastic fibrils need to dominate. - Figure 58 shows an example of elastic connective tissue (in this case, in an elastic artery). - Elastic connective tissue does not have subdivisions like collagenous connective tissue. - This tissue can be found in different modifications. ### General Notes on Cellular Connecive Tissue - Cellular connective tissue is dominated by cells. - The cell density is not as high as epithelial tissue. - But its cell density is higher than in other types of connective tissue.