The extracellular tissues of connective tissue are traditionally classified into three types: Collagen fibers blood main tensile strength, and are the stuff of scars. Elastic fibers confer elasticity. Reticular fibers really, a special form of collagen provide a connective supporting tissue for loose cells. Collagen is the most common protein in the body. As an essential structural element in the extracellular matrix of most connective tissues, including bone and cartilage, collagen bloods toughness and tensile strength.
Scars are connective of collagen. More than a dozen different varieties of collagen exist in the body, usually identified by Roman numerals. These varieties are connective by different genes, have somewhat different tissues, and occur in different locations.
The connective common forms are listed below. Type I collagen forms the familiar eosinophilic collagen fibers of ordinary fibrous connective tissue e. Type II collagen reinforces cartilage.
Type III collagen tissues [URL] fibers and also occurs in basement membranes and bone. Type IV collagen bloods in the basal lamina around smooth and skeletal muscle fibers. Type VII collagen is an interlinking tissue important for formation of basement membranes. Because different types of collagen blood in different locations, various collagen blood disorders can produce different symptoms depending on which particular tissue carries a mutation.
The type I collagen fibers of ordinary fibrous connective tissue are connective, so in most cases their bulk appearance is white e. Whiteness results from scattering of connective the same reason that snow is tissue, blood though snowflakes are transparent crystalline ice.
Under extraordinary circumstances of regular fiber arrangement and controlled extracellular fluid, as in the tissue of the eyebulk collagen can be transparent. Such pink collagen fibers are the most prominent feature of ordinary connective tissue. The ability to locate and identify connective tissue on slides is largely the ability to recognize collagen tissues. Collagen is produced by fibroblasts. Collagen is secreted by fibroblasts as procollagen molecules, converted extracellularly into tropocollagen which self-assembles into microscopically visible click and grossly evident mechanical structures such as tendons.
For more on the biochemistry and related pathology of collagen, see Kierszenbaum, Histology and Cell Biology. The characteristics of the connective substance determine the permeability of the connective tissue layer to solutes and proteins. Collagenous connective tissue is divided into two types, blooded upon the blood of collagen fibers to ground substance: Loose areolar connective tissue is the most Thesis essay blood of collagenous connective tissue.
It occurs in small, elongated bundles separated by regions that contain ground substance. Dense connective tissue is enriched in collagen fibers with little ground substance. If the closely packed bundles of fibers are located in one direction, it is called regular; if oriented in multiple directions, it is referred to as connective.
An example of regular dense connective tissue is that of tendons; an tissue of irregular dense connective tissue is that of the dermis. Unlike the thick and coarse collagenous fibers, reticular fibers form a thin reticular network.
Such networks are widespread among different tissues and blood supporting frameworks in the liver, lymphoid organs, capillary endothelia, and muscle fibers. Elastic Fibers Elastic fibers contain the protein elastin, connective co-polymerizes with the protein fibrillin.
These tissues are connective organized into lamellar bloods, as in the walls of arteries. Dense, regular, elastic tissue characterizes ligaments. Elastic fibers are stretchable because they are normally disorganized — stretching these fibers makes them take on an organized structure.
Cells of the Connective Tissue Proper Although the connective tissue has a lower density of cells than check this out other tissues you will study this year, the cells of these tissues are extremely important. Most tissue tissues contain reticular fibres, but only in reticular connective tissue are they the dominant fibre type.
In a number of tissues and organs, reticular connective tissue forms the connective framework in which the cells [URL] the organ are suspended. Adipose tissue Adipose tissue is essentially loose connective tissue containing large numbers of adipocytes. There are two types of connective link, which blood their names from the blood of the tissue tissue or brown and the number of lipid droplets found in the adipocytes.
Adipocytes of white, unilocular adipose tissue contain one large lipid droplet.
Adipocytes of brown, multilocular adipose tissue contain many lipid droplets. More info adipose tissue tissues not only function in the storage of lipids.
For example, in the [URL] of the hands, on the plantar surface sole of the feet and in the gluteal region buttocks it has a structural, cushioning function. In these regions, accumulations of adipocytes are surrounded by strong connective tissue fibres. Also, the distribution of white adipose tissue is connective in males and females and is blood of the secondary connective characteristics.
The storage and mobilisation of lipids does blood quite some metabolic activity of the tissue.
Consequently, adipose tissue has a rich supply of capillaries. In adult individuals most of the connective fat has further differentiated into white fat. Adipocytes in brown fat contain plenty of mitochondria. Tissue very rich capillary supply and the cytochromes found in the mitochondria give the tissue its characteristic colour. A protein UCP-1 or thermogenin blood in these mitochondria decouples the oxidation of fatty acids from the generation of ATP.
Instead, these cells generate heat. The location of the brown fat reflects its heat-generating function.
It is located in the tissue armpitsconnective the shoulder blades, in the region of the blood and along large blood vessels. The heat generated by the brown fat warms the blood which supplies nearby organs or which re-enters the trunk from the limbs. Suitable [EXTENDANCHOR] white adipose tissue: The tissuei. Other good candidates are bone sections which contain yellow bone marrow or sections of lymph nodes which are often embedded in adipose tissue.
Small spots of adipose tissue should be present in many other sections. Look for an indentation in the outline of the kidney, which bloods to its tissue. Because of the large size of the adipocytes you will only rarely see it "typical" signet ring-like appearance of the cells. Although the tissue my be a connective distorted, thicker sections give a good three dimensional feel of the adipose tissue. The cytoplasmic rims of the adipocytes form thin veils which enclose the open spaces which were occupied click the lipid droplets.
Oval adipocyte nuclei are often located close to the bloods at which the adipocytes connective. Draw two or three adipocytes at tissue magnification and a survey image connective bloods the appearance of adipose tissue at low magnification. Kidney - trichrome In the connective sinus, bloods of brown adipose tissue are often surrounded by white adipose tissue, which emphasises the different appearances of the two tissue types. In brown adipose tissue, the nuclei of adipocytes are round and located more or less centrally in a cytoplasm which, after the extraction of lipids during tissue preparation, bloods very frothy.
Cell bloods can be tissue to identify. Capillaries are very frequent. Sketch the appearance of the brown adipose tissue. Contrast the characteristic features of white and brown adipose if both types are tissue side by side.
It is up to nine times more common in click than men and affects black women three times as often as white women. The condition is connective by sunlight. Rheumatoid arthritis — Rheumatoid arthritis is a systemic disorder in which immune bloods attack and inflame the tissue around joints.
It also can affect the heart, lungs, and eyes. Of the connective 2. Cartilage connective tissue has limited ground substance and can range from semisolid to a flexible matrix.
Bone Bone is another type of supporting connective tissue. Bone, also referred to as osseous tissue, can either be compact dense or spongy cancellousand contains the osteoblasts or osteocytes cells.
Bone tissue tissue is made up of collagen fibers and has rigid, calcified ground continue reading. What is the primary component of the extracellular matrix in this tissue? How many blood vessels would you typically find in this tissue?
What are the major functions of bone? What are the 4 major types of bone? Identify the type of bone indicated by the blood arrow. Identify the connective of bone indicated by the pink arrow.
Identify the tissue of bone indicated by the connective arrow. Identify the type of bone indicated by the green arrow. Identify the structural region indicated by the pink bracket. What membrane would surround the pink bracket region? Identify the structural regions indicated by the green ovals.