Tendinitis is routinely diagnosed through a clinical examination. In case of severe pain, X-rays can be examined to rule out the possibility of a bone injury. Severe cases of tendinitis can even tear loose a tendon. Surgical repair of a tendon is painful. Connective tissue in the tendon does not have abundant blood supply and heals slowly.
While older adults are at risk for tendinitis because the elasticity of tendon tissue decreases with age, active people of all ages can develop tendinitis. Young athletes, dancers, and computer operators; anyone who performs the same movements constantly is at risk for tendinitis.
Although repetitive motions are unavoidable in many activities and may lead to tendinitis, precautions can be taken that can lessen the probability of developing tendinitis. For active individuals, stretches before exercising and cross training or changing exercises are recommended. For the passionate athlete, it may be time to take some lessons to improve technique. All of the preventive measures aim to increase the strength of the tendon and decrease the stress put on it.
With proper rest and managed care, you will be back on the court to hit that slice-spin serve over the net. Watch this animation to learn more about tendonitis, a painful condition caused by swollen or injured tendons.
Two major forms of supportive connective tissue, cartilage and bone, allow the body to maintain its posture and protect internal organs. The distinctive appearance of cartilage is due to polysaccharides called chondroitin sulfates, which bind with ground substance proteins to form proteoglycans. A layer of dense irregular connective tissue, the perichondrium, encapsulates the cartilage.
Cartilaginous tissue is avascular, thus all nutrients need to diffuse through the matrix to reach the chondrocytes. This is a factor contributing to the very slow healing of cartilaginous tissues.
The three main types of cartilage tissue are hyaline cartilage, fibrocartilage, and elastic cartilage Figure. Hyaline cartilage , the most common type of cartilage in the body, consists of short and dispersed collagen fibers and contains large amounts of proteoglycans.
Under the microscope, tissue samples appear clear. The surface of hyaline cartilage is smooth. Both strong and flexible, it is found in the rib cage and nose and covers bones where they meet to form moveable joints.
It makes up a template of the embryonic skeleton before bone formation. A plate of hyaline cartilage at the ends of bone allows continued growth until adulthood. Fibrocartilage is tough because it has thick bundles of collagen fibers dispersed through its matrix.
Menisci in the knee joint and the intervertebral discs are examples of fibrocartilage. Elastic cartilage contains elastic fibers as well as collagen and proteoglycans. This tissue gives rigid support as well as elasticity. Tug gently at your ear lobes, and notice that the lobes return to their initial shape.
The external ear contains elastic cartilage. Bone Bone is the hardest connective tissue. It provides protection to internal organs and supports the body. Both components of the matrix, organic and inorganic, contribute to the unusual properties of bone. Without collagen, bones would be brittle and shatter easily. Without mineral crystals, bones would flex and provide little support.
Osteocytes, bone cells like chondrocytes, are located within lacunae. The histology of transverse tissue from long bone shows a typical arrangement of osteocytes in concentric circles around a central canal. Bone is a highly vascularized tissue. Unlike cartilage, bone tissue can recover from injuries in a relatively short time. Cancellous bone looks like a sponge under the microscope and contains empty spaces between trabeculae, or arches of bone proper.
It is lighter than compact bone and found in the interior of some bones and at the end of long bones. Compact bone is solid and has greater structural strength. Blood and lymph are fluid connective tissues.
Cells circulate in a liquid extracellular matrix. The formed elements circulating in blood are all derived from hematopoietic stem cells located in bone marrow Figure.
Erythrocytes, red blood cells, transport oxygen and some carbon dioxide. Leukocytes, white blood cells, are responsible for defending against potentially harmful microorganisms or molecules. Platelets are cell fragments involved in blood clotting. Some white blood cells have the ability to cross the endothelial layer that lines blood vessels and enter adjacent tissues.
Nutrients, salts, and wastes are dissolved in the liquid matrix and transported through the body. Lymph contains a liquid matrix and white blood cells. Lymphatic capillaries are extremely permeable, allowing larger molecules and excess fluid from interstitial spaces to enter the lymphatic vessels. Lymph drains into blood vessels, delivering molecules to the blood that could not otherwise directly enter the bloodstream.
In this way, specialized lymphatic capillaries transport absorbed fats away from the intestine and deliver these molecules to the blood. View the University of Michigan Webscope to explore the tissue sample in greater detail. Visit this link to test your connective tissue knowledge with this question quiz.
Can you name the 10 tissue types shown in the histology slides? Connective tissue is a heterogeneous tissue with many cell shapes and tissue architecture. Structurally, all connective tissues contain cells that are embedded in an extracellular matrix stabilized by proteins.
The chemical nature and physical layout of the extracellular matrix and proteins vary enormously among tissues, reflecting the variety of functions that connective tissue fulfills in the body. Connective tissues separate and cushion organs, protecting them from shifting or traumatic injury. Connect tissues provide support and assist movement, store and transport energy molecules, protect against infections, and contribute to temperature homeostasis. Many different cells contribute to the formation of connective tissues.
They originate in the mesodermal germ layer and differentiate from mesenchyme and hematopoietic tissue in the bone marrow. Fibroblasts are the most abundant and secrete many protein fibers, adipocytes specialize in fat storage, hematopoietic cells from the bone marrow give rise to all the blood cells, chondrocytes form cartilage, and osteocytes form bone.
The extracellular matrix contains fluid, proteins, polysaccharide derivatives, and, in the case of bone, mineral crystals. Protein fibers fall into three major groups: collagen fibers that are thick, strong, flexible, and resist stretch; reticular fibers that are thin and form a supportive mesh; and elastin fibers that are thin and elastic.
The major types of connective tissue are connective tissue proper, supportive tissue, and fluid tissue. Loose connective tissue proper includes adipose tissue, areolar tissue, and reticular tissue. These serve to hold organs and other tissues in place and, in the case of adipose tissue, isolate and store energy reserves.
The matrix is the most abundant feature for loose tissue although adipose tissue does not have much extracellular matrix. Dense connective tissue proper is richer in fibers and may be regular, with fibers oriented in parallel as in ligaments and tendons, or irregular, with fibers oriented in several directions.
Organ capsules collagenous type and walls of arteries elastic type contain dense irregular connective tissue. Cartilage and bone are supportive tissue. Cartilage contains chondrocytes and is somewhat flexible. Hyaline cartilage is smooth and clear, covers joints, and is found in the growing portion of bones.
Fibrocartilage is tough because of extra collagen fibers and forms, among other things, the intervertebral discs. Elastic cartilage can stretch and recoil to its original shape because of its high content of elastic fibers. The matrix contains very few blood vessels. Bones are made of a rigid, mineralized matrix containing calcium salts, crystals, and osteocytes lodged in lacunae. These fibers consist of closely packed thin collagen fibrils nm thick in ordinary tissues of mammals , and exhibit splitting and joining in altering the number of the fibrils to form a three-dimensional network as a whole.
Individual collagen fibrils i. During fibrogenesis, collagen fibrils are considered to be produced by fusing short and thin fibrils with tapered ends. Reticular fibers are usually observed as a delicate meshwork of fine fibrils stained black by the silver impregnation method. They usually underlie the epithelium and cover the surface of such cells of muscle cells, adipose cells and Schwann cells.
Electron-microscopically, reticular fibers are observed as individual collagen fibrils or a small bundle of the fibrils, although the diameter of the fibrils is thin about 30 nm and uniform. Reticular fibers are continuous with collagen fibers through the exchange of these collagen fibrils. In silver-impregnated specimens, individual fibrils in reticular fibers are densely coated with coarse metal particles, probably due to the high content of glycoproteins around the fibrils.
Elastic fibers and laminae are composed of microfibrils and elastin components. Observations of the extracted elastin have revealed that elastin components are comprised of elastin fibrils about 0.
The fibres can vary in diameter, and in the way in which they are 'woven' into a network. For example, in tendons, the fibres run parallel to resist forces in the direction in which the muscle produces force. In bone they are arranged in alternating parallel layers. Whereas GAGs are good at resisting compressive forces, fibres are good at resisting tensile forces. There are two main types of fibre; collagen, and elastin and fibronectin.
You may also come across Fibronectin which is a non-collagenous fibrous connective protein that helps cells to stick to the extracellular matrix. A diagram of a collagen molecule. Collagen is the most common fibrous protein in the ECM, and it isi important for resisting tensile forces.
It is secreted by fibroblasts as procollagen , and amino acid residues at the ends of the protein are cleaved off outside the cell to form collagen, which then aggregates into fibres, etc. This prevents formation of large fibres in the cell would not be good for the cells! Collagen consists of three protein chains which wrap around each other in a helical arrangement.
The collagen molecules are often crosslinked , for extra strength - tensile strength. About 15 kinds of collagen are known. This type is found in bone, skin, tendon, ligaments, cornea etc.
Type VI helps to anchor basal lamina of skin to underlying connective tissue.
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