list all cells found in the connective tissueSolutionCOMPONE

Fibroblasts:

Structure:these are bulky and flat cells that contains branching projections. the nuclei is large and oval shaped with one or two conspicuous nucleoli.

Occurrence: mostly every connective tissues is comrised of fibroblasts.

Function:

• they maintain the structural integrity of the connective tissue, as they continuously secrete extracellular matrix proteins like collagens, glycosaminoglycans, and glycoproteins.
• they play critical role in wound healing.
• Proteoglycan,which is the main constituent of the ground substances in connective tissues is produced through fibroblasts.
• at the injured region injury, they produce new fibers.

Ground Substance:

a) Proteoglycans:

these are composed of core proteins. examples includes aggrecan, syndecan.

b) glycosaminoglycan:

ther are covalently bound to the proteoglycans. examples-dermatan sulfate, keratan sulfate, hyaluronan.

i) Hyaluronic acid:

jelly-like substance

responsible for lubrication of various joints of the body

assists in maintaining the shape of the eye balls. White blood cells, sperm cells, and some bacteria produce hyaluronidase, an enzyme that disintegrates hyaluronic acid, thus causing the ground substance of connective tissue to become more liquid.

ii) Chondroitin sulfate: structural component of cartilage and provides much of its resistance to compression, due to which it is used as a dietary supplement for treatment of osteoarthritis.

c) multiadhesive glycoproteins: links together parts of ground substance to the surface of cells,example fibronectin, which attaches to collagen fibers and ground substance, joining them to one another. Fibronectin also attaches cells to the ground substance.

Macrophages:

Structure: macrophags arises from monocytes.

shape: Macrophages also known as histiocyte, are not in regular shape and have short branching processes.

Occurrence: following fibroblasts, macrophages are present in enormously in loose connective tissue.

Types of macrophages:

Fixed macrophages: present at a particular tissue, for example alveolar macrophages (in the lungs) or spleenic macrophages (in the spleen).

Wandering macrophages:they have the ability to move throughout the tissue and congregate at sites of infection, inflammation to perform phagocytosis.

functions of macrophages:

• phagocytosis or cell eating, it is a type of endocytosis.
• engulf blood cells, bacteria, dead cells
• it is an important constituent of the reticuloendothelial system (RES) present in the spleen, liver and lymphatic system.

Connective Tissue Fibers:

a) Collagen fibers:

• this type of protein is abundantly found in our body.
• found in cartilage, tendons, bones, and ligaments, providing strenght and cushioning to the connective tissue.

b) Elastic fibers:

• they contain the protein elastin surrounded by a glycoprotein called fibrillin, which provides strength and stability. their width is lesser than collagen fibers.
• They branch and unite together to constitute a fibrous network within a connective tissue

c) Reticular fibers:

• they are less common
• thinner than collagen fibers
• forms interwoven framework in various organs.
• collagen arranged in thin bundles that are covered with glycoprotein,
• it supports the walls of blood vessels and form a network surrounding the cells in some tissues, eg areolar connective tissue, adipose tissue, nerve fibers, and smooth muscle tissue.
• Reticular fibers are abundantly present in reticular connective tissue.

Plasma cells:

Structure: they are small sized cells that arise from B lymphocyte( white blood cell). (1) Plasma cells have basophil cytoplasm and an eccentric nucleus; (2) Plasma cell have well-defined and clear perinuclear region of the cytoplasm which contains a large number of Golgi bodies.

Occurrence: ther are mostly found in connective tissues like gastrointestinal and respiratory tracts.

function:

• It plays key role in body’s immune response.
• Plasma cells deliver antibodies and proteins that attack or reduce the effect of foreign materials in the body.

Mast cells:

Structure: They are large cells (20-30µm) filled with basophilic granules that most of the time obscure the nucleus.

Occurrence: These are generally abundant around blood vessels. These are very much similar to the blood basophils. releases histamine, heparin and serotonin during inflammatory and allergic reactions.

function:

• plays importantrole in allergy and anaphylaxis
• mast cells play an important role in wound healing and defense against pathogens.

Adipocytes:

Structure: They are also called fat cells. their primordial structure resembles fibroblasts except they have abundant vacuoles of fat droplets.

Occurrence: present underneath to the skin and around organs like heart and kidneys. These are frequently found arranged near to small blood vessels.

functions: These cells store triglycerides the form of fat.

Leukocytes:

Structure: they contain nuclei. they can be granulocytes eg basophils, eosinophils, neutrophils, or agranulocytes eg monocytes and lymphocytes.

Occurrence: Eosinophils are extensively present throughout the respiratory, digestive tracts and in active mammary tissue.

functions: In normal condition, these are less-abundant in connective tissue. Whereas, in specific conditions they move from blood into connective tissues. For example neutrophils get together at region of infection and eosinophils move to region of parasitic invasions and involved in the allergic reactions.