connective tissue. connective tissue is one of the basic tissues which gives structural and...
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CONNECTIVE TISSUE
Connective tissue is one of the basic tissues which gives structural and metabolic support to
the organ and other tissue of the body.
It connects other tissues.
Functions
• Support Structural & Mechanical• Packing Fills spaces, Shape to the
organ• Storage Adipose tissue: energy
Loose areolar CT: water & Electrolytes• Transport Medium for Nutrients &
Metabolic wastes• Repair Fibroblasts:matrix and fibres• Defense Cells: Phagocytosis or
Antibodies
Cells of Connective Tissue • A. Fixed cells (intrinsic cells) 1.Fibroblast &
Fibrocytes 2. Mesenchymal cells 3. Adipocyte
4. Fixed macrophages• B. Free cells (extrinsic
cells/Wandering Cells) 4.Free Macrophage 5. Mast cell 6. Plasma cells 7. Leucocytes
Function
• Fixed Cells: Production & Maintenance of Extracellular Matrix.• Free Cells:Tissue reaction to injury
or invasion of Microorganisms.
Fibroblast
• Most commonly seen• Fusiform with slender cytoplasmic process• Large oval nucleus,• Responsible for fiber production• Old cells are fibrocyte, • Contractile Cells are myofibroblast
Adipocytes
• Store lipid• Appears as empty
space• Incapable to division• Aggregate in adipose
tissue with reticular fibre
Mesenchymal cells
• Undifferentiated cells• Stellate in shape, • Cytoplasmic process,• Pluripotenant cell• Near blood vessels as
Advential cell
Macrophages (Histiocytes)• Free and Fixed type,• Fixed Cells-• Irregular Shape • filopodia process, • Dark indented eccentric
nucleus, • Derived from monocyte • Involved in phagocytosis• Fused to form giant cell.• Free Cells- rounded, no
filopodia
Plasma cells
• Oval basophilic cells, • Eccentric nucleus • Heterochromatin as cartwheel
nucleus• Derived from B lymphocyte • Produces immunoglobulin• Antibody collected as Russell
body. • Present in respiratory tract and
gastrointestinal tract
Mast cell
• Round or Fusiform Shaped• Mostly along blood vessels,• Metachromatic granules in
cytoplasm, • Granules have Histamine or
Heparin, • Look like basophil, so called as
connective tissue basophil . • Connective tissue mast cell –
heparin granule, present in skin. • Mucosal mast cell –small,
present in lamina propria of git and respiratory tract
Leucocytes-
. Granulocytes-Neutrophils, Esinophils,
Basophiles. Agranulocytes
Lymphocytes, Monocytes
Collagen Fibre
• White colour when fresh• Do not branch,wavy• present in bundle• Collagen protein forms
Fibres• Fibres composed of fibril
made of microfibrils• Micro fibrils made up
tropocollagen-striations• Synthesized by fibroblast
Collagen• Tropocollagen is
synthesized by fibroblasts and released into extracellular space where they get polymerized to form collagen fibrils
• Collagen on boiling gives gelatin
• More than 25 types are present
Collagen is also synthesized by
• Chondroblasts: in collagen
• Osteoblasts : in bone
• Smooth Muscle: in blood vessels
• Odontoblasts: in the tooth
Types
• Type1-bones ,tendons, dermis etc
• Type2-cartilage
• Type3-reticular fibres
• Type4-basement membrane
• Type5-blood vessels
Elastic fibre
• Yellow in color when fresh• Composed of elastin protein• Singly present• Branched and anastomose
forming a network• Can be stretched (one and a
half times)• Synthesized by fibroblast
and smooth muscle cells in blood vessels
• Found in ligamentum flava, ligamentum nuchae, large arteries
Reticular fibre
• Structurally similar to collagen fibres
• Are very thin Immature collagen fibre
• Actively branch to form delicate network therefore named Reticular
• Form supportive framework of lymphoid tissue
• Stained black by silver salts (argyrophillic)
• Composed of Collagen Type III
Ground Substance
• Transparent & Homogeneous• Fills spaces between cells and fibres• Acts as amoleculer sieve facilitating diffusion
between blood and tissues.• Composition:• Mucopolysaccharides• Structural Glycoproteins• Water & Electrolytes
• Mucopolysaccharides(Glycosaminoglycans): Consistency & viscocity of GS, serves as a physical barrier in spreading infection. Examples: Hyaluronic Acid & Heparan Sulphate.
• Structural Glycoproteins: Adhesion of cells to the neighbouring cells. Examples: Fibronectin(Dermis), Chondronectin(in Cartilage) & Laminin(in basement membrane)
• Water & Electrolytes: Maintenance of Fluid balance.
Ground substance
• Polysacchrides - hexurate or galectose
• Carbohydrate protein complex (proteoglycanes)-• 1- mucopolysacchride (glucosaminoglycanes)• NonSulphates-chondroitin and hyluronic
acid • Sulphates - chondotinesulphate, heparitine
sulphate, keratohyline• 2- glycoprotienes- fibronectine(dermis),
chondronectine (cartilage), laminin (b.m)• water & minerals
Classification
Connective tissue1.Ordinary connective tissue- Loose connective tissue -Dense connective tissue Regular Irregular2.connective tissue with special properties Adipose tissue Mucoid tissue Reticular tissue Pigmented tissue3.Scleral connective tissue -Bone -Cartilage4.Lymphoid and heamopoietc connective tissue
Examples• Loose areolar connective tissue-
subperitoneal tissue, endomysium, lamina propria
• Dense collagenous C TRegular- tendon, ligament, aponeurosisIrregular-dermis of skin
• Connective T with special propertiesElastic-Ligamentum nuchaeMucoid/ Embryonic tissue- Wharton’s jellyReticular Tissue- Stroma of lymphoid organ
MCQ
• Large number of elastic fibres are present in• 1. Tendon• 2. Ligamentum Nuchae• 3. Basement Membrane• 4. Aponeurosis
MCQ
The fat cells of Multilocular adipose tissue (Brown fat) is characterized by the presence of1.Spherical central nucleus and many lipid droplets. 2.Flat peripheral nucleus and single lipid drop3.Flat central nucleus and single lipid droplet4.Thin rim of cytoplasm