Connective Tissue
They are the most abundant and widely distributed tissue type in the body. Connective tissues run the gamut for vascularity. Some tissues are avascular (Cartilage), some are poorly vascularized (dense connective tissue), and some have rich blood supplies (bone).هستو \ عمليد . ايوب 23\10\2017 18
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Connective Tissue
Connective tissues can be rigid (bone), flexible (adipose), or fluid (blood). Unlike the tightly packed Epithelial tissues, living cells in connective tissues are separated by a non-living extracellular matrix (Ground Substance and Fibers). Due to the matrix, connective tissues are able to bear weight, withstand tension, and endure abuses that no other tissues could tolerate..
Connective Tissues are made of three main components: Ground Substance Fibers Cells Connective Tissues have many specific functions. Its major functions include Binding and support Protection Insulation Transportation of substances.
Connective Tissue Facts – Ground Substance The ground substance is the unstructured material between cells that contains the fibers. The ground substance holds large amounts of fluid and serves as a medium through which nutrients and other substances can diffuse between blood vessels and the cells.
Ground Substance
Ground SubstanceCo. T. Facts – (1) Fibers There are three types of fibers prevalent in Connective tissues A.) collagen fibers – are wide and wavy in appearance and generally stain pink. 79% of the protein in the body is collagen.B.) elastic fibers – are thin flexible fibers made from the protein elastin, that generally stain black.C.) reticular fibers – are actually thin collagen fibers. They have a spider web appearance and appear black under stain.
Fiber Types
Reticular FibersCollagen Fiber
Elastic Fiber
Other Cells Present
Type of Connective Tissue Immature Cell Mature CellFibrocyteCartilage Chondroblast Chondrocytene Blood Hematopoietic Stem Cell Blood cell (macrophages)Connective tissue is also home to many other cell types including Fat Cells, and mobile cells that migrate into the connective tissue from the blood stream, ie. mast cells and macrophages.Areolar Connective Tissue
Each major type of connective tissue has its own fundamental cell type in both immature and mature forms Structure- gel like matrix with all three fiber types present. Three cell types present Mast cells Macrophages fibroblastsConnective Tissue Proper - Areolar Connective Tissue
Mast Cells – produce heparin and histamine.Macrophages - are “big eaters”. They eat bacteria and dead or dying cells.Fibroblasts – fiber builders.Co. T. Proper - Areolar Connective Tissue
Location – Found between the skin and muscle.Also found between musclesPackages organsSurrounds Capillaries.Areolar Connective Tissue is the most widely distributed connective tissue in the body. It serves as a kind of packaging material between other tissues. Collagen Fiber
Elastic Fiber
Fibroblast
Connective Tissue Proper - Areolar Connective Tissue
Function – Wraps and cushions organs.Macrophages phagocytize bacteriaHolds and conveys tissue fluid.Connective Tissue Proper – Adipose Tissue Location – Found around organs, joints, surrounding the eyeball, within the abdomen.Structure – Adipocytes (fat filled cells) are ring shaped cells filled with tryglycerides.Has a chicken wire appearance.
Connective Tissue Proper – Adipose Tissue Function – Shock absorptionEnergy StorageProtectionInsulation
Co.T. Proper -Reticular Tissue
Structure : A network of reticular fibers with macrophages interspersed. Location: Spleen; Lymph nodes and liverMacrophage
Reticular Fibers
Co. T. Proper- Reticular Tissue
Function In Lymph Nodes – macrophages devour bacteria, viruses and cancer cells.In Spleen – macrophages break down dying RBC’s.In Liver – macrophages (Kupffer cells) devour bacteria.This tissue forms a soft internal skeleton that supports other cell types.Connective Tissue Proper – Dense Regular Connective Tissue Structure – Parallel collagen fibers.Dark colored fibroblasts interspersed.
Co. T. Dense Regular
Location – In tendons and ligaments.In scar tissueaponeuroses FibroblastCollagen Fiber
Connective Tissue Proper – Dense Regular Connective Tissue Function – Provide high tensile strength in one direction. Attached muscles to bone, bone to bone
Hyaline Cartilage
Structure – The chondrocytes (cells) lie in lacunae (spaces around cells).There is a large amount of extracellular matrix which is bordered on either side by the perichondrium. PerichondriumChondrocyte
Lacunae
Hyaline Cartilage
Location - Forms most of the embryonic skeleton. Covers the ends of long bones. Costal cartilage Nose Trachea LarynxHyaline Cartilage
Function –Provides a smooth surface for joints to move over.Resists compression and provides flexible support. ChondrocyteLacunae
Extracellular matrix
Elastic Cartilage
Structure- Similar to Hyaline cartilage with the exception of the elastic fibers in the matrix.Elastic Cartilage
Location – EarsEpiglottis Elastic FiberElastic Cartilage
Function –Maintains shape of a structure but is also extremely flexible. ChondrocyteLacunae
Fibrocartilage
Structure – Thick collagen fibers predominate the matrix. Chondrocytes are interspersed among the fibers.Fibrocartilage
Location – Intervertebral DiscsPubic SymphysisMenisci of the knee ChondrocyteCollagen Fiber
Fibrocartilage
Function – Shock absorptionSmooth tough support ChondrocyteCollagen Fiber
Compact Bone
Structure –Bone is highly vascularHaversian canals contain an artery vein and nerveOsteocytes reside in lacunae within the matrixConsists of a hard calcified matrix Canaliculi branch away from the haversian canal to take nutrients to the osteocytes Haversian CanalOsteocyte in Lacunae
Canaliculi
Compact Bone
Location –in compact boneThe Haversian system is only found in compact boneSpongy bone has osteoblasts and osteocytes but no Haversian systemsCompact Bone
Function – Provides stability to the body and allows for movement with attachment of muscles. Lamella.
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Blood
Structure – Red (Erythrocytes) and White (Leukocytes) blood cells.There are also platelets (Thrombocytes)Cells are immersed in a fluid matrix (plasma) ErythrocyteThrombocyte
Leukocyte (Neutrophil)