Connective tissue Connective tissue proper Cartilage Bone dancing%20skeleton%20r 250px-Tissue-fig-4 Origine and function of c.t. * Origin – embryonic mesenchyme * Functions: • - nutritive (blood vessels and • difusion of nutriens) • - protective – immunocompetent • cells and antibodies production - connective – between different tissues • - mechanical (supporting and • mechanical protection of organ – in skull, • thorax, pelvis) Connective tissue types * C.t. proper * Cartilage * Bone •___________________________________ * general structure: • - cells • - intercellular fibers • matter ground amorphous • substance http://casweb.cas.ou.edu/pbell/Histology/Images/Cartoons/connective.GIF Image116 Connective tissue proper - cells •FIXED CELLS * Fibroblasts, fibrocytes * Reticular cells * Fat cells (univacuolar, multivacuolar) * Pigment cells * Undifferentiated cells * * Fibroblasts, fibrocytes Schema Fibroblast s48100xf Reticular cells •Network of cell processes + reticular fibers collagen III 59_08 Adipose (fat) cells •univacuolar multivacuolar •(white adip.c.t) (brown adip.c.t.) Lipid droplets Pigment cells * * * * * * * * * melanocyte boc0980567a05 neuroectodermal origin Connective tissue proper - cells •MOBILE CELLS * Histiocytes Þ macrophages * Mast cells * Plasma cells • & * Leukocytes • * Histiocytes ðmacrophages (belong to monocyte-macrophage system) •phagocytosis macrophage_prescott 14_28 4%20fibroblasts cctmp Mast cells •heparin, histamin •– inflamation mediators 06_010 areol4_s Plasma cells (B-ly are precursors) •antibodies (immunoglobulins) •production 06_016 Rough ER s48100xf cctpc Intercellular (amorphous) ground substance •homogenous semifluid material * glycosaminoglycans (hyluronic acid, chondroitinsulphate, dermatansulphate, keratansulphate, heparansulphate) * glycoproteins (fibronectin, laminin) – cell adhesive function * H2O, ions • Fibers * collagenous * reticular * elastic skin_30_02 image004 Collagen fibers * „white fibers“, solid and strong, but not elastic * 1 – 20 mm Ø * arranged into bundles * collagenase – digestive enzyme * in LM – acidophilic (pink in HE) dirr Collagen fibers • [collagen_fibers.jpg] 061114190020 s31100xd 64 nm Collagen fiber types •Collagen Type I –most ubiquitous (cf.) •Collagen Type II –in cartilage •Collagen Type III –reticular fibers •Collagen Type IV –"amorphous collagen" without a fiber structure, synthesized by epithelial cel •About 40 types of collagen are known Reticular fibers * contain type III collagen * form a fine meshwork (reticulum) - a supporting mesh in soft tissues such as liver, bone marrow, and lymph organs * they are argyrophilic (silver staining) * 0.5 – 2 mm Ø ct16.gif (35137 bytes) Elastic fibers * „yellow fibers“ - bundles of protein (elastin) produced by fibroblasts and smooth muscle cells in blood vessels. * these fibers can stretch up to 1.5 times their length, and snap back to their original length when relaxed. * are branched and wavy * spetial staining with orcein or resorcin-fuchsin * 15-Elastic%20Fibers%20-%20Mesentery C.t.proper classification * several types of c.t.proper: classification depends on cells, fibers and ground substance quantity and arrangement * abundant ground subst.– „soft tissue“ * abundant fibers – „hard tissue“ * fibers can be arranged (ir)regularly CTP classification (types of c.t.) * Mesenchyme * Jelly-like c.t. (Wharton´s jelly) * Collagenous c.t. areolar (loose) • dense irregular • regular * Reticular c.t. * Elastic c.t. * Adipose c.t. white fat • brown fat * * * * 1. Mesenchyme 2. jelly-like c.t. •embryonic c.t. • •umbilical cord, dental pulp • cctm mesench Talapoin07 you too can be wealthy cctm 3a. collagenous loose (areolar) c.t. • • 25_09 connective%20tissue,%20loose,%20areolar * 3b. collagenous dense c.t. irregular regular • • • • • dirr t20 whitect3 cctdict 4. reticular c.t 5. elastic.c.t. •membranes in blood •vessels wall(orcein) • •supporting tissue in •lymph organs (impregn.) • cctrct 46 ct16.gif (35137 bytes) 6. adipose tissue brown fat white fat •fetal adipose tissue •(thermoregulation) • bwfat * brownfat whitefat Light microscopy * Occular magnif.: 10x * Objectives magnif. 4x, 10x, 40x * Total magnif.: 40x, 100x, 400x * Don´t use immersion objective! * Slide cover slip must be situated up to the lens of objective 10x Supporting connective tissue * Cartilage * Bone Cartilage - general characteristic - * Avascular tissue (without blood vessels); nutrients are transported to the cells by diffusion from perichondrium * Perichondrium* – dense connective tissue capsule with blood vessels * Mesenchymal origin * •* Is not present on the articular surfaces of cartilage and on the surface of fibrocartilage • General structure of the cartilage * Cells – chondrocytes in lacunae * Intercellular matter: -ground substance chondroitinsulphates • chondronectin •- fibers (collagenous or elastic) Cartilage cells: chondroblasts, chondrocytes * in lacunae * produce intercellular matter: - collagen or elastic fibers - ground substance: 1) main glycosamino-glycans are chondroitinsulfates, keratansulfate = acid substances cause basophilia of cartilage, 2) glycoprotein chondronectin (increases adhesion of cells and matrix) * cells are involved in cartilage growth: - interstitial growth (isogenic groups) - appositional growth (from perichondrium) * * * • Hyaline cartilage (example: free surfaces of joins, epiphyseal growth plate) * Chondrocytes form isogenic groups (in basophilic capsule) * Collagenous fibers form bundles * Ground substance is abundant and covers the fibers hyaline%20cartilage hyc40he 1-Hyaline%20Cartilage%20-%20Trachea Elastic cartilage (example: auricle, epiglottis) * Chondrocytes in lacunae are dispersed: NO isogenic groups * Elastic fibers * Ground substance S37 Elastic%20cartilage%20photo%20EDITED elastic ccec3 Fibrocartilage (example: symphysis, intervertebral discs) * Small and flattened chondrocytes * Thick bundles of collagenous fibers * Small amount of ground substance * No perichondrium tendo-02-l ccfts Bone tissue •Organic component * Cells * Collagenous fibers * Ground substance is mineralized •Inorganic component * Minerals – hydroxyapatite crystals • Ca10(PO4)6(OH)2 • * bone Intercellular matrix * Organic component: - collagen fibers (collagen type I) - ground substance: 1) main glycos-aminoglycan are chondroitin-sulfate, keratan-sulfate, 2) fibronectin, osteopontin (increase adhesion of cells and matrix), osteocalcin (binds Ca) * Inorganic component: crystals of hydroxyapatite • Bone cells •osteoprogenitor cells •osteoblasts •osteocytes •osteoclasts basic-bone-biology-1-395x134 f6-6a_types_of_cells_in_c spongy2 on the surface of the bone inside of the bone matrix (in lacunae) osteoblasts -on the surface of bone (epitheloid arrangement) -synthesize non-mineralized intercellular matrix = osteoid (ground substance + collagen) -periosteal osteoblasts – growth of bone by apposition 69_03 s2340x2 osteocytes -osteoblasts entrapped in mineralized bone matrix = osteocytes (cytoplasmic processes in canaliculi ossium Þ striation of bone lamellae) -transport of minerals from blood into the matrix 69_03 figure1 osteoclasts -in Howship´s lacunae -large multinucleated cells (up to 50 nuclei) – arrise by fusion of monocytes -produce acid phosphatase – enzyme involved in bone resorption during ossification, bone remodeling or reparation 69_05 ocl41he cbohl Periosteum – endosteum •Periosteum •dense c.t.capsule attached to •bone by Sharpey's fibers •(collagen); is composed of •two layers: 1)outer fibrous •layer of dense irregular c.t. •and 2)inner cellular layer •composed of cells that give •rise to osteoblasts. • •Endosteum •thin layer of connective tissue •containing osteoprogenitor •cells and osteoblasts * * * * * * * pos20he s2340x2 Periosteum – endosteum 69_07 Types of bone tissue • • Fibrillar (woven) Lamellar spongy (cancellous) compact Bone types A) fibrillar bone – „primitive“ •Arrise by primary ossification and •is transformed into the compact bone •during secondary ossification • • •Forms tuberositas ossium * • • • osteocytes Bundles of collagen fibers Bone types B) lamellar (cancellous) bone cancellous_bone spongy - compact long_bone Spongy (trabecular) bone * Image:Spongy bone - trabecules.jpg compact bone •collagen fibers in •mineralized ground •substance form •lamellae, which are •arranged as: * Haversian lamellae = osteon * interstitial lamellae * circumferential lamellae (inner, outer) * image002 Lab_1b-22a OSTEON: 1 – Haversian canal contains 2, 3 – blood vessels, 4 – nerves in loose connective tissue; 5 – lamellae 7 – osteocytes in lacunae (6) 8 – cytoplasmic processes in canaliculi ossium Osteon 74_02 74_04 74_03 grbone2 plywood1 Outer circumferential lamellae Haversian system Inner circumferential lamellae Haversian canal Interstitial lamellae Ossification – bone formation * PERIOSTEUM contains blood vessels and osteoprogenitor cells Þ osteogenic potential * osteoblasts (producce inter- • cellular matrix OSTEOID * Osteoid + minerals (from blood) = OSSEIN * Osteoblasts entrapped in ossein Þ osteocytes, • (osteocytes + ossein = BONE) * The result of primary ossification is fibrillar bone * Resorption, remodelation of fibrillar bone by osteoclasts * The result of secondary ossification is compact bone (are involved in destruction of woven bone) Ossification types * Intramembranous ossification • - bone develops in mesenchymal membrane Þ flattened bones * Endochondral ossification - bone develops on a cartilage model Þ long bones * • Intramembranous ossification •Formation of bone directly from mesenchyme. • * Increased vascularity of mesenchyme * Mesenchyme cells Þ osteoprogenitor cells Þ osteoblasts * Osteoblasts produce osteoid and transform into osteocytes. * Periosteum + endosteum (dura mater in skull) • • • NEUROCRANIUM and other flat bones osteogenesis1 11_02 mezenchymocytes osteocytes Endochondral ossification * PRIMARY OSSIFICATION CENTER: Occurs in the center of the diaphysis, and extends toward both epiphyses. * SECONDARY OSSIFICATION CENTER: in the center of the epiphyses. * EPIPHYSEAL PLATE: is hyaline cartilage which alllows bone growing in the length. * bone Endochondral ossification • * Perichondrium arround diaphisis transforms into periosteum (fibroblasts Þ osteoprogenitor cells) * Blood vessels invade the cartilage and bring osteoprogenitor cells, blood cells, bone marrow cells, macrophages, endothelial cells. * Ca and other ions are transported by blood and intercellular matrix around the chondrocytes is calcified – nutrients cannot difuse to them – cells degenerate and die * • • Endochondral ossification * after chondrocyte death mineralized intercellular matrix forms spicules (rests of cartilage) * they are occupied by osteoblasts producing osteoid * osteoid surrounds osteoblasts and is mineralized by ions from blood; osteoblasts Þ osteocytes * primary ossification = fibrillar bone * resorption - osteoclasts * secondary ossification = lamellar bone • im100001 OSSIFICATION ZONES * RESERVE ZONE: normal hyaline cartilage * PROLIFERATIVE ZONE: chondrocytes in columns * ZONE of HYPERTROPHY: enlarged chondrocytes * CALCIFIED ZONE: (different staining of intercellular matter in light microscope) * „LINE of erosion“ – imaginary line * OSSIFORM ZONE: spicules, osteoid, ossein in regions of bone formation plytka_wz Cartilage Bone •Slides: * Hyaline cartilage (28. Trachea, HE) * Elastic cartilage (26. Eoiglottis, HE) • (27. Elastic cartilage, orcein) * Lamellar bone (… * Endochondral ossification (… • •Atlas EM: NM009b remodel NM006b 69_08 Cut image Cut image Cut image Cut image Bone junctions - joints * SYNARTHROSES: Poorly moveable (fibrous) or immobile joints. * Syndesmosis: Bones connected by dense fibrous connective tissue, as in SKULL SUTURES * Synchondrosis: Bones connected by cartilage, as in the PUBIC SYMPHYSIS. * Synostosis: bones connected by bone tissue, as in the PELVIS –DIARTHROSES: Movable joints * Articular Cartilage made of hyaline cartilage, without perichondrium, covers the moving bone-ends. * Joint Capsule is continuous with the periosteum. * Synovial Membrane lines the joint capsule. It secretes synovial fluid into the joint space. * * Diarthrosis stevensjoint2 skeleton90 Thanks for attention full endochon cartbone mbonelo (Intra)membranózní osifikace * Mezenchym + vaskularizace: ð • ð : produkce • * Osteoblasty + osteoid ï mineralizace: osteoblasty ð • mezenchymocyty osteoprogenitorní bb. osteoblasty you too can be wealthy Pojivové tkáně - 49 Chondrogenní osifikace A: chrupavčitý model kosti: 1- epifýza, 2, střed diafýzy B: periostální manžeta (z perichondria) invaze krevních cév s osteoklasty (na čele ) a osteoprogenitorní- mi bb. (podél cév ) you too can be wealthy Enchondrální osifikace (chondrogenní) Pojivové tkáně - 50 Chondrogenní osifikace you too can be wealthy A: hypertrofie a kalcifikace chrupavky B: detail (A) 1 - periost 2 – osteoklasty 3 – osteocyty v kostěné manžetě pod periostem 5 – monocyty 6 – osteoprogen. bb. Pojivové tkáně - 53 Chondrogenní osifikace you too can be wealthy Pojivové tkáně - 52 Chondrogenní osifikace you too can be wealthy Zóna normál. hyalinní chrupavky Zóna proliferující chrupavky Zóna hypertrofické chrupavky Zóna kalcifikující chrupavky 2 – osteoklasty 4 – primární kost s osteocyty 5 – osteoblasty 6 – osteoid (pod osteoblasty) 9 – kapiláry nrm2125-f3 you too can be wealthy Pojivové tkáně - 55 Chondrogenní osifikace you too can be wealthy Pojivové tkáně - 56 Chondrogenní osifikace you too can be wealthy Pojivové tkáně - 60 Chondrogenní osifikace you too can be wealthy Endochondral_Ossification_ you too can be wealthy Endochondral_Ossification_Developing_Long_Bone_ Pojivové tkáně - 54 Chondrogenní osifikace you too can be wealthy Lamellar bone * basic-bone-biology-2-455x414 kost-2 bone f6-11l_endochondral_oss_c histology9 histology11 histology8 histology7 cortbone1 Ossification – bone formation * PERIOSTEUM contains blood vessels and osteoprogenitor cells Þ osteogenic potential * Osteoprogenitor cells Þ osteoblasts (production of intercellular matrix OSTEOID * Osteoid + minerals (from blood) = ossein * Osteoblasts entrapped in ossein Þ osteocytes, osteocytes + ossein = BONE * The result of primary ossification is woven bone * The result of secondary ossification is compact bone (osteoclasts are involved in destruction of woven bone) f6-10t_intramembranous__c