Support Cells and the extracellular matrix (connective tissues)

Connective Tissue: loosely arranged cells and abundant stromaMatrix: stromaFunctions: Support Protection Transport Insulation Hematopoeitic Immunologic - vital function Tisue repair

Embryonic origin -mesoderm (primitive mesenchymal cell or stem cells)-malignant tumors are termed Sarcomas

Sarcoma - tumors in connective tissue; spread through blood vessel routes;chemotherapy and radiation resistantCarcinoma - tumors in epithelial origin;spread to lymphatic

CT tissue cells make up the fiber and the matrixFibers - thin hair like CLASSIFICATION OF CONNECTIVE TISSUE1. Adult CT (mature tissue)A. CT propera. Collagen/General (Basic;made by fibroblast) (fiber is Collagen type I) i. Loose (fibers are loose) - widely distributed, superficial and deep fascia,few collagen fibers, found underneath the skin ii. Dense (fibers are compact) regular (neatly arranged; 1 orientation); Seen in tough tissues: tendons, ligaments, aponeurosis irregular (fibers are haphazardly arranged); Seen in Periosteum,perichondrium

b. CT with specialized properties (diff types of fibers)(reticular fiber is collagen type 3, elastin fiber is collagen type 2)

i. Elastic - found in: wall of hollow visceral organs which are stratchable, wall of blood vessels, dermis of skin, lung parenchyma, trachea, bronchi, yellow (spine) and suspensory ligamentsSeen as black fibers (elastic fibers stained by Silver impregnation)(pink:collagen)

ii. Reticular (function to support) - fibers are thin and delicateArgyrophilic/Reticulin fibers - blackSilver impregnation - staining reticulin fibers to highlight the fibersSeen in liver spleen lymph nodes bone marrow (soft and mushy organs)Delicate fibers that insinuate individual cells (wrap them around)Delicate cytoskeletal frameworkSeen in hematopoeitic organs (liver spleen thymus bone marrow)Supports tissue until individual cellular levels

iii. Adipose - cells are made up of fat cells (adipocytes)Fat are filled w/ lipid in form of triglyceride and pushes the nucleus to periphery (signet ring appearance)Loose conective tissue mixes w fat

2. Embryonic CT (embryo/fetus)A. Mesenchymal - most primitive; scrutinized bec of its ability to contain a lot of stem cellsCells are completely undifferentiatedNothing specific at this point yetBackground : mixed soil (light violet color)Mesenchymal cell evolving toward mucous cell looks like spindling (umbilical cord)Mesenchymal cell is capable of differentiation of diff cell type (it can be any type of cell)

B. Mucous - seen in the Wharton's jelly of the umbilical cord (slimy/gelatin substance)distinctive cell of mucous connective tissue is the primitive fibroblast-spindle shaped or stellate-WHARTONS JELLY of the umbilical cord

3. Specialized CTA. CARTILAGEa. Hyaline Mixed soil appearance - bluish grayChondrocytes - rich in chondroitin-4-sulfateInactivated - chondrocytesActivated - chondroblastMost abundant cartilageLarynx, voicebox, tracheobronchial tree, ribs, costochondrial

b. FibrocartilageContain more collagen (abundant collagen)Like dense regularLinear formationFound in a very important organ that carries our weight (spine) each stack of spine contain fibrocartilage in between; intervertebral disk ; shock absorberc. ElasticWith chondrocytes but More elastin fibers; no blue gray color but more of pink; cells are bigger and closerLacuna - spacesChondrocytes are inside lacunaExternal ears, ext auditory canal, eustachian tube (connects middle ear to orasl cavity) , epiglottis, nose

B. BONEa. Spongyb. Compact

C. BLOOD AND LYMPH

Cellular components of CT:1. FibroblastPrincipal cells of the of the CRSynthesis of fibrous and amorphous ground substance GAG

Fibrocyte - inactiveGAG - ground substance

2. Macrophage (Histiocyte)- tissue phagocytes

Lungs- alveolar macrophages Skin - langerhans cells Bone - osteoclasts Liver - kuffner cells Brain - microglia Lymph nodes - satellite cells

3. Adult Fat cells (adipocytes)-heat production-storage of neutral fats-signet ring appearance (nucleus pushed into the periphery)

4. Plasma cellsInfrequentSeen in the areas of inflammationProduces antibodiesCartwheel or spoke wheel appearing Eccentrically located

D lymphocyte becomes plasma cell and produces antiboidues

Antibodies - produces antigens

5. Mast cells -With granules containing heparin, histamine and serotonin-Anaphylactic sensitivity reactions-Chemical mediators of inflammation-Contain Neurosecretory granules

Collagen fibers typeI - dermis, bone, tendon, fibrocartilageII - hyaline, elasticIII - endomysiumIV V

FAT types:Both come from Lipoblast1. Yellow/white/adult fat/unilocular fat (1 big fat globule)2. Brown fat/fetal fat/multilocular fat/hibernoma - fat used up by mammalian species thet hibernate in th winter-Has higher caloric value-foamy appearanceHibernoma - Tumor arising from brown fatAdults lose the brown fat

CYTOLOGYThe ultrastructure of the cellCells are the fundamental...Each cell has its own specializationNucelus separated w cytoplasm bec of nuclear membrane Plasmalemma - Edge of the cellCytoplasm - substance outside nuclear membrane (nucleoplasm - inside nuc memb)Nucleus - contains genetic materialImage - (Cross section of microvilli; circular - plasma membrane)Trilaminar - 3 layers A substance must pass this trilaminar layers before entering a cell

2 MODELSThe dark lines / circles are protein coats(2 protein coats) and in a middle is a lipid center (translucent area) - POLAR STRUCTURE AND A LIPID STRUCTURE

Polar head - dark (nitrogenous compound bridged to gylcerol)Non polar tail - translucent (complex of sat and non saturated fatty acids)The entire structure is a lipoprotein (protein portion - polar head)And is a phospolipid and is amphiphaticPolar head - water solubleLipid tail - non water soluble2. The fluid mosaic model-dynamic (constantly moving)- 3d representationIn between the two polar heads is a lipid (yellow) portionPhosphate - violet circlesThere are structures that pierces the entire distance of plasma membrane - Plasma proteins

Phagocytosis -cell eatingPinocytosis - cell drinkingExocytosis - release of productsEndoplasm - near the nucleus; sol phase (liquid phase; cellular components floating around)Exoplasm - far the nucleus; gel state(more rigid)Organelles - essential; part of microanatomy of cellENDOPLASMIC RETICULUM2 forms1. Rough er - has ribosomes; most typical; a tubule; network2. Smooth er - FUNCTIONS1. 2.

ER ends with golgi apparatus Golgi Apparatus - stack of platesConcavity - cave formation

Phases of concavity 1. Concave phase - trans (maturing) phase; faces the nucleus2. Cis phase - faces RER; connected to RERGOLGI APPARATUSFunctions of Golgi:-Meant to pack the product; concentate/modify the product-product to be excreted out by exocytosis

Sulfation - add a sulfateMucopolysaccharide -thick product; produced by goblet cell

MITOCHONDRIAcigar shapedPowerhouseSelf replicating organelle (capable of multiplying; has own DNA)

Crista - septationsAlong the wall of crista are globular units

Diff shape of crista depending on type of cell1. Closely packed crista - linear2. Vesicular - rounded; in myocytesKrebs citric acid cycle:This cycle generates the ATPFor every 1 cycle, it generates ATPAbnormall mitochondria (right): Muscle cells lack mitochondria; swelling of matrix; lack of atp production

LYSOSOMES-darkened/blackened rounded structures-Site where final product from golgi is stored (acid hydrolases)-Digests worn out products

Lypofucin granule - end product

2 sources of residual body1. Foreign material - bacteria (lysosome:heterophagosome)2. From cellular organelle itself(autophagosomes)

Autophagosome - important; protective mechanism; involved in apotosis (programmed cell death; destroys old cells)Functions of lysosome1. 2. CENTRIOLEor diplosomeCome in pairs during mitotic divisionSource of spindle tubule; produces spindle fiberSelf duplicating

X/S:3 filaments (microtubules)per group9 sets of triplets arranged in circular order; hollow cylinderIt will elongate during mitosisSite where chromosomes attach