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49 Cards in this Set
- Front
- Back
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what is connective tissue
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relatively few cells in an ECM formed of fluid, ground substance, and various fibers
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what is mesenchyme?
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pluripotent precursor to adult CT
derived mainly from mesoderm, but some from neural crest tissue consists of stellate pluripotent cells, reticular fibers, and ground substance |
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what is mucous connective tissue
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found only in umbilical cord and parts of embryo
Wharton's Jelly few fibers (collagen Type I and III) in soft jelly-like mtx large stellate fibroblasts |
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what are some specialized forms of CT?
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adipose, blood, bone, cartilage, hematopoietic, lymphatic
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what are the functions of CT?
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structural support
medium for exchange defense/protection storage of energy store potential energy thermal regulation controlled motion |
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what are the components of ECM?
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fibers
ground substance |
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what is collagen?"
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most common fibrous material
high tensile strength 25 known types |
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what is collagen fibers made of?
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tropocollagen is basic molecule w/ 3 alpha chains in a helix
fibrils are aggregates of tropocollagen linked head to tail, side by side fibrils form fibers which form bundles |
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what is tropocollagen?
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basic collagen molecule of 3 alpha chains in a helix
gly-x-y where x and y are usu proline, hydroxyproline, and hydroxylysine |
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what is Type I collagen?
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major
in dermis, ligament, tendon, organ capsules, bone, cornea, and teeth 30% of protein in body produced by fibroblasts ACIDOPHILIC; and blue/green on trichrome or Azan stains Striated fibrils ->form fibers |
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what is Type II collagen?
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in hyaline and elastic cartilage and in vitreous body of eye
produced by chondrocytes when in cartilage usu thin fibrils, not fibers |
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what is Type III collagen?
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reticular fibers
fibrils from thin fibers in delicate network PAS positive agyrophilic (stains w/ silver) produced by fibroblasts in loose CT in stroma of certain glands, lymph nodes, spleen, liver, lung |
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what is Type IV collagen?
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make up lamina densa of basal lamina
FORMS A MAT, not fibers propeptides not removed from procollagen..cannot make fibrils |
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what is Type VII collagen?
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in lamina reticularis
forms anchoring fibrils, which are bound to lamina densa and type I and III collage fibrils in CT |
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what are elastic fibers?
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for recoil
core of elastin surrounded by microfibrils of glycoprotein fibrillin in loose CT: long, slender, with branching networks in elastic ligaments: coarse bundles in tunica media of large arteries: fenestrated sheets |
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how do you stain elastic fibers?
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unstained: look glassy if thick
special stains: resorcin-fuchsin, aldehyde-fuchsin, and Verhoeff's picro-ponceau color elastin |
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what is ground substance made up of?
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hydrated mix of GAGs, proteoglycans, and glycoproteins
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what are glucosaminoglycans?
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long,unbranched polysaccharides w/ disacc repeat unit
<300 repeats (except for hyaluronic acid) |
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what are proteoglycans?
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GAGs (except hyaluronic acid) covalently bound to core protein
form test tube brush HIGHLY BASOPHILIC b/c neg carboxyl and sulfate grps |
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what do proteoglycans do?
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filters of macromolecules
attracts water...gel-like bind to collagen and cross linke components of ECM bind to signaling molecules and control their fxn sometimes anchors cell to mtx |
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what is a proteoglycan aggregate?
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when proteoglycans attach to hyaluronic acid
found in cartilage link proteins reinforce noncovalent attachment of proteoglycans to hyal acid form gel of ground substance |
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what are adhesive glycoproteins?
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glycoproteins in ground substand that bind to cell mbns and/or ECM
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the binding domains of adhesive glycoproteins can bind to?
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integrins (transmbn proteins linked to cytoskel; like cell to mtx)
collagen fibers proteoglycans |
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what are some glycoproteins with cell adhesion properties?
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fibronectin
plasma fibronectin laminin (only in lamna lucida of basal lamina) chondronectin osteonectin |
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what are the two types of cells in CT?
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fixed
transient |
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what are the fixed cells of the CT?
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fibroblasts
adipose cells myofibroblasts macrophages mast cells |
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what are the transient cells of the CT?
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plasma cells
leukocytes macrophages |
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what do fibroblasts do?
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synthesize almost all components of ECM
active fibroblasts - spindle shaped, slightly basophilic cyto, ovoid nucleus inactive fibroblasts - less RER, less basophilic, pink cyto |
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where are adipose cells found?
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in loose CT
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what is white adipose tissue?
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unilocular adipocytes
signet ring cyto and nuclei pushed to side |
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what is brown fat?
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multilocular adipocytes
organized into lobules, looks glandular more vascular than white fat; blood + cytochromes in mit give brown color in fetus and young children: neck, interscapular region, next to major bl vessels abundance of mit..generate HEAT |
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what are myofibroblasts?
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look like fibroblasts on LM
have RER and golgi, and lack basal lamina (like fib) but have bundles of actin filaments and dense bodies (like smooth musc cells) |
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what are macrophages and what do they do?
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derived from monocytes
large, irregularly shaped phagocytize and do intracell breakdown also immune response, produce cytokines, phago old RBCs, help develop RBCs, produce enz to turn over ECM |
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what are types of phagocytic cells found in the body?
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histiocytes - in loose CT
Kupffer cells - liver Dust cells/alveolar macrophage - lung Osteoclasts - bone Langerhands cells - epidermis Microglia - brain |
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what are mast cells?
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have secretory granules of histamine and heparin for inflammatory response
1st exposure to antigen: IgE isbound to receptors on mast cell plasmalemma 2nd exposure: mast cell granule content released, and synth/release leukotrienes |
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what do mast cells look like?
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have granules that can be seen with special stain (i.e. toluidine blue -> metachromasia)
resemble basophils and secrete similar products |
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what are some reactions mediated by mast cells?
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hay fever
asthma anaphylaxis |
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what are plasma cells?
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large ovoid cells derived from B lymphocytes
manufacture antibodies |
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what do plasma cells look like?
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basophilic cytoplasm w/ pale area near eccentric nucleus
cart wheel nucleus basophilia = RER; pale = golgi |
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what are leukocytes?
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pass through capillary walls by migrating b/w endothelial cells (diapedesis) into CT
neutrophils, eosinophils, basophils, lymphocytes,and monocytes |
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what is loose CT?
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abundant ground substance, few fibers, scattered cells
papillary layer of dermis, superficial fascia, mesothelial cells, in mucous mbns, and surrounding blood vessels and periph nerves |
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what is lamina propria?
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loose CT just deep to epith and basement mbn(e.g. intestine, trachea)
more cellular |
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what is dense irregular CT?
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many collagen bundles in irregular direction
less ground substance and less cells than loose CT in reticular layer of dermis, capsules of organs, and sheaths of tendons and nerves |
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what is dense regular CT?
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parallel bundles of collagen fibers; tendons, ligaments, aponeuroses, and stroma of cornea
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what is dense regular elastic tissue?
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little collagen, lots of elastin in bundles
in ligamenta flava, ligaments, fenestrated sheets in tunica media of large arteries |
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how is inflammation classified?
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dolor - pain
calor - heat rubor - color tumor - swelling |
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what is scurvy?
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vit C deficiency
vit C needed to convert proline to hydroxyproline, which is essential in collagen poor wound healing, tooth loss |
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what is ehlers-danlos syndrome?
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heritable mutation in lysyl hydroxylase, causing abnormal tropocollagen crosslinks
joint laxity, skin extensibility, tissue fragility |
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what is Marfan's Syndrome?
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Mutation in fibrillin gene, causing abnormal elastic fibers
tall flexible...large heart.. Abe lincoln |
