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33 Cards in this Set
- Front
- Back
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What are the 3 types of connective tissue?
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1. Loose/ areolar fibrous
2. loose/areolar cellular 3. dense irregular 4. dense regular |
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What is connective tissue made of?
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1. cells
2. fiber 3. ground substance |
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What fibers can compose the connective tissue matrix?
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reticular fibers, elastic fibers, collagen
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What type of collagen is reticular fibers?
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III
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What is defined as embryonic connective tissue?
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mesenchyme
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Where is mesenchyme found?
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umbilical cord (wharton's jelly) embryonic heart valves (cardiac jelly) pulp of developing tooth
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What cell types are in mesenchyme?
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mesenchymal cells- resemble fibroblasts but are more angular shaped
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What stain should be used to study reticular fibers?
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argyrophilic silver salts
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What fiber do muscles synthesize?
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elastic fibers
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What are the special types of connective tissue?
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1. adipose
2. bone 3. hematopoietic tissues |
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What is the major component of ground substance?
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proteoglycans
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Describe proteoglycans, their structure and role in connective tissue ground substance.
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They suck up water.
They the proteoglycans form aggregates: The core proteoglycan is attached to a linker protein which attaches to a hyaluronan backbone |
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What composes Hyaluronan?
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non-sulfated glycosaminoglycans: ~2500 repeating dissaccharide units of N-acetylglycosamine and D-glucuronic acid
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Why do proteoglycans become so hydrated?
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because of the richness of -OH, carboxyl and sulfate groups
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How can bacteria effect connective tissue?
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Produce enzyme hyaluronidase that breaks down the proteoglycan aggregates
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What are the fixed cells of the connective tissue?
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1. fibroblasts
2. mast cells 3. reticular cells 4. pericyes 5. adipocytes 6. undifferentiated mesenchymal cells |
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What is the dominate glycosaminoglycans in the following tissues: skin, cartilate, bone
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skin: dermatan sulfate
cartilage: chondroitin 6- sulfate and keratan sulfate bone: chondroitin 4-sulfate |
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Describe the synthesis of collagen.
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1. Fibroblasts (or osteoblast, chondroblast, odontoblast) synthesis precollagen and procollagen and hydroxylation of lysine and proline, glycosylation and disulfide bond formation in RER
2. golgi packages and secretes procollagen 3. remove non helical domain of procollagen to form tropocollagen 4. tropocollagen forms collagen fibril 5. cross-linking of collagen fibrils to form fibers |
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What is FACIT?
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fibril associated collagens with interrupted triple helices= a type of collagen that is also a proteoglycan
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What is Ehlers- Danlos syndrome?
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Defect in procollagen peptidase molecule so tropocollagen can not be formed
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What synthesizes and secretes elastic fibers?
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fibroblasts
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How are elastic fibers synthesized?
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1. fibroblast RER synthesizes fibrilllin 1, fibrilin 2, proelastin (desmosine + isodesmosine) and mricofibril-associated
glycoprotein (MAGP) 2. In extra cellular space: MAGP + tropocollagen + fibrillin I and II = immature elastic fiber |
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What 2 unique AAs make up proelastin?
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desmosine and isodesmosine
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What are the roles of fibrillin I and II in elastic fibers?
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1= structural support
2= regulates assembly of elastic fibers |
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What is Marfan syndrome?
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deficiency in fibrillin I: patients are tall with long arms and legs and fingers and toes
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What are the mobile cells of the connective tissue?
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1. neutrophils
2. basophils 3. macrophages 4. eosinophil 6. lymphocytes |
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What do plasma cells and lymphocytes produce?
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antibodies
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What is the structure and function of macrophages?
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they are vacuolated cells with lysosomes. The nucleus looks irregularly indented and it presents antigens to lymphocytes by eating an antigen and presenting it on the surface
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What is the difference between monocytes and macrophages?
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The same cells but named differently depending on location. Monocytes are in the blood and macrophages are in the tissue
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What is the structure and function of mast cells in CT?
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Arise from basophils in the pbl stream and have lots of granules that release histamine (causes vasodilation) too much can cause anaphylactic shock
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What is the connection between plasma cells and B cells?
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plasma cells are activated B cells that have a clock -face pattern of heterochromatin in the nuclease
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What is brown fat?
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present in infants and its adipocytes rich in mitochondria surrounded by pbl vessels. It is inefficient because it releases heat instead of storing fat
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Describe adipogenesis.
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mesenchymal cells give rise to preadipocytes which form brown fat in infants and white adipocytes in adults. The IGF-1 receptor stimulates both pathways
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