Term
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Definition
| complex of cells and extracellular materials that provides the supporting and connecting framework for all the other tissues of the body |
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Term
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Definition
| embryonic tissue from which most connective tissues develops from |
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Term
| Types of connective tissue |
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Definition
1. embryonic mesenchyme
2. connective tissue proper; forms tendons, ligaments, and organ capsules
3. adipose tissue
4. cartilage
5. bone
6. blood and bone marrow |
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Term
| Connective tissue characteristics |
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Definition
1. acellular
2. main constituent is extracellular matrix |
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Term
| Components of extracellular matrix |
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Definition
1. ground substance (proteoglycans, glycoproteins)
2. fibers (collagen, reticular, elastic)
3. tissue fluid (derived from blood) |
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Term
| Types of connective tissue cells |
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Definition
1. fibroblasts
2. adipocytes
3. chondrocytes
4. osteocytes
*secrete the ground substance and fiber components of the matrix and are embedded in it |
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Term
| Principle cels of the CT proper |
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Definition
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Term
| Resident population of cells in CT proper |
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Definition
1. fibroblasts (elongated cells)
2. macrophages
3. mast cells |
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Term
| Wandering cell population of CT proper |
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Definition
1. plasma cells
2. other WBC's |
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Term
| components of ground substance |
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Definition
1. physical properties of a viscous solution or a thin gel which the cellular elements and fibers are embedded.
2. water, proteoglycans, glycoproteins |
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Term
| Function of ground substance |
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Definition
| acts as lubricant and barrier for the penetration of particles such as bacteria |
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Term
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Definition
| 1. consist of a protein core with many covalently attached glycosaminoglycan (GAG's) radiating in a brush configuration |
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Term
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Definition
| linear polysaccharides formed by repeating disaccharide units |
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Term
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Definition
| linear polysaccharides formed by repeating disaccharide units |
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Term
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Definition
1. hyaluronic acid
2. chondroitin sulfate
3. dermatan sulfate
4. heparan sulfate
5. keratan sulfate
*All except hyaluronic acid are covalently attached to protein core |
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Term
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Definition
1. GAG that is not covalently bound to protein core.
2. present in loose connective tissue including synovial fluid, vitreous humor of eye, cartilage, blood vessels, skin, umbilical cord
3. retards water movement, provides cushioning
4. in cartilage, can form huge aggregates |
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Term
| Properties of proteoglycans |
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Definition
1. extremely hydrophilic: bind to water,sodium, cartilage and allow for transport of electrolytes, cushion compressive force, and limit bacteria spread
2. synthesized by fibroblasts
3. turn over rapidly |
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Term
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Definition
1. consist of protein core to which carbs are attached.
2. responsible for linking components of the matrix to each other and to cells. |
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Term
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Definition
1. fibronectin
2. laminin
3. integrins |
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Term
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Definition
1. synthesized by fibroblasts and some epithelia
2. binds collagen and proteoglycans
3. form integrated fibrillary network in ECM
5. also found in lamina densa |
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Term
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Definition
| constituent of lamina densa that binds to proteoglycans, type IV collagen and cell surface receptors |
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Term
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Definition
transmembrane proteins that allow cells to bind with colagen, fibronectin, and laminin with low affinity.
2. bind to actin filaments or intermediate filaments so that cytoskeleton effectively linked to ground substance, allowing polarity |
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Term
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Definition
1) collagen (thick)
2) reticular (actually type III collagen)
3) elastic (thick) |
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Term
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Definition
| protein that forms extracellular fibers and basement membranes throughout the body |
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Term
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Definition
Each molecule is composed of:
-3 alpha peptide chains; two alpha1 chains, one alpha2 chain
-held together by hydrogen bonds and hydrophobic interactions
-intertwined to form a helix |
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Term
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Definition
-flexible, great tensile strength
-bone, tendon, organ capsules, dermis, tooth dentin
-also known as tropocollagen |
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Term
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Definition
-form delicate meshworks to support cells of lymphoid and glandular organs
-main component of reticular fibers
-usually co-localized with Type I |
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Term
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Definition
-part of structural network of basal lamina
-does not form fibrils or fibers |
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Term
| Collagen biosynthesis cells |
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Definition
| fibroblasts, osteoblasts, chondroblasts, epithelial cells, schwann cells |
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Term
| Steps of collagen biosynthesis |
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Definition
1. alpha chains synthesized on polyibosomes on RER (preprocollagen with signal peptide allows simultaneous insertion in cisternae. Registration peptides ensure correct formation of fibrils).
2. Cleavage of signal peptide forming procollagen; hydroxylation of proline and lysine residues (Vitamin C dependent); glycosylation; tripical helical structure.
3. packaging into vesicles in Golgi; secreted
4. Cleavage of registration peptides by procollagen peptidases forming tropocollagen. Assemble into collagen fibrils. Type I and III fibrils assemble to form fibers. |
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Term
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Definition
| distinct crossbanding of collagen fibers under polarizing microscope |
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Term
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Definition
| parallel array construction of collagen fibers |
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Term
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Definition
-genetic defect in synthesis of procollagen and tropocollagen
-hypeextensible skin, hypermobile joints, hernias, poor wound healing, skeletal deformities |
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Term
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Definition
-genetic defect in type I collagen formation
-multiple bone fractures and deformities, blue sclerae, thin skin |
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Term
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Definition
caused by lack of vitamin C
collagen fibers not formed because VC is required co-factor for hydroxylation of procollagen lysine and proline residues |
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Term
| progressive systemic sclerosis |
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Definition
1. error in degradation of collagen (collagenases)
2. may be autoimmune disease
3. collagen accumulates in skin and internal organs due to inadequate degradation and increased collagen synthesis |
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Term
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Definition
-type II collagen fibrils
-thin fibers (20-30 nm)
-form delicate meshwork around cells
-allow for change in volume or form
-can be stained with silver
-present in BM |
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Term
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Definition
| silver-loving (reticular fibers) |
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Term
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Definition
-easily stretch and return to normal
-mostly abundant in respiratory system, elastic ligaments
-large vessels contain sheets (lamellae) |
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Term
| elastic fiber composition |
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Definition
-thin bundles of microfibrils (10-12 nm) called fibrillin
-encases by protein elastin |
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Term
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Definition
-concentric layers presented in blood vessels
-fenestrated sheets of elastin
-no fibrillin |
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Term
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Definition
-produced by fibroblasts and smooth muscle cells
-secreted as proelastin and polymerizes
-hydrophobic
-have desmosine and isodesmosine for binding |
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Term
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Definition
-genetic disorder
-absence of fibrillin microfibrils
-elastic lamellae of aorta not attached to smooth muscle
-degeneration and aortic aneurism |
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Term
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Definition
-derived from capillaries within CT
-contains ions and low molecular wt proteins |
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Term
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Definition
| -occurs when amt of tissue fluid in CT increases, no equilibrium between hydrostatic and osmotic pressure within capillaries and venules |
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Term
| Categories of connective tissue proper |
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Definition
1. dense CT
irregular and regular
2. loose (areolar) CT |
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Term
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Definition
-collagen fibers not preferentially oriented
-form 3-D network resistent to stress
-found in dermis of skin |
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Term
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Definition
-collagen arranged in rows of fibroblasts between collagen bundles
-found in tendons, ligaments, cornea
-resistance to traction forces |
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Term
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Definition
-ground substance predominates
-most abundant CT in body
-supports epithelial tissue, ensheaths blood vessels, nerves, and muscles, established fascial planes |
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Term
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Definition
1. fibroblasts
2. macrophages
3. mast cells |
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Term
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Definition
1. plasma cells
2. lymphocytes
3. neutrophils
4. eosinophils
3. basophils |
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Term
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Definition
-synthesize and secrete ECM
-may differentiate into myofibroblasts |
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Term
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Definition
-long living phagocytes
-defense activity
-cleanup activity
-present antigens to lymphocytes for immune response |
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Term
| mononuclear phagocyte system |
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Definition
-phagocytic cells derived from bone marrow
-10-30um with folds and projections
-big golgi, RER, smooth ER
-lots of mitochondria, secretory vesicles, vacuoles and lysosomes |
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Term
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Definition
| fusion of many macrophages with up to 100 nuclei |
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Term
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Definition
-20-30um, oval shaped
-granules contain histamine, heparin, ECF
-bind Ige (produced by plasma cells)
-numerous on skin and organ capsules |
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Term
| immediate hypersensitivity reaction |
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Definition
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Term
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Definition
| produce slow contractions of smooth muscle |
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Term
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Definition
| causes smooth muscle contraction, increases capillary dilation and permeability |
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Term
| eosinophil (and neutrophil) chemotactic factor |
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Definition
| attract eosinophils and neutrophils to site |
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Term
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Definition
-derivative of B lymphocytes
-secrete antibodies
-rarely seen in CT |
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Term
| other white blood cells in CT |
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Definition
| monocytes, neutrophils, eosinophils, basophils, lymphocytes |
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Term
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Definition
1. support (epithelia, muscle, nervous)
2. defense (inflammatory cells, gel makes movement of bacteria hard)
3. repair-granulation and scar tissue formed by fibroblasts (inhibited by cortisol)
4. transport (closely associated with blood and lymph capillaries)
5. storage (fat, water, electrolytes) |
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Term
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Definition
-specialized type of CT for storage of triglycerides
-shock absorbers
-limitation of movement |
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Term
| adipose tissue characteristics |
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Definition
-very vascular
-adipocytes secrete and surrounded by external lamina and collagen (reticular) fibers |
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Term
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Definition
1. unilocular
2. multilocular |
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Term
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Definition
-characteristic of white adipose tissue
-single inclusion of lipid
-large (50-150um)
-primary storage compartment of mammals |
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Term
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Definition
free fatty acid + glycerol=trigylceride
-insulin inhibits lipases and increases glucose uptake & glycolysis |
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Term
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Definition
lipolysis
-via ACTH, epinephrine, glucagon
-source of ATP |
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Term
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Definition
-decrease appetite
-increase metabolic rate
-increase gonadotrophin production |
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Term
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Definition
| increases insulin sensitivity--burn glucose |
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Term
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Definition
-decreased sensitivity to insulin
-insulin resistance (Type II diabetes) |
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Term
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Definition
-increase in leptin
-decrease in adiponectin
-increase in resistin |
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Term
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Definition
-coordinates metabolism (leptin, etc)
-when to reproduce
-constriction of blood vessels
-increase immune response (cytokines) |
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Term
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Definition
-brown adipose tissue in infants
-heat production organ
-brown from mitochondria
-has uncoupling protein (UCP-1): allows uncoupling of oxidation of fatty acids and ATP production
-stimulated by norepinephrine
-FFA's not released intro bloodstream |
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