Connective Tissue Flashcards
Embryonic CT
found in umbilical cord (Wharton’s Jelly) and pulp of developing teeth
rich in extracellular matrix, undifferentiated Mesenchymal (Stem) cells
not many collagen and reticular fibers
Mesenchymal (stem) cells
undifferentiated Mesenchymal cells differentiate into any blood or CT cell
Adult CT - Loose (areolar)
found in: mucosa and submucosa of various organs, surrounding blood vessels, nn and mm
deep to the epithelium of interstinal villi
contains: elastic and collagen fibers in ground substance, fibroblasts, Mast cells, Macrophages, and capillaries
Example - tunic aventitia
Adult CT - Dense Regular
found in: tendons, ligaments, cornea, and fascia
contains: regularly oriented parallel bundles of collagen fibers sperated by linear rows of fibrocytes
the nuclei of fibrocytes appear linear, cytoplasm hard to see
Adult CT - Irregular
Found in: dermis layer of skin and the submucosa of the gastrointestinal tract
Contains: coarse, thick, intertwined bundles of collagen fibers (arranged irregularly)
fibroblasts are sparse
Adult CT - Reticular (irregular)
characterized by abundance of reticular fibers (made by reticular cells/ fibroblasts)
Thin and branched
found in lymphatic tissue
Adult CT - Elastic (irregular)
characterized by abunance of elastic fibers
elastic fibers form discontinuous lamellae around the lumen, elastic fibers of blood vessels are made by sm. mm. cells
found in walls of large blood vessels and ligaments
White Adipose Tissue (special CT)
Acts as reserve of long term energy
made of unilocular adipocytes (have single large fat inclusion that push nucles to the side)
sometimes called signet rings
Brown Adipose Tissue (special CT)
serves to dissipate energy
made of multilocular adipocytes (mitochondria rich and have numberus lipid deposits
Fibroblasts
spindle shaped cell and an oval nucleus
cytoplasm does not show up well on light microscopy
synthesizse and secrete proseoglycans, glycoproteins, and the precursor molecules of collagen and elastin
lay down collagen fibers
make the elastic fibers, ground substance molecules
Collagen (fibroblasts)
three chain fibrous protein that form a triple-helix braided coiled-coil for tensile strength
Two types - Fibrillar, non fibrillar
Type I Collagen
fibrillar
Tissue: bone, tendon, dentin
Characteristics: banded fibers for tensile strength
Type II Collagen
fibrillar
Tissue: hyaline and elastic cartilage
Characteristics: thinner fibrils
Type III Collagen
fibrillar
Tissue: reticular lamina of basement membranes
Characteristics: reticular fibers
Type IV Collagen
non - fibrillar
Tissue: basal lamina
Characteristics: does not form bundles
