Cells of Connective Tissue Flashcards
what are the cells of connective tissue derived from
mesenchyme
what are the fixed cells?
fibroblasts, myofibroblasts, adipose tissue, mast cell, macrohage
what are the transient cells
plasma cells, lymphocytes, neutrophils, eosinophils, basophils, monocytes, macrophages
Fibroblasts
most abundant cell in connective tissue, these cells synthesise ECM. there are two parts: active and inactive fibroblasts
Active: are elongated fusiform cells and have ovoid nuclei with granules. they are specialised for tissue repair with contractile ability
Inactive: smaller and more ovoid nucleus. have an acidophilic cytoplasm. secretes ECM
adipocytes
these store and metabolise fat. two types: uni and multiocular
uniocular: are white, and are large circular cells with a large lipid droplet. it pushes cytoplasm to the edge of the cell.
multiocular: are brown and less abundant. have several small droplets
Macrophages
can be both fixed and transient. are subdivided into phagocytes and antigen presenting cells. their morphology = large and irregularly shaped, have an ovoid indented nucleus and lysosomes which appear as small dense granules (basophilic)
Mast cell
are one of the largest fixed cells. central nucleus (ovoid) and have granules. have histamine and heparin in granules, and cytokines for initiation of immune response.
what do mast cells do upon first exposure and subsequent exposures
first exposure: igE antibody formation which bind to Fc receptors on mast cell
subsequent exposures: antigen binds to IgE, which causes a release of primary mediators from granules which initiates an inflammatory response
plasma cells
transient cell. found in places of chronic inflammation o where pathogens have entered tissues. they are part of the adaptive immune system and are derived fom B lymphocytes. produce antibodies for specific antigens
