4. Connective Tissue Cells: General & Fibroblasts
resident cells
(fixed) undergo mitosis and spend most of life in CT
four types of fibroblasts
active, inactive, myofibroblasts, mesenchymal cells
fibroblast location
close to collagen fibers
myofibroblast smooth muscle similarities
contain bundles of actin filaments and dense bodies (but no external lamina)
inactive fibroblast nucleus
dark, elongated, heterochromatic
inactive fibroblast presence
dense, not growing, connective tissue
fibroblast appearance
diff in diff tissue types
mesenchymal cells presence
embryonic connective tissue
myofibroblast properties
fibroblasts and smooth muscle
types of resident cells
fibroblasts, adipocytes, macrophages, mast cells
inactive fibroblasts
fibrocytes
inactive fibroblast structure
limited cytoplasm, less well-developed Golgi and RER
active fibroblasts presence
loose connective tissue, actively growing tissue, wound repair
active fibroblast nucleus
pale, oval, euchromatic with one or more nucleoli
mesenchymal cells unique feature
pluripotent, give rise to other connective tissue cells
fibroblast cell
principal resident cell of CT
fibroblast function
producing ECM components (collagen & elastic fibers, GAGs, proteoglycans, multiadhesive glcoproteins)
mesenchymal cells appearance
resembles active fibroblast (pale, euchromatic nuclei, well-developed RER and Golgi)
two types of connective tissue cells
resident and transient
active fibroblast structure
thin processes, abundant cytoplasm, RER and Golgi
myofibroblast presence/use
wound sites, wound closure
