MCM 2-28 Microanatomy of Connective Tissue Flashcards
(50 cards)
definition of connective tissue
functions?
examples?
tissue that forms a continuum with the other 3 major tissues to maintain a functionally integrated body
mostly structural. characterized on basis of its ECM
organ capsules, tendons/ligaments, areolar tissue filling spaces, fat, cartilage, bone.
connective tissue develops from
embyronic mesenchyme, which forms from embryonic neural crest
embyronic neural crest -> embryonic mesenchyme -> connect tissue
describe mesenchymal appearance
what can they function as in adult tissue?
oval nucleus, prominent nucleoli, small amount of cytoplasm
stem cells
if a cell has lots of euchromatin
it is replicatively/synthetically active
connective tissue has two components
ECM - ground substance, protein fibers, tissue fluid (blood/plasma)
and connective tissue cells (resident and immigrant) CT cells
resident CT cells
arise in CT, spend entire life there
create the fibers and ground substance of CT, along with adipocytes
mesenchymal cells, fibroblasts, fibrocytes, reticular cells, adipocytes
immigrant CT cells
arise in hematopoetic bone marrow stem cells, migrate into the CT
macrophages, mast cells, plasma cells, leukocytes, eosiniphils (lots of cells from bone marrow)
-cyte?
blast?
cyte is a more mature form
blast is a cell that prolfierates and gives rise to other cells
fibroblast appearance
euchromatic nucleus, lightly stained
lots of organelles in cytoplasm
fibrocyte role and appearance
focused on secretion of collagen and ground substance. no longer proliferating
nucleus is more condensed heterochromatin, not the active euchromatin-like fibroblast.
blasts vs cytes
blasts - highly euchromatic nucelus, packed with organelles (golgi, ER) and irregular shaped
cytes - spindle shaped, heterchromatic necleus, fewer organelles, embedded within matrix.
reticular cell role and appearance
fibroblast like cells that produce reticular fibers in hematopoietic, lymphoid, and adipose tissue
stellate shaped cells with oval euchromatic nucleus that has prominent nucleolus
adipocytes
single lipid dropet that pushes cytoplasm and nucleus to the periohery (signet ring cell).
brown (multilobular) and white (unilobular)
describe macrophages
apperance?
how do we ussualy idenfity?
monocytes travel in blood and migrate into CT to form macrophages
smaller than fibroblast, heterochromatic KIDNEY SHAPED nucleus and cytoplasm filled with granules. Dark heterochromatin ring around periphery. lots of lysosomal vacoules
idenfity in animals by injecting trypan blue (colloid dye)
Mast cells
largest of CT cells
cytoplasm filled with membrane-bounded basophilic granules that contain heparin, chondriton sulfate, and ECF-A
allergic reactions, found around blood vessels
light colored cytoplasm with darker central nuclues
plasma cells
differentiate from antigen stimulated B-cell
large, ovoid cells
eccentric nucleus, abundant RER, “CLOCK FACE” nucleus, clear zone near nucleus contains golig and centrioles
ground substance description
consists of?
functions as?
viscous mixture that binds cells to CT fibers
consists of GAGS, proteoglycans, and multiadhesive glycoproteins (lamin and fibronectin)
functions are both structural and physiological - homrones and growth factors have resovoirs in GS
CT fiber types
collagen - >50nm fibrils, 1-20 micron fibers. Thickest
Reticular fibers -
describe collagen type 1 (exam q)
forms triple helix, when bind to one another, form 64 periodicity. striped. form tendon
most widespread, most abundant protein in the body (90%). resists tension like in tendons
collagen 3
forms reticular fibers, flexible meshwork
collagen 2
cartilage, resists pressure
collagen 4
important component of basal lamina
collagen 7
anchores basement membrane to collagen fibers
basal lamina vs basement membranes
BL - lamina lucida and lamina densa
bm = basal lamina + reticular fibers
