Connective Tissue Flashcards
What is the embryotic origin of CT?
Mesoderm
What intermediate filaments does CT have?
Vimentin
What is the most common cell in connective tissue proper?
Fibroblasts
What is the primary function of fibroblasts?
Production of all components of extracellular matrix fibers
What are the two types of histiocytes?
-Tissue Macrophage
-Dendritic cells
What is the function of a dendritic cell?
They present foreign molecules to t-lymphocytes
What is the fixed macrophage called in the brain?
microglial
What is the fixed macrophage called in the liver
kupffer cell
What is the fixed macrophage called in the lung
alveolar macrophages
What is the fixed macrophage called in the kidney
mesangial cell
What is the fixed macrophage called in the bone
osteoclasts
What are in mast cell cytoplasmic granules?
Histamine, heparin, proteases
How can you tell the difference between a macrophage and a plasma cell?
A plasma cell will have a dark, round, eccentric nucleus
What is the most abundant CT fiber?
Collagen
What is the strongest, most common type of collagen ?
Type I
What type of collagen is only found in cartilage?
Type II (hyaline)
What type of collagen supports organs?
Type III (reticular)
What type of collagen is in basement membranes?
Type IV
What type of collagen in non-fibrillar?
Type IV
How do you differenciate smooth muscle from dense regular type I CT?
smooth muscle will have more nuclei and more organized
What type of collagen does silver stain for?
reticular fibers of type III collagen
How are elastin organized into fibers?
Fibrillin is a protein that organizes elastin into fibers
What happens to elastin if no fibrillin is present?
elastin forms elastin sheets (lamellae)
What 3 stains can you use to identify elastic fibers?
-Verhoeffs-Van Gieson
-Orcein
-Resorcin-fuchsin
How can you distinguish between reticular fibers and elastic fibers?
The type of stain you use
What GAG does not have to bind to a protein core?
Hyaluronate
What is a proteoglycan?
GAG linked to a protein core
What is an important proteoglycan in cartilage? Why?
Aggrecan, resistant to compression
Why does loose CT not stain well and appear with alot of white space?
Because it contains few fibers but abundant ground substance which doesn’t stain well
What is CT ground substance?
an amorphis soup composed of GAGs, glycoproteins, and proteoglycans
