Connective Tissue Proper (draft)

Coordinator: Tomislav Jelesijevic

Mesenchymal stem cell function

Embryonic source of all connective tissue cells

Fibroblast function

Structural support. Synthesize collage, reticular and elastin fibers, extracellular substance (glycoproteins and glycosaminoglycans)

Pericytes function

Angiogenesis, maintenance of blood-brain barrier, vascular integrity, inflammation response

Adipocytes function

Energy storage, thermal insulation

Plasma cells function

Antibody production

Mast cells function

Important in allergies, mediate inflammatory response

Macrophages function

Immune mediated inflammatory response

Granulocytes function

Immune mediated inflammatory response

Lymphocytes function

Immune mediated inflammatory response

Mesenchymal cells

The stem cells of connective tissue hence have the potential to differentiate into nearly all connective tissue cells.

True or False: Mesenchymal cells are abundant in adult tissues.

False: rare in adult tissues, abundant in embryonic tissues

Which of the following in NOT a mixed/immobile CT cell?

Fibroblasts/cytes

Pericytes

Adipocytes

Granulocytes

Mast cells

Undifferentiated mesenchymal cells

Granulocytes are transient/mobile CT cells along with lymphocytes, monocytes, and plasma cells.

What is depicted in the photo?

Mesenchymal stem cells in between process of differentiating.

What is depicted in the photo?

Fibrocytes (darker, more condensed) and fibroblasts (lighter)

What is depicted in the photo?

Macrophages

What is depicted in the photo?

Mastocytes

What is depicted in the photo?

Pericytes

What are the most important, abundant, long-living connective tissue cells?

fibroblast/cytes

What do fibroblast/cytes make?

Connective tissue fibers (collagen, reticular and elastic fibers) and ground substance

Difference between a fibroblast and fibrocyte?

smaller/larger nuclei and active/inactive cell

What identifies a pericyte?

associated with capillaries and endothelial cells

What are the two most common forms of adipocytes?

Unilocular and multilocular

Unilocular adipocytes

White fats cells (loose)

Single large fat lipid droplet like cytoplasm

Unilocular/White adipocytes function

Energy storage, insulation, protecting vital organs, secretion of adipokines

Multilocular

Brown fat cells (dense) in small mammals and newborns.

Multiple small fat lipid droplets in cytoplasm and high number of mitochondria.

Main functions of multilocular/brown adipocytes

thermogenisis and energy storage

What is the name for an inactive fibroblast?

Fibrocyte

What type of collagen is in white adipocytes?

type IV

What is special about white adipocytes outer layer?

Lipid droplets covered with phospholipid monolayer

Why are macrophages called glitter cells?

foamy cytoplasm

What are macrophages derived from?

Monocytes in the blood

Another name for macrophages

Histiocytes

Examples of macrophages

Kupffer cells in liver and microglial cells in the brain

Perivascular

Usually found around blood vessels

Metachromatic

stain a different color than dye used

Where are mastocytes usually found?

Found around blood vessels (perivascular)

What granules are metachromatic?

Mastocyte granules

What cells are transient/mobile?

leukocytes: ben, monocytes, lymphocytes

Plasma cells

activated B lymphocytes that secrete a large number of antibodies

What is the ground substance made of?

Glycosaminoglycans

What type of collagen do reticular fibers have?

type III

How many types are collagen fibers are there?

28

What cells/fibers are basophilic and which is acidophilic?

Mast cells and collagen fibers