Connective Tissue Flashcards
What makes up the ECM (matrix)
Ground substance
Fibers
The most common type of fiber is…
Collagen
The ground substance is made up of ____ and _____
GAGs and PGs
The more sulfates GAGs in the ground substance, the more _____ the tissue
Rigid/robust
What is the diffusion medium of CT?
Ground substance
Besides collagen, what fibers are in the matrix?
Elastin
Amorphous proteoglycans are good at binding _____, especially the sulfated GAGs they exhibit
Water
Collagen types: most common. Present in bone, L-CT, D-CT, Dermis, tendons, capsules of organs
Type 1
Collagen types: collagen of cartilage
Type 2
Collagen types: aka reticular fibers, in dermis, in reticular lamina
Type 3
Collagen types: basal laminar collagen, non-fibrous
Type 4
What is the most abundant protein - 30% of dry body weight?
Collagen
Collagen is mostly secreted by:
Fibroblasts
What type(s) of collagen are fibrillar (make fibers)
Type 1,2,3
What type of collagen forms the basal lamina of the basement membrane
Type 4
Collagen synthesis begins at the _____ where various amino acids (typically lysine and _____) are linked together in a single stranded peptide called _______
rER
Proline
Procollagen alpha chains
In the _____, procollagen alpha chains assemble in a triple helix structure which is then called a _________
rER
Procollagen molecule
Procollagen molecules are soluble and can be stored in ______ until release
Fibroblasts
Procollagen molecules are transferred into the _____ via ______
Golgi apparatus
Transfer vesicles
In the golgi, the Procollagen molecule receives the finishing touches on its inactivation peptides. These peptides will keep the Procollagen molecules from undergoing _______ until they have been secreted
Fibrillogenesis
Procollagen peptidase cleave off the terminal peptides, transforming Procollagen into insoluble collagen molecules, which aggregate to form collagen ______
Fibrils
Procollagen w/o activation peptides
Tropocollagen
Fibrillogenesis: creating fibrils
Fibril—> ______ —> _____
E.g. (many fibrils make a _____ , many of those make a _____)
Fiber
Bundle
What forms covalent bonds between tropocollagen molecules to reinforce the fibril?
Lysyl oxidase
These fibers have a fine branching pattern —> framework (not as bundles), act as supportive stroma
Collagen type 3
Collagen type 3 is found in… (8 places)
Lymphoid organs
Endocrine glands
Liver
In basement membrane
Surrounding adipocytes
Small blood vessels
Nerves
Muscle cells
These fibers are secreted by fibroblasts and smooth muscle cells. They are made of elastin and fibrillin
Elastic fibers
What forms a scaffold? Elastin binds to this scaffold to make the fiber
Fibrillin
Marfan’s syndrome is a mutation in …
Fibrillin gene
Aortic swellings (aneurysms), curved spine, excessively long limbs, crowded teeth are symptoms of what?
Marfan’s syndrome
What kind of cells have a spindle shaped nucleus?
Fibroblasts
What is the most common cell in CT?
Fibroblasts
Fibroblasts with more rER and golgi have what kind of nucleus?
Leptochromatic
Fibrocytes are ______ fibroblasts. This leads them to have a ________ nucleus.
Inactive
Pachychromatic
What do fibroblasts do?
Secrete collagen, elastin, GAGs, PGs, ground substance
Scar tissue that grows beyond the boundaries of the original wound and does not regress is called?
Keloid
This type of cell is oval shaped and appears very granular because of the large amounts of secretory vesicles
Mast cells
Where are mast cells found?
Loose CT near smaller blood vessels, skin, mucosal membranes of GI and respiratory tracts
Mast cells originate in _______
Bone marrow
What do mast cells do?
Secrete heparin, histamine, serine proteases, cytokines, leukocyte chemotaxi factors
Mast cells secrete heparin, histamine, serine proteases, cytokines, leukocyte chemotaxi factors, etc. What is this important for?
Generating an inflammatory response
What kind of cells are irregularly shaped with a large leptochromatic nucleus?
Macrophages
What is the function of macrophages?
Remove debris at the site of inflammation or injury
Where are macrophages found?
CT - lungs, bone marrow, precursors of macrophages called monocytes are found in blood
What type of cells are ovoid shaped with a pachycromatic nucleus?
Plasma cells
Plasma cells are found where?
CT - originating with other blood cells in the bone marrow, blood
What is the function of plasma cells?
Production of immunoglobulin antibodies. The function of the antibody is to neutralize the antigen it binds to
What kind of CT is found under epithelia all throughout the body and a filler between muscle fibers/nerves?
Loose CT
Loose CT has _____ GS and ______ fibers
More
Less
What kind of CT is predominantly made up of T1 collagen?
Dense CT
Dense CT has _____ GS and _____ fibers
Less
More
Dense connective tissue function
Protects organs
Dominant cell type in dense CT
Fibroblasts
Mucoid CT is also known as …
Wharton’s Jelly
Where is mucoid CT found?
Umbilical cord
Embryonic CT has _____ fibers, _____ cells, ______ GS
Less
More
More
What is regenerative tissue of the growing embryo during embryogenesis?
Mesenchyme
What is reticular CT made up of?
T3 collagen and fibroblasts
Reticular CT has _____ collagen, _____ cells, and ____ GS
Increased
Moderate
Moderate
What kind of CT provides a framework for tissues like bone marrow, spleen, lymph nodes, etc?
Reticular CT
