Topic 15 - Connective tissue : extracellular matrix (ground substance and fibers)

Question 1

-Ground substance:

Answer 1

Highly hydrates gel which surround cells and fibers. Composed of proteoglycan and GAG´s bound to a protein core.

Question 2

-Fibers:

Answer 2

connective, elastic, collagen or reticular

Question 3

Connective fibers
synthesis
properties
staining

Answer 3

Collagen -most abundant protein
Synthesis: Fibroblast RER synthexised procollagen wich is then transportet to the gogli. transformed into tropocollagen - form collagen fibers in the ECM
Properties: non branching of changinge thickness, can be streached to 5% of their initial lenght. poor shearing strengt
Staining: azan staining selectively stains collagen blue.

Question 4

Elastic fibers
synthesis
properties
staining

Answer 4

present in organs whose normal function requires elasticity in addition to tensile strenght, lungs arteries and veins.
Synth: Fibriblast RER synth. tropoelastin molecules into elastin. cross linked and assembled in extracelular space.
Prop: can be streched to 2.5x lenght fibres can be individual branching og anastomosing
Staining: resorcin fushin

Question 5

Reticular fibres
synthesis
properties
staining

Answer 5

individual collagen fibres coated with protoglycans and glycoproteins.
synt: fobroblast RER as collagen III fibrils
Prop: form flexible networks around capillaries, mucle fibres, nerves, adipose cells.
staining: silver impregnation
occ: around ducts