Fibers

Question 1

Elastic Fibers

Answer 1

Primary function(s): Permit tissues to be stretched or distended and then return to their original shape or form.
Distribution: either arranged as elastic fibers (usually interwoven with collagen fibers in the CTs: Dermis, lung, blood vessels. or arranged as elastic sheets (ie elastic arteries like the aorta) At the gross level their large bundles look yellow in color, like that of the ligamentum flavum.
Specific Stains and LM appearance: Orcein Black, typically thinner than collagen fibers and arranged in a branching pattern (collagen fibers do not branch. In tissue spreads, often look like "rubber bands" that have stretched than recoiled. 
EM Appearance: Elastin core with fibrillin microfibrils. 
Clinical Correlations: Marfan's Syndrome = abnormal elastic fibers, predominant problems where high [elastic fibers]: aorta, skin, ligaments, suspensory ligaments of the lens. Joint hypermobility, Rupture: lens of the eye, Dilation/dissection of the aorta (aneurysm)

Question 2

Collagen Type I

Answer 2

Primary function(s):
Distribution:
Specific Stains and LM appearance:
EM Appearance: 
Clinical Correlations:

Question 3

Collagen Type II

Answer 3

Primary function(s):
Distribution:
Specific Stains and LM appearance:
EM Appearance: 
Clinical Correlations:

Question 4

Collagen Type III

Answer 4

Primary function(s):
Distribution:
Specific Stains and LM appearance:
EM Appearance: 
Clinical Correlations:

Question 5

Collagen Type IV

Answer 5

Primary function(s):
Distribution:
Specific Stains and LM appearance:
EM Appearance: 
Clinical Correlations:

Question 6

Collagen Type VII

Answer 6

Primary function(s):
Distribution:
Specific Stains and LM appearance:
EM Appearance: 
Clinical Correlations: