Loose

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Stephen E. Fish, Ph.D. Mitchell L. Berk,
Ph.D. Marshall University J. C. E. School of
Medicine
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Note to instructors I use these PowerPoint
slides in histology lectures that I give to first
year medical students. Copy the slides, or just
the images into your own teaching media. We all
know that teaching science often requires
compromises and simplification for specific
student populations, or the requirements of a
specific course. Please feel free to offer
suggestions for improvements, corrections, or
additional illustrations. I would be pleased to
hear from anyone who finds my work useful, and am
always willing to make it better. Also, the
images have been compressed to screen resolution
to keep PowerPoint file size down, and I can
provide them at any resolution. Contact me about
the illustrations and Mitchell L. Berk about the
photomicrographs. Stephen E. Fish,
Ph.D. Fish_at_Marshall.edu Berk_at_Marshall.edu
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Loose Dense irregular, Regular Connective
Tissue
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Construction of proteoglycans
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Collagen types that assemble into fibrils with a
banded pattern in EM
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Elastin Elastin stain only HE
plus elastin stain
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Loose irregular CT

• Contains capillary beds throughout body
• Diffusion in amorphous ground provides waste and
  nutrients exchange with capillaries
• Is where immune cells stand guard

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GAGs collagen in loose CT
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Loose CT in HE
Gland
Gland
Capillaries
Loose CT
Fine caliber collagen fibers
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Loose CT- nuclei are fibroblasts Immune cells
What is this stuff?
What type of epithelia is this?
Loose CT (nuclei are Immune cells)
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Lamina propria in small intestine villi is loose
ct
(What is the epithelia?)
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Loose CT in mesentary (areolar CT) whole mount
Collagen
Elastin
Mesothelial cell
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CT cells from Mesenchyme
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Cells derived from hematopoiesis
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Loose CT
Lymphocytes
Whats this?
Testable Plasma cell
Fibrocytes
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Loose CT (special stain)
Mast cells
Fibrocytes
Note elastin compared to collagen
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NOTE that collagen fibers are narrower than
nuclei present
Loose CT
Lymphocytes
Probable Mast cell
Fibrocytes
Macrophage convention
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Many plasma cells
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White blood cells found in CT
Eosinophil
Monocyte
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White blood cell escape into CT from capillaries
small veins
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Dense irregular CTThe only nuclei visible here
are fibroblasts fibrocytes NOTE that collagen
fibers are wider than nuclei
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Compare loose to dense in the dermis
Loose CT
Dense CT
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Dense irregular regular CT
NOTE fibrocytes in rows
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Sherman says
I like dense irregular CT chew toys