Differentiating Connective Tissue Proper

Key Concepts

• Fiber Types:

  • Collagen: Thickest fiber type.
  • Elastic: Medium thickness.
  • Reticular: Finest fiber type.

• Staining:

  • Collagen and elastic fibers often stained pink/purple.
  • Reticular fibers require special stains, often not visible with common ones.

Types of Connective Tissue Proper

1. Adipose Tissue

• Description:
  • Composed of fat cells (adipocytes).
  • Each fat cell appears as a bubble filled with fat.
• Common Confusion:
  • Often mistaken for simple squamous due to open space.

2. Areolar Connective Tissue

• Characteristics:
  • Contains pink collagen fibers and black/purple elastic fibers.
  • Fibers arranged randomly in various directions.
  • Contains many fibroblasts (black dots).

3. Reticular Connective Tissue

• Characteristics:
  • Contains reticular fibers that resemble a net.
  • Requires special staining to visualize.
  • Commonly found in lymph nodes, indicated by circular cells.

4. Dense Regular Connective Tissue

• Characteristics:
  • Fibers running in one direction (light pink fibers).
  • Cells (fibroblasts) are compressed between fiber bundles.

5. Dense Irregular Connective Tissue

• Characteristics:
  • Fibers arranged in many directions.
  • Appears as cut bundles of fibers, stained light pink.

6. Elastic Connective Tissue

• Characteristics:
  • Wavy elastic fibers in the foreground, over a background of pink collagen.
  • Not to be confused with elastic cartilage.

Practice Questions Overview

1. Dense Regular Connective Tissue:
   • Identified by fibers going in one direction, pink collagen, and fibroblasts.
2. Adipose Tissue:
   • Identified by bubbles of fat cells.
3. Reticular Connective Tissue:
   • Identified by net-like black fibers.
4. Dense Irregular Connective Tissue:
   • Appears like hamburger meat with fibers going in every direction.
5. Areolar Connective Tissue:
   • Identified by black fibers in various directions and many fibroblasts.
6. Simple Squamous:
   • Confused with adipose due to open space but has multiple nuclei.
7. Elastic Connective Tissue:
   • Identified by purple wavy fibers over a collagen background.
8. Dense Regular Connective Tissue (again):
   • Fibroblasts compressed between pink collagen fibers.
9. Elastic Connective Tissue (again):
   • Wavy elastic fibers over pink collagen.
10. Areolar Connective Tissue (again):

• Fibers in many directions with visible fibroblasts.