Loose Connective Tissue

Types of Loose Connective Tissue

1. Areolar Connective Tissue

   • Most widely distributed connective tissue.
   • Provides support for all other tissue types.
   • Acts as a universal packing material between tissues (e.g., epithelial, connective, muscle layers).
   • Functions:
     • Reservoir for water and salts.
     • Stores nutrients (primarily as fats, although capacity is lower than adipose tissue).
     • Defends against infection by creating a physical barrier.
     • Soaks up excess fluid during inflammation, leading to edema.
   • Structure:
     • Loose arrangement of elastic fibers (elastin) and non-elastic fibers (collagen).
     • Built by fibroblasts.
     • Dominated by proteoglycans in ground substance.
     • Example: Lamina propria separating epithelium from lower tissues.

2. Adipose Tissue

   • Divided into two subcategories: White Fat and Brown Fat.

   White Fat

   • Composition:
     • Similar to areolar but with higher fat storage density.
     • More cells (adipocytes) compared to areolar.
     • Richly vascularized to aid nutrient storage and release.
   • Functions:
     • Fat storage.
     • Insulation and shock absorption (e.g., around breast tissue to protect mammary glands).

   Brown Fat

   • Less densely packed than white fat.
   • Lipids used specifically for maintaining body temperature (thermal regulation).
   • Energy not used for ATP generation.

3. Reticular Connective Tissue

   • Similar composition to areolar
   • Dominated by reticular fibers instead of elastin and collagen.
   • Provides more flexibility and movement.
   • Found around organs like the spleen, allowing some motion.
   • Assembled by reticular cells.
   • Supports blood cells in the lymphatic system (lymph nodes, spleen, bone marrow).
   • Important for the function of the lymphatic system.