L2.7.3: Dense & Loose

• • Collagen (or elastic) fibers are the main matrix.
  • Crowded between the collagen fibers are rows of fibroblasts (fiber-forming cells) that manufacture the building blocks of the fibers.
  • Located at ropelike structures that withstand tension in one direction:
  • Tendons: attach skeletal muscles to bones. REGULAR
  • Ligaments: connect bones at joints. REGULAR
  • Dermis: lower layers of the skin. IRREGULAR.
  • Regular Tissues — fibers are arranged in an orderly manner; parallel to each other.


  Dense Connective Tissue
• Softer, have more cells and fewer fibers than other connective tissues (except blood).


  Loose Connective tissue
• Loose connective tissue

  • Areolar connective tissue
  • Adipose connective tissue
  • Reticular connective tissue
• • Has the capacity to be absorbent.
  • Areola: small open space
  • “Body’s cotton”
  • Most widely distributed connective tissue.
  • Soft, pliable “cobwebby” tissue that cushions and protects the organs it wraps.
  • Functions as a universal packing tissue and connective tissue “glue” to hold organs in place.
  • Lamina propria – underlies all mucous membranes.
  • Its fluid matrix contains all types of fibers, which form a loose network.
  • Can absorb excess fluid
  • Can soak up excess fluid known as edema


  Areolar connective tissue
• • Commonly called fat. It is an avascular tissue.
  • Technically an areolar tissue in which adipose cells dominate.
  • These are spherical and globular in shape and its nuclei are on the side of the cell to give way to the lipids.
  • Function
  • Protects some organs
  • Serves as a site of fuel storage
  • Insulates the body
  • Location:
  • Subcutaneous tissue beneath the skin, where it insulates the body and protects it from bumps and extremes of both heat and cold.
  • kidneys and eyeballs.
  • Fat “depots” in the hips, breasts, and belly where fat is stored for fuel.


  Adipose connective tissue
• • Delicate network of interwoven fibers with reticular cells (like fibroblasts).
  • Modified collagen fiber that forms stroma (internal framework) of organs and provides structural support.
  • “Cellular bleachers”
  • Location:
  • Lymph nodes
  • Spleen
  • Bone marrow


  Reticular connective tissue