Connective Tissue

Loose connective tissue (aka areolar tissue): loosely arranged fibers plus cells of various types. The cells are separated widely by intercellular ground substances. They are located under epithelia that cover the body surfaces and line the internal surfaces, as well as being associated with epithelium of glands, and surrounding blood vessels, muscles, and nerves. It also plays a role in immunity, inflammation, and diffusion of nutrients, oxygen, CO2, and waste.

Dense connective tissue: contains more collagen than cells. Include the following types:

Extracellular Matrix: complex and intricate structural network surrounds and supports cells within the connective tissue. It consists of fibers (collagen, elastic, and reticular) and ground substance (proteoglycans).

Collagen Fibers are made up of fine fibrils, which exhibit a 68 nm banding pattern due to precipitation of the TEM stain. They are the most abundant fibers of connective tissues, appearing wavy in LM. They stain easily with Eosin, and other acidic dyes. Collagen fibrils are assembled extracellularly.

Fixed cells of the connective tissue include the following: Wandering cells migrate from blood in response to stimuli. These include the following: