Also find a mast cell in the lamina propria. Its cytoplasm is filled with small, dark purple, evenly sized, regularly shaped granules. This is an example of loose connective tissue, defined by moderately abundant, loosely interwoven fibers, and a large proportion of cells. In contrast, the submucosa is a good example of dense connective tissue. Dense connective tissue is defined by abundant and densely packed fibers, and a much smaller proportion of cells.
Fibroblasts are the main producers of collagen and ground substance in connective tissues.
A network of nerve cells and fibers called Meissner's plexus is located in the submucosa. W90a lymph node, human Go to link 2 and click the Mouse-over button. Move the cursor around to find the capsule, subcapsular sinus, cortex and medulla. The two major cell types within the cortex and medulla of the lymph node in this slide are lymphocytes and macrophages. The macrophages have ingested carbon particles that appear as black granules in the cytoplasm.