Plasma cells are highly efficient producers of antibodies. Although most are located in lymphatic tissues like lymph nodes, they do occur in loose c.t. areas. Plasma cells, like lymphocytes, possess a well-defined, spherical shape with rounded nuclei . Mast cells release histamine and heparin. These chemical agents induce the vascular responses that cause inflammation.
Mast cells are fragile, granular cells that can rupture during tissue preparation and staining.
During tissue preparation for staining fats are leached from these cells by alcohols. In most stained slides, they appear as spherical, empty cells with nuclei pushed to the periphery. Think of the mesenchyme cell as the precursor to fibroblasts, chondroblasts, and osteoblasts. Areolar connective tissue is abundant and typically found in most body locales. As the underlying connective tissue to most epithelia it is a key component of membranes .