CHAPTER 9 - Structural and Biochemical Characteristics of Mast Cells

Abstract

This chapter discusses structural and biochemical characteristics of mast cells. Mast cells are found in loose connective tissue. With few exceptions, their presence in tissues and organs can be correlated to the connective tissue content. Cartilage and bone are devoid of mast cells, but the surrounding layers of dense connective tissue, the perichondrium and periosteum may contain a number of cells. Parenchymatous organs such as liver, kidney, and adrenals contain relatively little connective tissue and mast cells are rare in these organs. Organs rich in connective tissue are mammary glands, tongue, prostate gland, lung, and omentum, and these also contain a large numbers of mast cells. Mast cells also may be in evidence in large numbers in intramuscular connective tissue, in the various layers of the respiratory and gustatory tract, in serous membranes, and in skin. In humans and most other mammals, mast cells vary widely in shape and size. These cells are greatly influenced by surrounding tissue components. In loose or areolar connective tissue, they assume plump, rounded shapes, while in coarse fibrous tissue of skin or organ capsules, they may appear as elongated, almost filiform elements.