chapter  16
26 Pages

The Arterial Media as a Target of Structural and Functional Injury by Chemicals

ByPaul J. Boor, Daniel J. Conklin

The vasculature, which is a complex and highly integrated system of conduits, is

deceptively simple from the standpoint of the cellular composition of each

individual blood vessel. All vessels of the entire vasculature are composed, at

most, of only two cell types, the endothelial cell and the vascular smooth muscle

cell. Vessels of all sizes are also surrounded by the specialized supporting cells

and structures known as the adventitia. The space around capillaries, which

varies greatly from tissue to tissue, also contains an additional cell, the pericyte,

which is not contractile and about which relatively little is known. Large mus-

cular arteries, elastic arteries, and veins are surrounded by adventitial fibroblastic

cells and a great number of other specialized structures, including nervous tissue

and, in the case of large elastic arteries, vasa vasorum. Thus, while the basic

cellular components of blood vessels per se are simple, the characteristics of

these elements vary greatly from vessel to vessel and the integration of varying

types of blood vessel with adjacent structures is quite complex.