Figure 6.

Photomicrographs comparing the intracerebral extrinsic and intrinsic microvascular compartments of a newborn (A) and adult (B) human brains. The reproduction in (A) is from a rapid Golgi preparation of the motor cortex of a newborn infant and that in (B) is from an intravascular casting of an adult human brain, from the work of Duvernoy et al. (1981). Despite the significant differences in brain size weight (newborn ca. 410 g and adult ca. 1,350 g) the overall dimension, vascular composition and structural organization of their intracerebral extrinsic and intrinsic microvascular compartments are remarkable similar. These structural and organizational similarities mirror the similar developmental and physiological constrains that endure through the prenatal and postnatal functional maturations of cortical neurons Marín-Padilla (2011). In both brains (A, B), there are more intrinsic capillaries with smaller intercapillary spaces in the gray matter than in the white matter. The abundant of intrinsic capillaries through the cortex gray matter protect the functional activity of its neurons, in both normal and abnormal conditions. Key (A): I, first lamina; GM, gray matter; WM, white matter; A and V, arterial and venous vessels; and in (B) 6, pial vein; 5, venule; 1, arteriole; 3, deep arteriole; 2, recurrent arteriole.