Renal anatomy and basic concepts and methods in renal pathology

Abstract

Each kidney weighs approximately 150 g in adults, with ranges of 125 to 175 g for men and 115 to 155 g for women; both together represent 0.4% of the total body weight. Each kidney is supplied by a single renal artery originating from the abdominal aorta; the main renal artery branches to form anterior and posterior divisions at the hilus and divides further, its branches penetrating the renal substance proper as interlobar arteries, which course between lobes. Interlobar arteries extend to the corticomedullary junction and give rise to arcuate arteries, which arch between cortex and medulla and course roughly perpendicular to interlobar arteries. Interlobular arteries, branches of arcuate arteries, run perpendicular to the arcuate arteries and extend through the cortex toward the capsule (Fig. 1.1). Afferent arterioles branch from the interlobular arteries and give rise to glomerular capillaries (Fig. 1.2). A glomerulus represents a spherical bag of capillary loops arranged in several lobules (Fig. 1.3); the capillaries merge to exit the glomerulus as efferent arterioles, which, in most nephrons, branch to form another vascular bed, peritubular or interstitial capillaries, which surround tubules. Efferent arterioles from juxtamedullary glomeruli extend into the medulla as vasa recta, which supply the outer and inner medulla. The vasa recta and peritubular capillaries collect, forming into interlobular veins; the veins follow the arteries in distribution, size, and course, and leave the kidneys as renal veins, which empty into the inferior vena cava. © 2007 Springer New York.