Hypertensive kidney disease this situation, the kidney supplied blood by the narrowed renal artery suffers from inadequate blood flow, which in turn causes the size of the kidneys to decrease. Other consequences include arterial stiffening, which involves a gradual breakdown of elastic fibers and intima (the innermost layer of a blood vessel) thickening. An alternative mechanism of hypertensive nephropathy is prolonged glomerular hypertension and hence glomerular hyperfiltration. These can occur simultaneously but not necessarily. The idea is that hypertension results in sclerosis of the glomeruli which ultimately means reduced kidney function. As a compensatory mechanism, the unaffected nephrons (specifically, the preglomerular arterioles) vasodilate
Posterior spinal artery anastomosis around the posterior roots of the spinal nerves, and communicate, by means of very tortuous transverse branches, with the vessels of the opposite side. Close to its origin each posterior spinal artery gives off an ascending branch, which ends ipsilaterally near the fourth ventricle. The posterior spinal artery can often originate from the posterior inferior cerebellar artery, rather than the vertebral. Most cranially, the posterior spinal artery supplies the dorsal column of the closed medulla containing fasiculus gracilis, gracile nucleus, fasciculus cuneatus, and cuneate nucleus. At the spinal cord level, the posterior spinal artery supplies the dorsal and lateral