one that involves damage to the calyces. Overall, urinary obstruction is the most frequent cause of this condition resulting in permanent dilation of the renal pelvis. Figure 3. Dilated Pelvis. The gross presentation of a kidney with a dilated pelvis due to chronic pyelonephritis. There was a positive correlation between a bright red inner surface of the kidney and acute tubular necrosis. Acute tubular necrosis was previously defined (see first primary correlation for the kidney). The bright red inner areas were most likely areas of necrosis that received insufficient amounts of the embalming fluid and, subsequently, experienced autolysis. Acute tubular necrosis is a common contributing factor in the renal failure patient, and this relationship between the gross and histologic observation is most likely non-specific to severe renal injury. Fine granularity of the cortical surface was positively correlated with both arteriolosclerosis and glomerulosclerosis. This condition is called nephrosclerosis (Kumar et al. 2104) (Figure 4). Arteriolosclerosis involves the proliferation of the endothelial cells of small arteries and arterioles in the kidney or the deposition of hyaline deep to the endothelial layer in the same vessels (Figure 5). Hypertension is a common cause of arteriolosclerosis, inducing arterial remodeling and the deposition of extracellular proteins such as hyaline. In early phases, arteriolosclerosis does not impair blood flow within the affected vessels. However, as the disease progresses, the blood vessel’s ability to remodel is reduced and the lumen may become obstructed. The obstruction results in decreased blood flow to the glomerulus, renal tubules, or both depending on the location and severity of obstruction. The destruction of the small blood vessels in the cortex causes continued on next page A New Resource for Integrated Anatomy Teaching: The Cadaver’s Kidney PG (Pathology Guide) 36 • HAPS Educator Journal of the Human Anatomy and Physiology Society December 2017 Winter Edition atrophy and fibrosis of the cortex that causes changes in the cortical surface of the organ seen as a fine granularity. The subsequent damage that results from arteriolosclerosis is varied, although glomerulosclerosis is a common disease that accompanies arteriolosclerosis. This is probably why glomerulosclerosis was also positively correlated with the appearance of a granular cortical surface. Glomerulosclerosis is a term that means sclerosis, or scarring, of the glomerulus. Infection, which causes glomerulonephritis, is a common cause of glomerulosclerosis, as is diabetes, reflux nephropathy, and drug toxicity (Kumar et al. 2014). Glomerulosclerosis can be focal, which means that it only affects some of the glomeruli, or global which means that it affects the glomeruli more diffusely. The end effect of glomerulosclerosis regardless of its cause is decreased functioning renal tissue, induces changes within the kidney’s normal architecture. Compensatory mechanisms involve enlargement of the still functioning glomeruli and shortterm increases in the glomerular filtration rate. Although glomerulosclerosis often accompanies arteriolosclerosis, because it can be a result of disease progression, the granularity of the surface is most likely a result of fibrotic scarring of the cortex due to small vessel damage than it is a result of damage to the glomeruli. Figure 4. Nephrosclerosis. The cortical surface of the kidney has a fine granularity in nephrosclerosis. Figure 5. Arteriolosclerosis. In the center of the photomicrograph, there is a glomerulus with a sclerotic arteriole. Generation of the guide To assist individuals who are dissecting in the gross anatomy laboratory, it was pertinent to explain the common gross abnormal appearances of the kidney regardless of whether the abnormal appearances were due to pathology or artifact. The surface of the cortex can be considerably variable, and this variability can be used to estimate the general level of renal health. Although the estimation of renal health is nonspecific, the presence of smoothness can direct the observer to a conclusion that the kidney was not under chronic stress. The presence of fine granular imperfections may point the observer towards the conclusion that the kidney was under some sort of chronic vessel destruction, such as arteriolosclerosis. The presence of deeper surface distortions may indicate a larger chronic issue (chronic pyelonephritis, diabetic nephropathy) or the presence of tumors, all of which can be confirmed by other findings. If the observer does not have the ability to histopathologically confirm a diagnosis, then at least the general categorization of the surface features may give them more information toward the cadaver’s overall renal health. In addition to the cortical surface features, the presence of red discolorations, both bright red and the more subdued red splotches, can be an indication of acute kidney injury. Although the red discolorations are not histologically different from the normally pigmented cortex, grossly these areas are very noticeable. The gross observation may be an indication, according to the statistical support, that the kidney incurred a non-specific acute insult. As in other organs, the presence of hard lesions is an indication of tumors, although the type of tumor will not be identifiable without histopathologic confirmation. Other characteristics that accompanied