The kidneys are paired retroperitoneal organs that lie at the level of the T12 to L3 vertebral bodies. The renal parenchyma has two layers: cortex and medulla. The renal cortex lies peripherally under the capsule while the renal medulla consists of 10-14 renal pyramids, which are separated from each other by an extension of renal cortex called renal columns. Learn here: http://radiopaedia.org/articles/kidneys
AreolarConnectiveTissueSkin:Some of the dark dots in the images are the nuclei of areolar connective tissue cells. The most common cell type is the fibroblast, but areolar connective tissue also contains macrophages, mast cells, and white blood cells.