Human Adrenal (H&E) [#117, 118]: Is covered by a thick connective tissue capsule. The gland is divisible into an outer prominent cortex and an inner relatively inconspicuous medulla. Observe that the cortex is composed of three zones and that each has a distinct organization of the parenchyma. The outer zone called the zona glomerulosa consists of columnar cells that are packed in ovoid or spherical groups beneath the capsule. The middle zone is the most prominent part of the cortex and is called the zona fasciculata. This is composed of polyhedral cells that are arranged in cords or fascicles that run parallel to each other with a marked radial orientation in relation to the entire gland. The cells of this zone are frothy or spongy in appearance due to loss of stored lipids during preparation of the slide. These cells are therefore often called spongiocytes. The innermost zone of the cortex is the zona reticularis. Notice that the cells here are arranged in a reticulum of cords. The nucleus is intensely heterochromatic (or pyknotic). The cytoplasm of these cells stains deeply with eosin and frequently shows the presence of yellowish brown lipofuscin pigment granules.