Adrenal gland. Fluorescence deconvolution micrograph of a section through an adrenal gland, showing the zona glomerulosa and zona fasciculata. Cell nuclei are blue, endothelial nitric oxide synthase enzymes are red, and actin proteins are green/yellow. The adrenal glands are found on top of the kidneys. They are part of the endocrine system, producing stress hormones and releasing them into the bloodstream.