Light micrograph of a young human pineal gland showing incipient lobulation of the parenchyma. The pineal parenchyma tends to organize itself into rounded units separated by thin connective tissue septa where the blood vessels are located. However, unlike the true lobes present in the exocrine glands, these units are not fully delimited but rather merge extensively with neighbouring units. Although the distribution of the parenchyma in rounded units can be seen, the lobes are still poorly defined.