Chapter 19 - Adrenocortical Function

Abstract

This chapter discusses the functions of adrenal glands. In mammals, the adrenal glands are bilateral structures located craniomedial to the kidneys. The adrenal is made up of two glands of different embryological origin. The center of the gland, the medulla, comprises coalesced chromaffin cells of neuroectodermal origin that secrete epinephrine or norepinephrine. The surrounding adrenal cortex arises from mesoderm, and can be divided histologically into three zones: zona glomerulosa, zona fasciculate, and zona reticularis. The cells of the zona glomerulosa are arranged in ovoid groups immediately inside the connective tissue capsule. A notable feature of the ferret adrenal gland is that islands of cortical cells can be found among cells of the medulla. These cells resemble those of the inner part of the zona fasciculata. In birds, the adrenal glands are also separate, encapsulated organs. The glands lie cranial to the kidney, wholly or partly covered by the gonads. This chapter begins with discussing the physiology of adrenocortical hormones. The chapter then presents details of different adrenocortical diseases. The chapter concludes with a discussion on adrenocortical functions.