They are two glands located each at the upper end of each kidney . They measure about 5 cm. 2.5 cm long. wide and their shape resembles that of a triangle; they have a yellowish-brown color and weigh approximately 5 g. moon.
What are the adrenal glands?
They consist of two portions with different structure, functions and origin: the internal medullary portion and the external cortical portion .
The cortical part (also called the adrenal cortex, adrenal cortex or adrenal cortex) consists of three portions subsequently stratified from the outside. Each of them specializes in producing particular steroid hormones : the glomerular (outermost) region produces aldosterone and other mineralocorticoid hormones which are indispensable for regulating the hydrosaline exchange within the body; the collated portion (intermediate) produces cortisol , cortisone and corticosterone (glycocorticoids active on the glycidic exchange); the reticulated (innermost) one generates the sex hormones, – mainly of the androgen type – but also progesterone and estrogen .
The medullary (or medullary part of the adrenal) is located within the adrenal gland and is surrounded by the cortical portion . It consists of irregular cell cords that produce two catecholamines (neurotransmitters) – adrenaline and noradreanalin – whose production is activated only in specific situations.The secretion of hormones in the adrenal cortex, and specifically that of glycocorticoids , is controlled by the pituitary hormone ACTH .
What are the adrenal glands used for?
Their function is to secrete different hormones which are indispensable for the performance of multiple physiological functions. Their secretion is endocrine : what is secreted, that is , is directly introduced into the bloodstream (this type of secretion differs from the exocrine one, through which the product is introduced into a natural cavity of the organism or released to the outside , as happens with stomach gastric juices or tears).