These hormones produce a ‘ flight-or-fight‘ response. It contains chromaffin cells, which secrete catecholamines (such as adrenaline) into the bloodstream in response to stress.
The medulla lies in the centre of the gland, and is dark brown in colour. Fig 3 - Histological appearance of the cortex and medulla of the adrenal gland. Fig 2 - Posterior view of the abdomen, demonstrating the anatomical relations of the adrenal glands. It also secretes a small amount of corticosteroids. It also secretes a small amount of androgens. Functionally, the cortex can be divided into three regions (superficial to deep):
It secretes two cholesterol derived hormones – corticosteroids and androgens. The cortex and medulla synthesise different hormones. They are two separate endocrine glands, with different embryological origins: The outer cortex and inner medulla are the functional portions of the gland.
The adrenal glands consist of an outer connective tissue capsule, a cortex and a medulla. Veins and lymphatics leave each gland via the hilum, but arteries and nerves enter the glands at numerous sites.
