Endocrine glands are glands of the endocrine system that secrete hormones directly into the blood rather than through a duct. The parathyroid glands secrete parathyroid hormone (PTH) which causes an increase in blood calcium levels by targeting bone, the intestine, and the kidneys. The adrenal glands (also known as suprarenal glands) are endocrine glands that are responsible for releasing hormones in response to stress through the synthesis of corticosteroids and catecholamines. Whereas, gonads like testes in male ovaries in female have an exocrine function such as the production of gametes and endocrine function of testosterone, estrogens and progesterone production respectively. Pancreas also have the dual function. As an exocrine gland they secrete pancreatic juice and as an endocrine gland, they produce insulin and glucagon hormones.