Organs of the Endocrine System

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The endocrine system in the human body influences nearly all organs, cells and function in the body. It plays a critical role in growth and development, metabolism, sexual function, regulating mood, tissue function and reproductive processes. In a nutshell, this body system is the main player in slowly occurring body processes. The nervous system is in charge of the faster processes. It is important to fully understand the individual organs of the endocrine system and their functions to understand how this body system works as a whole.


This gland is located toward the lower area of the central brain. It is a collection of specialized cells and is the main link between the nervous system and the endocrine system. Nerve cells in this gland produce chemicals that control the pituitary gland. These chemicals will either suppress or stimulate pituitary hormone secretions.


This gland is literally about the size of a pea. It is located at the brain’s base just under the hypothalamus. It is considered the king of the endocrine system. This “master gland”, as it is referred to, produces hormones that are responsible for controlling many other endocrine glands. Seasonal changes, emotions and a variety of other facts influence the secretion and production of pituitary hormones. This is done by the brain sensing information and then the hypothalamus providing this information to the pituitary. The pituitary is two parts: the posterior lobe and the anterior lobe. The anterior lobe regulates adrenal, thyroid and reproductive gland activity. It also produces a variety of hormones, such as prolactin, corticotropin, growth hormone and thyrotropin. Endorphins are also secreted by this gland, and it controls a woman’s menstrual cycle and ovulation. The posterior lobe releases the antidiuretic hormone and this is responsible for controlling water balance in the body. It also produces oxytocin, which is responsible for stimulating contractions during childbirth.


The thyroid gland is located in the lower neck in the front. It looks almost like a butterfly and produces the hormones triiodothyronine and thyroxine. These hormones are responsible for controlling how quickly cells burn the fuels from food to create energy. Thyrotropin controls thyroid hormone production and release. The pituitary gland secretes it.

Adrenal Glands

The body has two of these, one on top of each kidney. They are triangular in shape and have two parts. The adrenal cortex, or outer part, is responsible for producing corticosteroids. These regulate or influence water and salt balance in the body, metabolism, sexual function and development, the body’s response to stress and the immune system. The adrenal medulla, or inner part, produces epinephrine and other catecholamines. Epinephrine, also referred to as adrenaline, increases heart rate and blood pressure during times of stress.


These four tiny glands are attached to the thyroid and together they work to release the parathyroid hormone. This hormone is responsible for regulating calcium levels in the blood with the assistance of calcitonin. The thyroid produces calcitonin.


This gland can be found in the mid-brain. It secretes a hormone known as melatonin, that may play a role in regulating a person’s sleep-wake cycle.

Reproductive Glands

While most are unaware, both males and females have gonads, the primary source of sex hormones. As one of the organs of the endocrine system, the testes, or male gonads, are found in the scrotum and secrete testosterone and other androgens. Testosterone is responsible for many things, including puberty changes. The ovaries, or female gonads, are found in the pelvis. They secrete the hormones estrogen and progesterone and produce eggs.


TeensHealth from Nemours. (2011). Endocrine System. Retrieved on March 16, 2011 from TeensHealth from Nemours:

University of Cincinnati Clermont College. (2004). Endocrine System. Retrieved on March 16, 2011 from University of Cincinnati Clermont College: