Major Endocrine Glands

pituitary gland

located in the sella turcica of the sphenoid bone. It consists largely of two functional lobes,

anterior pituitary

controls the activity of many other endocrine glands, it is sometimes called the master endocrine gland.

posterior pituitary

is not an endocrine gland, because it does not synthesize the hormones it releases. Instead, it acts as a storage area for two neurohormones transported to it via the axons of neurons in the paraventricular and supraoptic nuclei of the hypothalamus.

pineal gland

small cone-shaped gland located in the roof of the third ventricle of the brain. Its major endocrine product is melatonin, which exhibits a diurnal (daily) cycle.

thyroid gland

composed of two lobes joined by a central mass, or isthmus. It is located in the anterior neck, just inferior to the larynx.

parathyroid glands

found embedded in the posterior surface of the thyroid gland. Typically, there are two small oval glands on each lobe, but there may be more and some may be located in other regions of the neck.

thymus

bilobed gland situated in the superior thorax, posterior to the sternum and overlying the heart. Conspicuous in the infant, it begins to atrophy at puberty, and by old age it is relatively inconspicuous.

adrenal glands

located atop the kidneys

adrenal medulla

develops from neural crest tissue, and it is directly controlled by the sympathetic nervous system.

pancreas

located behind the stomach and close to the small intestine, functions as both an endocrine and exocrine gland. It produces digestive enzymes as well as insulin and glucagon, important hormones concerned with the regulation of blood sugar levels.

ovaries

paired, almond-sized organs located in the pelvic cavity, produce two steroid hormone groups, the estrogens and progesterone.

testes

suspended in a pouchlike sac, the scrotum, outside the pelvic cavity.