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Specific Function of the Endocrine Glands
PINEAL GLAND
The pineal gland is around the size of a pea and is located within the brain. The functions
of this gland are not fully known, but it seems to have a part in a person’s sexual development.
PITUITARY GLAND
The pituitary gland is about the size of an acorn. It weighs about 0.021 ounces and is
situated at the base of the brain. Because of the pituitary gland’s many regulatory functions, it is
often referred to as the “master gland”.
The pituitary gland has three lobes. The anterior lobe and the posterior lobe secrete
different hormones and have a great effect on the other glands. The intermediate lobe is still not
completely understood.
The Anterior Lobe of the Pituitary: The hormones that the anterior lobe releases
control a range of bodily functions by regulating the metabolic activities of cells and by
stimulating other endocrine glands. The anterior lobe produces at least 5 different hormones.
The Posterior Lobe of the Pituitary: The posterior lobe of the pituitary gland secretes
two hormones that are actually produced in the hypothalamus.
THYROID GLAND
The thyroid gland is the largest gland of the endocrine system. It is a twin mass,
consisting of a left and right lobe, located in the neck at the junction of the trachea and larynx. It
produces a hormone called thyroxin. Thyroxin contains iodine, which is necessary for normal
thyroid activity.
The metabolic action of thyroid hormones is very important during the growth years. A
lack of thyroid hormones is very important during the growth years. A lack of thyroid hormones
during the early growing years results in cretinism. This condition results in arrested growth,
mental retardation, slow heart rate, and dry, yellowish skin.
PARATHYROIDS
The four brownish – yellow parathyroid glands are the smallest glands of the endocrine
system. Two of them are located on the back – side of each lobe of the thyroid. The hormone
from these glands regulated the body’s calcium and phosphorus balance. These minerals are
necessary for growth as well as proper muscle contraction.
THYMUS GLAND
The thymus gland is like the pineal gland in that we aren’t sure what it does. It is
believed that the thymus gland plays and important role in the body’s immune system – possibly
setting up part of the system during infancy and childhood.
ADRENAL GLANDS
The two adrenal glands are located at the top of each kidney. The adrenal glands consist
of two parts – the outer portion, called the adrenal cortex, and the inner portion, called the
adrenal medulla.
Aldosterone is the principal, most potent hormone that the adrenal cortex produces. Its
function is to maintain the body’s water balance. Cortizone is produced by the inner layer of the
cortex. Cortizone works to control the metabolism of carbohydrates, fats, and proteins.
The adrenal medulla is highly dependent upon the hypothalamus and the autonomic
nervous system for regulation. It secretes the hormone epinephrine, more commonly called
adrenaline, which increases heart action, raises blood pressure, increases respiration, and
suppresses the digestive process.
THE ISLETS OF LANGERHANS
The pancreas is a gland that serves two systems; the digestive and the endocrine. The
major portion of the gland secretes a digestive juice that breaks down nutrients. The elongated,
flattened organ lies behind the stomach, attached to the first section of the small intestine by a
duct that transports its digestive juice to the intestine.
Scattered throughout the pancreas are many small clusters of cells that are separated from
those of the digestive pancreas by special fibers. These clusters make up the endocrine part of
the pancreas.
OVARIES AND TESTS
As endocrine glands, the ovaries and testes produce hormones that are responsible for the
development and maintenance of secondary sex characteristics (e.g. hair breasts) during
adolescence.