The Hypothalamus

An informative article on: The Hypothalamus.

Of the three endocrine glands located in the brain, the hypothalamus is the largest. It is considered to be a primary gland because it secretes many hormones that affect various functions. But even more importantly, it affects the pituitary gland that is the liaison between the hypothalamus and the central nervous system.

Location and Link to Central Nervous System

The hypothalamus is located at the central part of the base of the brain, and is the main link between the nervous and endocrine systems. It is best to view this link in terms of a chain reaction. The hypothalamus releases chemicals (hormones) that either causes hormones to be released by the pituitary gland, or it inhibits them from being released. The hormones released by the pituitary, in turn, cause a reaction in the central nervous system. Should any disorder of the hypothalamus cause too many or too few of these hormones from being released, there is a breakdown in communication between the endocrine and nervous systems.

Secretes Many Hormones

Most of the hormones secreted by the hypothalamus actually affect the pituitary gland with the most well known being oxytocin, growth hormone-releasing hormone (GHRH) and dopamine. Oxytocin actually works as a neural transmitter. It is most commonly known for the part it plays in the female reproductive system and is the ultimate cause of inducing labor. GHRH, or somatocrinin, causes the release of growth hormone while dopamine is another neurotransmitter that regulates emotion, movement, motivation and feelings of pleasure. Dopamine also is directly linked to addictions, chemical or behavioral.

Disorders of the Hypothalamus

Often it is extremely difficult to differentiate between a disease of the hypothalamus from a disease of the pituitary gland. The reason for this is due to their close proximity to each other as well as the inability to easily access these glands. Actually, the only way to ascertain with any amount of certainty as to whether a dysfunction is in one or the other of the glands is to measure levels of specific hormones in the bloodstream. However, there are other times when even these tests make it difficult to make an accurate diagnosis.

Hypothalamic Tumors

In adults, hypothalamic tumors are most often metastasized from cancers in other locations throughout the body, while in children they are the result of abnormal growth of glial cells in the nerve endings. Symptoms of these tumors include loss of appetite, loss of body fat, sensations of euphoria, headaches and hyperactivity. Some hypothalamic tumors may interfere with vision while others may result in seizures. In children, these tumors can promote precocious puberty.

There are just so many functions in the body that are directly proportionate to the hormones, or lack of hormones, secreted by the hypothalamus. Because these hormones affect both the pituitary gland as well as the central nervous system, the hypothalamus is one of the major glands of the endocrine system.