The Hypothalamus Sitting on top of the pituitary gland, the hypothalamus monitors body systems and makes adjustments to those systems through the pituitary gland, which is suspended just below it. It actually controls both the pituitary gland and the pineal gland . This "master thermostat" is really a traffic cop and body monitor, instructing all the critical hormonal subsystems and glands to maintain body systems within biological ranges through instructions to the pituitary gland. The pituitary gland secretes the necessary hormones to the other glands in the endocrine system.   Details on the interaction Process: For the pituitary gland, hypothalamic releasing and inhibiting hormones are carried directly to the anterior pituitary gland via hypothalamic-hypophyseal portal veins. Specific hypothalamic hormones bind to receptors on specific anterior pituitary cells, modulating the release of the hormone they produce. Depending on the messages it receives in the form of hormone levels, temperature levels, blood pressure levels, or stressors, it in turn will secrete hormones to notify the pituitary and pineal gland to moderate whatever is ouside the norms it recognizes. It responds by either nerve impulses or with needed hormones. The hypothalamus' main function is homeostasis, or maintaining the body's status quo; however, by controlling the pituitary and communicating directly to the pineal gland, it dominates the body's hormornal system, thus effecting metabolism, growth, and sexual processes. The connection to the pineal gland allows the pituitary gland to regulate sleep and wakefulness cycles, influencing moods and producing the physical "flight/fight" responses. ©1998-2009 Medical Central Online™, All Rights Reserved.