Hypothalamus hormones

Chronic activation of this survival mechanism impairs health A stressful situation — whether something environmental, such as a looming work deadline, or psychological, such as persistent worry about losing a job — can trigger a cascade of stress hormones that produce well-orchestrated physiological changes. A stressful incident can make the heart pound and breathing quicken. Muscles tense and beads of sweat appear. This combination of reactions to stress is also known as the "fight-or-flight" response because it evolved as a survival mechanism, enabling people and other mammals to react quickly to life-threatening situations. The carefully orchestrated yet near-instantaneous sequence of hormonal changes and physiological responses helps someone to fight the threat off or flee to safety. Unfortunately, the body can also overreact to stressors that are not life-threatening, such as traffic jams, work pressure, and family difficulties. Over the years, researchers have learned not only how and why these reactions occur, but have also gained insight into the long-term effects chronic stress has on physical and psychological health. Over time, repeated activation of the stress response takes a toll on the body. Research suggests that chronic stress contributes to high blood pressure, promotes the formation of artery-clogging deposits, and causes brain changes that may contribute to anxiety, depression, and Sounding the alarm The stress response begins in the brain (see illustra...

Overview of Hypothalamic and Pituitary Hormones The pituitary gland is often portrayed as the "master gland" of the body. Such praise is justified in the sense that the anterior and posterior pituitary secrete a battery of hormones that collectively influence all cells and affect virtually all physiologic processes. The pituitary gland may be king, but the power behind the throne is clearly the hypothalamus. As alluded to in the last section, some of the neurons within the hypothalamus - neurosecretory neurons - secrete hormones that strictly control secretion of hormones from the anterior pituitary. The hypothalamic hormones are referred to as releasing hormones and inhibiting hormones, reflecting their influence on anterior pituitary hormones. Hypothalamic releasing and inhibiting hormones are carried directly to the anterior pituitary gland via As an example, thyroid-releasing hormone from the hypothalamus binds to receptors on anterior pituitary cells called thyrotrophs, stimulating them to secrete thyroid-stimulating hormone or TSH. The anterior pituitary hormones enter the systemic circulation and bind to their receptors on other target organs. In the case of TSH, the target organ is the thyroid gland. Clearly, robust control systems must be in place to prevent over or under-secretion of hypothalamic and anterior pituitary hormones. A prominent mechanism for control of the releasing and inhibiting hormones is The following table summarizes the major hormones synthesi...

Compassionate Eye Foundation / Paul Bradbury / OJO Images Ltd / Getty Images Where Is the Hypothalamus Located? If you drew a line from the middle of your eyebrows directly back to the center of your brain you would locate a pea-sized structure called the hypothalamus. What this part of the brain lacks in size it makes up for in function. What Does the Hypothalamus Do? Think of the hypothalamus as the "smart home control system" of your body. Its primary responsibility is to keep your body functions well balanced and stable. The hypothalamus controls and coordinates much of your body’s involuntary functions like temperature regulation, hunger, thirst, sleep, and mood. By acting in response to input from the brain and from other hormone-producing centers in the body, the hypothalamus adjusts the body’s internal balance or homeostasis. Menstrual Cycle Control Your hypothalamus produces a hormone called GnRH or gonadotropin-releasing hormone. Under normal conditions, your body releases GnRH in a pulsatile fashion. This intermittent release causes the pituitary gland to coordinate the release of two other hormones called FSH or follicle stimulating hormone and LH or luteinizing hormone. FSH, in turn, stimulates the ovary to produce estrogen and LH stimulates the ovary to produce progesterone. The cyclic changes of these hormones are responsible for your When Things Go Wrong Since the hypothalamus is the control panel of your menstrual cycle, certain conditions that disrupt the...

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