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Correct Answer: growth hormone
the correct answer to the question is growth hormone. the anterior pituitary, also known as the adenohypophysis, is a major gland in the endocrine system that produces and secretes several crucial hormones. these hormones include growth hormone (gh), prolactin, thyroid-stimulating hormone (tsh), adrenocorticotropic hormone (acth), luteinizing hormone (lh), and follicle-stimulating hormone (fsh).
growth hormone (gh), specifically, plays a vital role in growth, body composition, cell repair, and metabolism. it stimulates the liver to produce an insulin-like growth factor (igf-1), which promotes the growth of bone and other tissues. this hormone is not only crucial during childhood and adolescence for height growth but also affects fat distribution and muscle mass in adults.
unlike thyroxine, which is secreted by the thyroid gland, gh is produced directly by the anterior pituitary. the secretion of gh is regulated by the hypothalamus through the release of growth hormone-releasing hormone (ghrh) and growth hormone-inhibiting hormone (somatostatin). these hormones tell the pituitary gland when to start and stop releasing gh.
gh also has effects that counteract insulin, thus raising the blood glucose levels. it decreases the uptake of glucose by cells and increases both the breakdown of fat (lipolysis) and the production of glucose by the liver. this can provide the necessary energy for growth processes, particularly during times of stress or fasting.
in contrast, other hormones listed, such as epinephrine and glucagon, are secreted by the adrenal medulla and pancreas, respectively, and not by the anterior pituitary. epinephrine plays a significant role in the body's fight-or-flight response, while glucagon helps to increase glucose levels in the bloodstream by breaking down stored glycogen in the liver. neither of these functions is directly related to the role of gh.
therefore, when comparing the listed options, growth hormone is the only hormone among them that is secreted by the anterior pituitary, making it the correct answer to the question.
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