Human Anatomy and Physiology 2
Growth Hormone and Thyroid hormones
Growth hormone is produced and secreted by the anterior pituitary gland. This hormone was once believed to be of importance only during periods of active growth, but it is now recognized that adults produce nearly as much GH as children (Adams and Koch, 2009).GH stimulates the liver to produce sommatropins that then targets a variety of cells. Although its major targets are bone and skeletal muscle, GH stimulates many types of body cells to increase in size and replicate. It is considered an anabolic hormone. GH is stimulated by gonadotropin-releasing hormone and inhibition occurs when there is negative feedback from growth hormone. GH is a peptide hormone. GH enters the target cell with the aid of a second messenger. There are a long number of secondary factors, such as exercise and sleep that influence the stimulation of GH. Some factors that increase the release of GH include; clonidine, stress, trauma, vigorous exercise, elevated body temperature, and androgens and estrogens. Some factors that decrease the release of GH include; carbohydrate-rich diet, obesity, free fatty acids, and increased serum glucose level (Adams and Koch, 2009). Thyroid-stimulating hormone (TH) controls the secretion of thyroid hormones and targets the thyroid gland. TH is a peptide hormone. Thyroid hormone is produced in the thyroid. It is stimulated by the thyroid-stimulating hormone from the thyroid gland and inhibition occurs when there is negative feedback from thyroid hormone. TH triggers the liver and, enters target cells by means of an energy-dependent transport system and by sending second messengers. (Martini and Nath, 2009). Both Thyroid hormones and GH accelerate metabolism in several ways. They promote normal growth of bones and increase growth hormone output. They increase the rate of lipid synthesis and mobilization. They enhance cellular uptake of amino acids and increased protein synthesis.They...
Please join StudyMode to read the full document