Thyroid gland - body of an endocrine system which is on front side of a neck. The thyroid gland synthesizes hormones under the influence of a hypophysis and a hypothalamus.
Instruction
1. The thyroid gland produces hormones-yodotironiny and hormone calcitonin. Carry thyroxine to the first class of hormones and triyodtironin. At the same time the majority of synthesizable thyroxine will be transformed in triyodtironin because it better is perceived by receptors.
2. Yodotironina influence functional activity of an organism, practically all bodies and systems. Receptors of these hormones fasten to DNA threads or are located nearby. At contact of receptors with tireoidny hormone, processes of formation of intracellular proteins are started.
3. Tireoidny hormones increase metabolism speed in all organism. Along with it the rate of decay of protein increases. The intensification of brain activity is noted, endocrine glands become more active, there is a process of growth at teenage age more actively.
4. Enough tireoidny hormone in an organism stimulates growth of quantity of mitochondrions in cages, mitochondrions represent similarity of power stations of a cage. It leads to formation of ATP – a source of cellular energy. Tireoidny hormones increase activity of transport of ions through cell membranes.
5. Hormone calcitonin stimulates decrease in level of calcium in blood plasma. It is synthesized so-called by S-cells of a thyroid gland. These cages are rudiments of special glands of fishes, reptiles and birds.
6. Calcitonin represents peptide from 32 amino acids. It begins to be developed actively at intake of calcium in an organism. Calcitonin reaches due effect in two ways, instant and long.
7. The first way consists in sharp decrease in cells of a bone tissue of osteoklast of ability to rassasyvat a bone. It leads to a calcium delay in the bone tissue capable to its exchange. This mechanism promotes fast exchange of the detained and washed away calcium.
8. The second way results in effect through quite long period. It consists in decrease in formation of new osteoklast. It mediates decrease and quantities of bone cells of osteoblasts which function is formation of a bone tissue.
9. Result of decrease of the activity of osteoklast and osteoblasts is very minor change of level of maintenance of ions of calcium in plasma. Two mechanisms of influence of calcitonin are that. Also calcitonin has small impact on management of calcium in renal tubules and intestines.