An ocean trench is a geological structure which occurs undersea along the boundary of a tectonic plate.Specifically, ocean trenches form along subduction zones, in areas where one plate is being sucked under another.The largest of these trenches are in the Pacific Ocean, where numerous active subduction zones have been identified, but smaller trenches can also be seen in the Indian and Atlantic Ocean.he deepest ocean trench is the Mariana Trench, in the Western Pacific Ocean. Numerous other trenches criss-cross the Pacific, and appear along the edge of South America.
If your blood test shows low TSH levels, you may have a common condition called hyperthyroidism, which is when your thyroid gland produces too much T3 and T4. Low levels of T3 and/or T4, however, can indicate a condition called hypothyroidism.t secretes thyroid hormones T3 and T4. These hormones help regulate your metabolism. The pituitary gland, located at the base of your brain, produces thyroid-stimulating hormones (TSH) that tell your thyroid gland to produce T3 and T4.
Hypothyroidism (Underactive Thyroid) Part 1: Too Little Thyroid Hormone. Hypothyroidism is a condition in which the body lacks sufficient thyroid hormone. Since the main purpose of thyroid hormone is to run the body's metabolism, it is understandable that people with this condition will have symptoms associated with a slow metabolism. The estimates vary, but approximately 10 million Americans have this common medical condition.