The muscles in the back of your tongue help you make certain sounds, like the letters k and hard g (like in the word go). Try saying these letters slowly, and you'll feel how the back of your tongue moves against the top of your mouth to create the sounds. The back of your tongue is important for eating as well.
The most common cause is a benign tumor in your pituitary gland, which is located under your brain. This tumor is not cancer. Because of the tumor, your body makes too much growth hormone. Once in a while, tumors in the pancreas, liver, or parts of the brain can cause high levels of growth hormone. That leads to higher levels of another hormone, called insulin-like growth hormone, which causes the symptoms you see.
1 The pituitary, pineal and parathyroid glands are neuroendocrine glands. 2  The thyroid gland is not a neuroendocrine gland, but it contains scattered neuroendocrine cells known as C cells. 3  The adrenal glands are made up of a non-neuroendocrine area called the cortex, and a central neuroendocrine gland called the medulla. Neuroendocrine cells in the digestive system regulate intestinal movements and the release of digestive enzymes. 2  Neuroendocrine cells in the respiratory system are believed to play a role in the developmental stages of the respiratory organs. 3  They also regulate respiratory function.