Tongue is the organ of human body to taste food, and the feeling of tongue is called "taste", which is in human mouth. In traditional Chinese medicine, tongue is also called spiritual root and mind. The tip of the tongue is called the tip of the tongue, the middle is called the tongue, the root is called the tongue, and both sides are called the lingual side.
There is a V-shaped groove at the top of the tongue, called the boundary groove, which divides the tongue into the front 2/3 of the tongue body and the back 1/3 of the tongue base. The front of the tongue is called the tip of the tongue. There is a mucosal fold in the middle of the sublingual part, which is called lingual frenulum. There are a pair of small protrusions on both sides of the root of lingual frenulum, which are called hypoglossal caruncle. At the top of the caruncle, there are the same openings of submandibular gland duct and sublingual gland duct. The mucosal protuberance extending from the hypoglossal nerve caruncle to the posterolateral side is called hypoglossal nerve fold, and the sublingual gland is hidden on the deep surface of this fold.