Under the normal tongue there are glands, ducts, nerves, and accompanying arteries and veins. 1. Glands. Underneath the normal tongue are the sublingual glands and the deep part of the submandibular gland, whose main function is to secrete saliva. 2. Ducts and nerves. Located on the medial side of the sublingual gland, there is a duct of the submandibular gland traveling from posterior to anterior to superior, opening in the mouth to the sublingual caruncle. The lingual nerve crosses the duct of the submandibular gland toward the tongue. 3. The hypoglossal nerve and accompanying veins. The hypoglossal nerve sends out branches to the muscles outside the tongue. Near the hypoglossal nerve, there is a vein accompanying the hypoglossal nerve. 4. Sublingual artery. It is one of the terminal branches of the lingual artery, traveling between the sublingual gland and the sublingual muscles, and giving off branches to the lingual ligament. There is a lot of content under the tongue, and when it is injured, it is necessary to consult the doctor in time, pay attention to compression to stop bleeding, and avoid the swelling that causes asphyxiation.