Lymphatic Drainage of the Oral and Nasal Cavities
The lymphatic system is an essential network that functions in accordance with the circulatory system in order to shift fluid known as lymph back towards the heart. Lymph nodes or lymph vessels exist all over the body, primarily around the major organs that are supplied by large vessels. They collect the lymph and pass it along the lymphatic capillaries and vessels into the left and right thoracic ducts. This article will highlight the importance of the lymphatic system and its main functions as well as run through the anatomical structure of the lymphatic network that surrounds the oral cavity and nasal cavity. Lastly, the brief overview of the potential pathological disorders in relation to the lymphatic system will be discussed.
The main functions of the lymphatic system include:
- The absorption and transportation of fatty acids as fat and chyle from the digestive tract
- The transportation of old leukocytes from the lymph nodes to the bones
- The transportation of antigen-presenting cells (APC’s) to the lymph nodes in order to trigger an immune response
Lymphatic Drainage of the Nasal Cavity
The external lateral portion of the nose is classed under the lymphatic vessels of the face and drains into the submaxillary nodes. The lymphatic vessels that specifically drain the nasal cavities drain into the nodes based on their placement be it anterior or posterior. The vessels from the anterior third of the nasal cavity follow the vessels of the external nose and end up in the submaxillary nodes. Vessels from the posterior two thirds of the nasal cavity and from the ethmoid sinuses drain partly to the retropharyngeal nodes and partly to the superior deep cervical nodes.
Lymphatic Drainage of the Oral Cavity
The lymphatic drainage of the oral cavity is divided firstly into regional nodes and then into deep cervical nodes. For clarity, it should be noted that only the nodes that directly drain the anatomical structures of the oral cavity will be mentioned and are named after the area they drain. The regional nodes are as follows:
- The parotid nodes sit upon the parotid gland and drain it;
- The buccal nodes sit on the cheek over the buccinator muscle and siphon off the lymph that is collecting in the submandibular nodes;
- The submandibular nodes lie on the lateral wall of the submandibular gland and drain the cheek, the upper lip, the lower lip, the maxillary sinus, the upper and lower teeth, the anterior two thirds of the tongue, the floor of the mouth, the vestibule and the gums;
- The submental nodes are found in the submental triangle below the chin and drain the tip of the tongue, the floor of the anterior part of the mouth, the incisors, the central part of the lower lip and the skin of the chin;
- The superficial cervical nodes lie on the external jugular vein and drain the skin over the angle of the jaw and the skin covering the lower portion of the parotid gland.
The deep cervical nodes are as follows:
- The jugulodigastric node sits posteroinferiorly to the jaw and drains the tonsils and the tongue;
- The jugulo-omohyoid node is found close to the omohyoid muscle and drains the tongue.
Abnormalities in the lymph nodes of the head and neck can help oncologists pinpoint potential tumours in the earliest stages. There are five levels of lymphatic drainage for the head and neck running craniocaudally that each govern primary sites. For example, level one contains the submental and submandibular triangles. If any of these lymph nodes becomes enlarged and cancer is a concern, the primary sites to check would be the lower lip, the chin, the anterior oral cavity and anterior third of the tongue for the submental nodes and the lips, floor of the mouth, tongue and facial skin for the submandibular nodes respectively. The ability to localize a tumor in its earliest stages not only increases the likelihood of a better prognosis, but it reduces the invasiveness of the tumor removal, especially where the head and neck is concerned.