Lymph nodes are small, bean-shaped structures distributed throughout the body, including various locations on the head. They are part of the body’s defense system, acting as filtering stations to protect against infection and illness.
Understanding Lymph Nodes
The lymphatic system is a network of vessels, tissues, and organs that transport a clear fluid called lymph back into the bloodstream. Lymph nodes are specialized glands within this system, shaped like beans and typically measuring about 1 to 2 centimeters in a healthy adult. They filter lymph fluid, which contains waste products, damaged cells, and foreign substances like bacteria and viruses.
Immune cells, such as lymphocytes (a type of white blood cell), reside within the lymph nodes. When lymph fluid flows into a node, these cells identify and eliminate pathogens, preventing their spread. This process is a fundamental part of the body’s immune response, also helping to maintain proper fluid balance.
Key Lymph Node Locations on the Head
The head region contains several groups of lymph nodes, strategically positioned to monitor and filter fluid from specific areas of the face, scalp, and mouth. These nodes are usually small and not easily felt unless they become enlarged due to an immune response. Their locations can help pinpoint the source of an infection or inflammation.
Pre-auricular Lymph Nodes
Located directly in front of the ear, often near the superficial temporal artery, these nodes primarily drain lymph from the superficial areas of the face, the temporal region of the scalp, eyelids, and external ear.
Post-auricular (Mastoid) Lymph Nodes
Found behind the ear on the mastoid bone, these nodes receive lymph from the posterior temporoparietal scalp, the upper ear, and the back of the external ear canal.
Occipital Lymph Nodes
At the back of the head, near the base of the skull and hairline, lie the occipital lymph nodes. They are situated close to the margin of the trapezius muscle and collect lymph from the occipital region of the scalp and the upper neck.
Submandibular Lymph Nodes
Underneath the jawbone, along its lower border, are the submandibular lymph nodes. This group drains a wide range of areas, including the upper and lower lips, cheeks, sides of the nose, gums, most teeth, and parts of the tongue.
Submental Lymph Nodes
Located centrally under the chin, in the submental triangle, are the submental lymph nodes. They collect lymph from the lower lip, the floor and apex of the tongue, the chin, and the lower incisor teeth.
What Causes Lymph Nodes to Swell
Lymph nodes commonly swell when the body is actively fighting an infection or inflammation. This enlargement, medically termed lymphadenopathy, happens because immune cells gather within the nodes to combat pathogens. The swelling indicates that the immune system is engaged and working to clear away harmful substances.
Common causes for swollen lymph nodes on the head include various types of infections. Viral infections such as the common cold, flu, ear infections, and mononucleosis frequently lead to noticeable swelling. Bacterial infections, including strep throat, dental infections, or skin infections on the scalp or face, can also cause localized lymph node enlargement.