Lymph Node Structure, Location, Function, Types

Lymph Node: Structure, Location, Function, Types, and Diseases

A lymph node is an important part of your immune system. It blocks the attack of the foreign bacteria or virus and keeps you healthy. The nodes or glands are spread throughout the body. It is located in groups in a particular part of your body. Each group of lymph glands can drain specific regions of your body. But, like the other parts of the body, it can get affected by diseases. Different problems like infections, trauma or cancer can affect its function. Read ahead to get a comprehensive idea about the nodes, its roles in daily life, and how it keeps you safe from diseases.

Structure Of Lymph Node

The lymph node has a bean-like shape. The glands are located in your lymphatic system. The nodes are enclosed within connective tissue. The internal region of the node is divided into compartments referred to as nodules. It contains the B and T-cell lymphocytes. The central area of the lymph node known as medulla contains the macrophages (the infection-fighting white blood cells). Therefore, when you see an enlarged lymph node, it indicates the presence of infection. The multiplication of the B and T cell lymphocytes point towards infection.

The nodes have different sizes and vary from a few millimeters to two centimeters in diameter. You can find the nodes near the junction of major lymphatic vessels. So, it is more concentrated on regions like neck, groin, and armpits. The lymphatic glands are also known as secondary lymphoid organs. Hundreds of lymph nodes in your body help prevent the attack of virus and bacteria attack.

Function Of Lymph Node

The lymph node acts like a filter, which keeps away the viruses, bacteria, parasites, and other foreign material. The lymphatic vessels can bring these elements into your nodes. So, the lymph glands can keep them away from your bloodstream. It even filters the cancer cells. That is the reason why doctors check the lymph nodes in patients suspected of cancer. It is the first place that catches the cancer cells before they find another place in your body. Therefore, a cancer diagnosis is possible by evaluating the lymph glands.


Your lymph glands are also responsible for fighting infections in your body. It traps the virus or bacteria in the nodes and allows the T cells to fight against it. While the B cells create antibodies against the specific invader. So, your body can remain safe from the attack on the particular invader in the future. The lymph node acts as the place that helps in the communication of immune cells. It aids in the immune cells to work together to protect your body.

Types And Locations Of Lymph Node

You may know about the nodes when you have a throat infection. Your doctor checks for the swollen glands to detect the extent of your cold or sore throat. But, unlike the popular perception, you can find the nodes is not just the neck but also in different parts of your body. Some nodes lie near the surface of your skin. Therefore, you can feel the nodes in areas like the back of your knee, elbow, groin, armpit, and neck when they enlarge. The other lymph glands reside deep inside your body, which you can see only with sophisticated imaging techniques. Therefore, the important nodes and their locations are:

Cervical Lymph Gland

The node lies in your neck. You can feel it when you suffer from respiratory tract infection. The main function of the node is to filter the lymphatic fluid from your scalp, head, and neck region. The nodes in your neck are divided into three regions. So, depending on the region of presence, the lymph gland offers vital information to your doctor while diagnosing an illness. The three different nodes are:

Anterior Cervical Lymph Node

It is the gland that you can find in front of your neck. You can feel the gland when you suffer from strep throat or a common cold. It can swell during such infections and make its presence known.

Posterior Cervical Lymph Gland

It runs on the lateral side of your neck. You can locate it behind the band of muscles on the posterior nodes. It is commonly is felt when you get affected by infectious mononucleosis. So, the enlargement caused due to the contraction of mono can reveal its presence.

Occipital Lymph Node

The nodes are located at the back of your neck. It lies exactly at the base of your skull. You can know its presence when you get swelling due to mono.

Apart from the above-mentioned nodes, you can also find the lymph glands in front and behind your ear. It is also spread along your jawline.

Axillary Lymph Node

The lymph glands are located in your armpit. You can find twenty to forty lymph nodes in your armpit. Breast cancer and other diseases can swell the gland and make it large. Therefore, a patient detected with breast cancer undergoes axillary node dissection. So, the removal of the nodes can prevent cancer from spreading. It is the most important node that can help your doctors find a cancerous presence in your body.

Your lymph node that collects the lymphatic fluid, which picks up the cancerous cells. It is the very first node affected by the cancer cells. So, your doctor suggests a sentinel node biopsy along with the breast cancer to detect the cancerous presence. It eliminates the need to remove all the nodes as only the affected node needs abstraction. Therefore, a tracer injected into cancer can reveal the nodes it travels. Only the first few nodes, it travels get biopsied.

Supraclavicular Lymph Node

These are the nodes you can find above the collarbone. You can feel it above your clavicle or collarbone when it enlarges. The swelling of the nodes indicates a serious health problem that needs immediate medical attention. So, see your doctor as it swells only during lymphoma or lung cancer.

Mediastinal Lymph Node

The partition area between your lungs, at the center of the chest, is known as the mediastinum. The mediastinal lymph nodes reside at the specific area. Unlike the other nodes mentioned above, you cannot see the glands in the area. It is only visible on the images obtained by the sophisticated imaging techniques like CT scan or PET scan. It is important for determining the staging of lung cancer and other lymphomas. The cancerous cell presence in the nodes can help your doctor with the staging of cancer.

Inguinal Lymph Node

It refers to the lymph gland present in your groin region. The main function of the node is to drain the tissues from your feet to your groin region. Therefore, it is susceptible to inflammation due to several reasons. Any infection or injury to the legs can cause inflammation. You can also experience swelling due to the STD (sexually transmitted disease) or cancer. In most cases, the enlarging of the nodes may indicate no problem. It can occur due to the catching of virus or bacteria by the node. Even a small sore on your leg can cause the invasion of foreign entities. So, the gland tries to prevent further problem by catching it. It results in the swelling in your groin region.

Retroperitoneal Lymph Node

It is located deep in your abdomen area. You can only see the nodes using a sophisticated imaging technique. It is due to the fact that it lies on the specific abdominal cavity closer to your backbone. So, the nodes lie immediately behind your intestine and are farther from your belly button. It is significant in identifying testicular cancer in men. Therefore, a doctor first checks the nodes to confirm if a patient has a cancerous presence in their testis or not.

Mesenteric Lymph Node

The nodes like the retroperitoneal nodes lie deep inside your abdomen. It is located in the membranes that surround your intestine. In adolescents and young children, the nodes can become inflamed. So, it enlarges the nodes lying in the membrane, which attaches your intestine to the abdomen. The swelling is referred to as mesenteric lymphadenitis. The signs and symptoms often mimic appendicitis. Therefore, careful analyses can only distinguish the problem. Though cancers can also enlarge the nodes, the occurrences are rare. The hundreds of lymph nodes available in the region help fight the disease. It traps the invaders like bacteria and virus that affect your gut health.

Pelvic Lymph Node

As the name suggests, you can find the nodes deep inside the pelvic region. It lies along the internal, external as well as the common iliac arteries. Iliac arteries are the blood vessels, which supplies blood to the trunk and lower abdomen of your body. When the lymphatic fluid from the bladder, prostate or other area has cancerous cells, it can swell. Your doctor can see the enlarged pelvic lymph nodes using imaging studies.

Other Lymph Nodes

Apart from the different types of lymph glands discussed above, you also have other nodes. You can find lymph node in regions like behind the knee, near the elbow, on your airways, the paraaortic (aorta), and other areas of the body.

Diseases Affecting The Lymph Node

Your lymph node can get affected by different conditions. It can lead to the abnormal size of the lymph node. The term lymphadenopathy refers to the abnormal lymph node that has an abnormal shape, size or even number. When you have localized lymphadenopathy, only nodes in one area suffer the effects. The lymph glands can suffer from the following problem leading to lymphadenopathy.

Inflammation

The lymph gland can suffer inflammation due to various conditions. The immunologic and inflammatory causes of the lymph gland are:

Lupus

Lupus is the autoimmune disease that can trigger your immune system to react, leading to injury or inflammation of body tissues including lymph glands. The misdirected immune system can affect several parts of the body. The condition has no complete cure. So, you can only take steps to control the symptoms. The health problem can trigger painless swelling of your body parts.

Rheumatoid Arthritis

The autoimmune disease can trigger chronic inflammation, especially of your joints and other areas of the body. People suffering from rheumatoid arthritis can have painless, movable, non-tender, and discrete lymph glands. The size of the node may vary from small size to sizable nodes.

Infections

Lymphadenitis is the condition occurring due to the infections in your lymph nodes. The infection can occur due to viral, bacterial, or fungal infections. The lymph gland becomes infected due to the problem in other parts of your body. It spreads to the lymph node and makes it tender.

Viral Infections

It is the most common cause of infection of your lymph gland. Among the different factors, upper respiratory infections occur commonly. So, problems like a common cold can cause infection of your lymph glands. It mostly affects the nodes in your neck region and causes swelling. In most cases, the viral infection can cause the nodes to swell 0.5 inches to 1 inch across. The slight swelling along with mild tenderness suggests your nodes have the capability to fight the infection successfully. The common viruses triggering the problem are:

Bacterial Infections

Cat Scratch Disease

Bacteria can invade affect other parts of the body. When the infection spreads to the lymph glands it can cause swelling. The swelling that has the size of more than one inch across with slight tenderness, it means your body is fighting the problem. But, the size of more than two inches across with pink colored skin means your body is finding it difficult to control the infection. The nodes may also contain pus. So, the different bacteria that can trigger the swelling of the lymph glands are:

Parasites

Parasites can invade humans and infect them with parasitic diseases. The parasites, including worms and various protozoa can either cause infection inside the body or trigger infection within the skin superficially. Therefore, common types of diseases caused by parasites resulting in swelling of your lymph glands are:

  • Toxoplasmosis

The infection occurs due to the protozoan with a single cell referred to as Toxoplasma gondii. In most people, it triggers no symptoms. But, it can lead to swollen lymph glands. You can also experience other signs like ill feeling, fever, blurred vision or sore throat due to the parasitic infection. It can affect people who have a weakened immune system. In people suffering from AIDS, the parasitic infection can reactivate and cause severe brain damage.

  • Leishmaniasis

It is the disease caused by the parasites that come under Leishmania type. The bites from certain kinds of sandflies can result in the problem. It results in other signs along with the enlarging of the lymph glands.

Fungus

The fungus can trigger an infection in your body. Coccidioidomycosis is the most common type of fungal infection resulting in the swollen lymph glands. The problem occurs when you inhale the seeds or spores of Coccidioides posadasii or Coccidioides immitis fungi. It can cause infection in your body, resulting in the infection of the lymph glands. You may wonder the fungi can reach your body. The fungi triggering the problem remain in the soil of certain areas known as endemic. When the geographic area is disturbed, the fungi get into the air. So, you inhale the fungi, which reaches your body and causes infection.

Cancer

Cancer is another main disease affecting the lymph node. You can classify it into two types:

Cancer Originating in the lymph gland

Cancerous cells can originate in the lymph gland and result in swelling. It can occur in the node itself or affect the blood cells. The common examples are lymphomas. Leukemia and its types can also affect the nodes.

Metastatic cancer

Cancer can spread from the other organ in your body (metastasis) and affect the lymph node. It occurs when the cancer cells break away from the tumor. Then, it reaches the other areas of the body through your blood or through the lymphatic system. Cancer that opts for blood to travel reaches other organs and affects them. While the cancerous cells that opt the lymph system to travel ends in the lymph glands. For example, lung cancer affects the lymph glands around the collarbone while breast cancer affects the axilla nodes (underarm).

Injuries And Trauma

The lymph glands are responsible for the cleaning of the site that suffers any injury or trauma. The white blood cells remain at the specific site of injury to ensure the problem does not escalate. It prevents any other infection or inflammation due to the injury or trauma suffered. Therefore, it results in the swelling of the nodes near the injured region.

Conclusion

The lymph node is vital in identifying some serious condition early to avoid complications. People often consider the glands as some bad news. Most of the times, the swelling in the glands needs treatment, which makes people skeptical. But, remember the nodes perform an important job in fighting off diseases by the external invaders. The nodes can catch cancer even when they have solid tumors. It can prevent cancerous cells from traveling deep into your body. Therefore, if you encounter swelling in the lymph glands get medical care as soon as possible as it may indicate a serious problem.

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