What makes the lymphatic system

The lymphatic system also impacts diseases such as excessive obesity caused by abnormal fat and carbohydrate metabolism. The lymphatic system is a network of very small tubes or vessels that drain lymph fluid from all over the body.

The major parts of the lymph tissue are located in the bone marrow, spleen, thymus gland, lymph nodes, and the tonsils. The heart, lungs, intestines, liver, and skin also contain lymphatic tissue. One of the major lymphatic vessels is the thoracic duct, which begins near the lower part of the spine and collects lymph from the pelvis, abdomen, and lower chest.

The thoracic duct runs up through the chest and empties into the blood through a large vein near the left side of the neck. The right lymphatic duct is the other major lymphatic vessel and collects lymph from the right side of the neck, chest, and arm, and empties into a large vein near the right side of the neck. Lymph nodes are round or kidney-shaped, and can be up to 1 inch in diameter. Most of the lymph nodes are found in clusters in the neck, armpit, and groin area.

Nodes are also located along the lymphatic pathways in the chest, abdomen, and pelvis, where they filter the blood. Inside the lymph nodes, lymphocytes called T-cells and B-cells help the body fight infection. Lymphatic tissue is also scattered throughout the body in different major organs and in and around the gastrointestinal tract.

Lymph fluid drains into lymph capillaries, which are tiny vessels. The fluid is then pushed along when a person breathes or the muscles contract. The lymph capillaries are very thin, and they have many tiny openings that allow gases, water, and nutrients to pass through to the surrounding cells, nourishing them and taking away waste products.

The microscopic lymph capillaries merge to form lymphatic vessels. Small lymphatic vessels join to form larger tributaries, called lymphatic trunks , which drain large regions.

Lymphatic trunks merge until the lymph enters the two lymphatic ducts. The right lymphatic duct drains lymph from the upper right quadrant of the body.

The thoracic duct drains all the rest. Like veins , the lymphatic tributaries have thin walls and have valves to prevent backflow of blood. There is no pump in the lymphatic system like the heart in the cardiovascular system.

Around 2 liters of fluid leak from the cardiovascular system into body tissues every day. The lymphatic system is a network of vessels that collect these fluids, or lymph. Lymph is a clear fluid that is derived from blood plasma. They work in a similar way to the blood vessels. The lymph vessels work with the veins to return fluid from the tissues. Unlike blood, the lymphatic fluid is not pumped but squeezed through the vessels when we use our muscles.

The properties of the lymph vessel walls and the valves help control the movement of lymph. However, like veins, lymphatic vessels have valves inside them to stop fluid from flowing back in the wrong direction.

Lymph is drained progressively towards larger vessels until it reaches the two main channels, the lymphatic ducts in our trunk. From there, the filtered lymph fluid returns to the blood in the veins.

The vessels branch through junctions called lymph nodes. These are often referred to as glands, but they are not true glands as they do not form part of the endocrine system.

In the lymph nodes, immune cells assess for foreign material, such as bacteria, viruses, or fungus. Lymph nodes are not the only lymphatic tissues in the body. The tonsils, spleen, and thymus gland are also lymphatic tissues.

In the back of the mouth, there are tonsils. These produce lymphocytes, a type of white blood cell, and antibodies. They have a strategic position, hanging down from a ring forming the junction between the mouth and pharynx.

This enables them to protect against inhaled and swallowed foreign bodies. The tonsils are the tissues affected by tonsillitis. The spleen is not connected to the lymphatic system in the same way as lymph nodes, but it is lymphoid tissue. This means it plays a role in the production of white blood cells that form part of the immune system. Its other major role is to filter the blood to remove microbes and old and damaged red blood cells and platelets. The thymus gland is a lymphatic organ and an endocrine gland that is found just behind the sternum.

It secretes hormones and is crucial in the production, maturation, and differentiation of immune T cells. Bone marrow is not lymphatic tissue, but it can be considered part of the lymphatic system because it is here that the B cell lymphocytes of the immune system mature. During gestation, the liver of a fetus is regarded as part of the lymphatic system as it plays a role in lymphocyte development. Explore the model using your mouse pad or touchscreen to understand more about the lymphatic system.

The lymph system has three main functions. The lymphatic system helps maintain fluid balance. It returns excess fluid and proteins from the tissues that cannot be returned through the blood vessels.

The fluid is found in tissue spaces and cavities, in the tiny spaces surrounding cells, known as the interstitial spaces. These are reached by the smallest blood and lymph capillaries. Around 90 percent of the plasma that reaches tissues from the arterial blood capillaries is returned by the venous capillaries and back along veins.

The remaining 10 percent is drained back by the lymphatics. Each day, around liters is returned. This fluid includes proteins that are too large to be transported via the blood vessels. Loss of the lymphatic system would be fatal within a day. Without the lymphatic system draining excess fluid, our tissues would swell, blood volume would be lost and pressure would increase.

Most of the fats absorbed from the gastrointestinal tract are taken up in a part of the gut membrane in the small intestine that is specially adapted by the lymphatic system. The lymphatic system has tiny lacteals in this part of the intestine that form part of the villi.