Short Notes on Lymphatic System
The lymphatic system is part of the immune system. It also maintains fluid balance and plays a role in absorbing fats and fat-soluble nutrients.
Ans: The lymphatic system is part of the immune system. It also maintains fluid balance and plays a role in absorbing fats and fat-soluble nutrients.
The lymphatic or lymph system involves an extensive network of vessels that passes through almost all our tissues to allow for the movement of a fluid called lymph. Lymph circulates through the body in a similar way to blood.
There are about 600 lymph nodes in the body. These nodes swell in response to infection, due to a build-up of lymph fluid, bacteria, or other organisms and immune system cells.
A person with a throat infection, for example, may feel that their “glands” are swollen. Swollen glands can be felt especially under the jaw, in the armpits, or in the groin area. These are, in fact, not glands but lymph nodes.
They should see a doctor if the swelling does not go away if nodes are hard or rubbery and difficult to move if there is a fever, unexplained weight loss, or difficulty breathing or swallowing.
The lymphatic system has three main functions:
- It maintains the balance of fluid between the blood and tissues, known as fluid homeostasis.
- It forms part of the body’s immune system and helps defend against bacteria and other intruders.
- It facilitates the absorption of fats and fat-soluble nutrients in the digestive system. The system has special small vessels called lacteals. These enable it to absorb fats and fat-soluble nutrients from the gut.
They work with the blood capillaries in the folded surface membrane of the small intestine.
The blood capillaries absorb other nutrients directly into the bloodstream.
Anatomy
The lymphatic system consists of lymph vessels, ducts, nodes, and other tissues.
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.
The lymph vessels form a network of branches that reach most of the body’s tissues. 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.
