PDF | On Jun 16, , Mahmoud Al-Azab and others published Anatomy of the Immune & Lymphatic System. The lymphatic system includes a series of nodes, ducts, and vessels that works closely with the circulatory system and supports the body's defenses. Functions of The Lymphatic System. • Lymphatic capillaries reabsorb excessive tissue fluid and transport the fluid through the lymphatic pathway, and ultimately.

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Lymphatic System Pdf

The Lymphatic System. • network of tissues, organs and vessels that help to maintain the body's fluid balance & protect it from pathogens. • lymphatic vessels . Lymphoma is a cancer of the lymphatic system. The lymphatic system is part of your immune system, which helps protect you from infection. It is spread. Lymphatic System. – M ade up of: • Lymph. • Lymph vessels. • Lymphocytes. • Lymph nodules. • Lymph nodes. • Tonsils. • Spleen. • Thymus Gland. • Red Bone .

Chapter The Lymphatic and Immune System The lymphatic system, for most people, is associated with the immune system to such a degree that the two systems are virtually indistinguishable. The lymphatic system is the system of vessels, cells, and organs that carries excess fluids to the bloodstream and filters pathogens from the blood. The swelling of lymph nodes during an infection and the transport of lymphocytes via the lymphatic vessels are but two examples of the many connections between these critical organ systems. Functions of the Lymphatic System A major function of the lymphatic system is to drain body fluids and return them to the bloodstream. Blood pressure causes leakage of fluid from the capillaries, resulting in the accumulation of fluid in the interstitial space—that is, spaces between individual cells in the tissues. In humans, 20 liters of plasma is released into the interstitial space of the tissues each day due to capillary filtration. Once this filtrate is out of the bloodstream and in the tissue spaces, it is referred to as interstitial fluid. Of this, 17 liters is reabsorbed directly by the blood vessels. But what happens to the remaining three liters? This is where the lymphatic system comes into play.

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. 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.

Contractile Physiology of Lymphatics

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. These finger-like protruding structures are produced by the tiny folds in the absorptive surface of the gut. Lacteals absorb fats and fat-soluble vitamins to form a milky white fluid called chyle. This fluid contains lymph and emulsified fats, or free fatty acids. It delivers nutrients indirectly when it reaches the venous blood circulation. Blood capillaries take up other nutrients directly.

The third function is to defend the body against unwanted organisms.

Functions of the Lymphatic System

Without it, we would die very soon from an infection. Our bodies are constantly exposed to potentially hazardous micro-organisms, such as infections. However, pathogens often do succeed in entering the body despite these defenses. In this case, the lymphatic system enables our immune system to respond appropriately. If the immune system is not able to fight off these micro-organisms, or pathogens, they can be harmful and even fatal.

A number of different immune cells and special molecules work together to fight off the unwanted pathogens.

Introduction to the Lymphatic System | SpringerLink

The lymphatic system produces white blood cells, known as lymphocytes. There are two types of lymphocyte, T cells and B cells. They both travel through the lymphatic system. As they reach the lymph nodes, they are filtered and become activated by contact with viruses, bacteria, foreign particles, and so on in the lymph fluid.

From this stage, the pathogens, or invaders, are known as antigens. As the lymphocytes become activated, they form antibodies and start to defend the body.

This has greatly advanced our understanding of the developmental and remodeling processes that govern some of the structural considerations of the lymphatic system, particularly those in the initial lymphatic vessels where lymph is formed. Much less recent effort has been placed into the study of the lymphatic structures at any level beyond the most peripheral parts of the lymphatic network.

An understanding of the structure and function of the lymphatic architecture must go hand in hand if we are to develop a true appreciation of the impact of the lymphatic system in health and disease.

When evaluating the lymphatic system it is crucial to remember that its principal purpose is the transport of lymph and it is by this regulated transport that ALL of the body's homeostatic functions that the lymphatic system participates in are served.

Lastly but importantly, lymph transport includes not only the initial formation of lymph in the lymphatic capillaries but also the movement of lymph along the rest of the lymphatic network on its route to the veins. Hydrodynamics of Lymph Transport Under steady states, most interstitial fluid pressures are either near atmospheric i. There are many more measures of pressures in the immediate downstream components of the lymphatic vascular network, the early lymphatic collecting vessels.

However, in most instances the pressures measured in these vessels are on average slightly positive. So how does fluid enter the initial lymphatic structure to form lymph? There have been a few theories that have come about over the years to account for this process, but the data to support most of these theories have not been strong.

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 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. Fast facts about the lymphatic system The lymphatic system plays a key role in the immune system, fluid balance, and absorption of fats and fat-soluble nutrients. As lymph vessels drain fluid from body tissues, this enables foreign material to be delivered to the lymph nodes for assessment by immune system cells.

The lymph nodes swell in response to infection, due to a build-up of lymph fluid, bacteria, or other organisms and immune system cells.

Lymph nodes can also become infected, in a condition known as lymphadenitis. If lymph nodes remain swollen, if they are hard and rubbery, and if there are other symptoms, you should see a doctor. Definition Lymph nodes, or "glands" may swell as the body responds to a threat.

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 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.

What does the lymphatic system do?

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. What do the tonsils do? 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. What is the spleen? 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 The thymus gland is a lymphatic organ and an endocrine gland that is found just behind the sternum.

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