How is Lymph Formed and Transported - Flowchart of Lymphatic Circulation » AnatomyLearner >> The place to learn veterinary anatomy online (2023)

Lymph is a clear, colorless liquid found in the lymph capillaries, vessels, trunk, ducts, and sinuses of the lymph nodes. Its composition is similar to plasma (with minor differences) and returns to normal blood circulation through the cranial vena cava.

But how is lymph formed and transported into the normal bloodstream? If you have these specific questions about lymph formation, then this article may help you get a brief answer.

Quick answer: Lymph is formed when plasma seeps through the small pores of the blood capillaries into the interstitial tissue. A series of lymphatic vessels collected lymph from the tissue space and drained it through the right and left (thoracic duct) lymphatic ducts into the cranial vena cava.

But, if you want to know the details of the formation of lymph in the tissue space and its transport to the right atrium of the heart, then let us continue this article to the end. Here I try to explain why lymph arises in the tissue space and how it is transported through the lymphatic vessels.

Okay, let's move on to the main part (lymph) of the article to learn the basics of lymph formation and transport.

How is lymph formed?

I hope you have a basic concept of the general blood circulation in the animal body. In general, oxygen-rich blood is transported to the various parts of an animal's body through the aorta (with its various branches).

In various tissues or organs, it deprives oxygen and enters carbon dioxide; thus oxygen-poor blood is formed. The oxygen-poor blood is now transported through the cranial and caudal vena cava into the right atrium of the heart.

Here, too, the oxygen-poor blood is transported through the pulmonary artery to the lungs, where it is cleaned. In this way, the oxygen-enriched blood returns to the left atrium of the animal's heart.

If you want to know the details of this general systemic blood circulation, you can read the recommended article mentioned below –

What is the difference between pulmonary and general systemic blood flow,

Based on the general blood circulation in the animal's body, you can easily understand that the blood circulation pressure in the arteries and capillaries is higher than in the veins. Again, in the structure of each capillary, you will typically find the pore in its wall.

These pores are normal in the structure of a blood vessel (arteries and capillaries). It is through these pores that the nitrogenous products produced by the interstitial cells enter the blood vessels. Here, too, cells in the tissue receive their nutrients through diffusion from the blood cells.

Factors affecting the formation of lymph in the tissue space

There are two main factors affecting lymph formation in the tissue space –

• The additional pressure in the blood capillaries and
• pores in the structure of blood capillaries,

Now let's look at how lymph is formed in the tissue space. And how these 2 factors are involved in the formation of lymph in the body tissues of an animal.

The excess pressure on the blood vessels (capillaries) causes plasma to seep through the pores in the wall. Because the diameter of the red blood cells is larger, they cannot pass through these pores in the blood vessel wall.

Only the white blood cells of the blood come out of the pores of the vessel wall. Because there are no red blood cells, this leaking fluid looks white and is stored in tissue space.

This clear (white) fluid is the lymph in the tissue space (see figure). You know that circulation is a continuous process, therefore lymph formation continues. As a result, white-colored fluid (lymph) accumulates in the tissue space.

These clear tissue fluids must be removed from the tissue space. Otherwise, they lead to swelling of certain body parts (tissues) of the animal.

But this condition does not usually occur; The animal's body has a different set of vascular channels that remove this excess fluid (lymph). These additional vascular channels of the animal's body are the lymphatics (capillaries and vessels).

I hope you got the answer to your question - how is lymph formed in tissue space? Let's see how these lymph vessels remove lymph (Limf) from the tissue spaces.

How is lymph moved through lymphatic vessels?

First, let's look at the structure of the additional set of the vascular canal, which removes the lymph from the tissue space. These lymphatic vessels (capillaries) are the blind end structure found in the interstitial tissue.

So how does this lymph get into these lymph vessels? These lymph vessels (capillaries) have simple squamous cells that overlap (see illustration).

The pressure of the excess fluid (lymph) in the interstitial tissue squeezes these lymphatic capillary cells. In this way a path is created and lymph will enter through these passes.

The lymph capillaries have valves like the veins. There is no reflux of the lymph within the lymphatic vessels. Normally, the lymph goes in one direction because it pushes excess fluid.

Now the lymph capillaries connect to the lymph vessels. These lymph vessels also connect to form another lymph trunk. Eventually, the various lymphatic trunks of the animal's body unite to form the lymphatic system.

But when the lymph goes from the capillaries to the vessels, you can see different lymph nodes in their passages. Lymph passes through the sinuses of the lymph node at least once before entering the body's venous system.

There are 2 lymphatics in the animal's body - right and left lymphatics. The left lymphatic duct, which is larger than the right lymphatic duct, is referred to as the ductus thoracicus.

The length of the right lymphatic vessel is so small and it empties into the right common jugular vein (sometimes into the right subclavian vein). At the same time, the left lymph node (ductus thoracicus) also empties into the right common jugular vein (sometimes the left clavicle vein).

Finally, the lymph from the right and left common jugular veins is drained into the cranial vena cava and enters the general circulatory system.

How do lymph nodes filter the lymph?

As you saw in the previous discussion, lymph can easily enter the blind end capillaries of the lymphatic system. But not only lymph enters the lymphatic capillaries, some tissue debris and other particles can also enter the lymphatic capillaries if the space is larger.

Suppose the specific tissue has an infection or foreign material or bacteria. Then these foreign objects, bacteria and tissue debris pass through the capillaries of the lymphatic system.

So if filtration doesn't take place, all of these drugs could be transported to the right atrium of the heart. Eventually they enter the general systemic circulation and spread throughout the animal's body.

However, this condition does not usually occur because the animal's body has a different defense mechanism. In the course of the lymphatic vessels (capillaries and vessels) there are various lymph nodes.

You know, in the lymph node you will find the accumulation of lymphocytes (nodules). When the foreign bodies travel with the lymph into the sinuses of the lymph nodes, more white blood cells, or lymphocytes, accumulate.

They identify these foreign objects and try to fight them. More foreign bodies or bacteria or other agents lead to more production or accumulation of lymphocytes, or white blood cells, in the lymph node.

So as more infections occur, the animal's lymph nodes swell because more lymphocytes accumulate. These swollen lymph nodes in the animals indicate the infection in their body.

What are the right and left lymphatic ducts?

These are the main vessels that collect lymph from different areas of the body. The right lymphatic duct of the lymphatic system collects lymph from the right head, neck, right thorax, and right front leg of the animals.

The left lymphatic or thoracic duct collects lymph from a wide area. It collects lymph from the left thorax, left arm, left neck, head (smaller), left and right hind legs, and abdominal cavity (cisterna chyli).

The lymph collection point for the thoracic duct is therefore wide compared to the right lymphatic duct. But how does this left lymphatic or thoracic duct develop? To know the formation of the thoracic duct, you may first know about the cisterna chyli.

What is a Chyl tanker?

These are the elongated and expanded sacs that act as lymphatic reservoirs. Typically, this cisterna chyli is formed by the union of lumbar and gastrointestinal lymphatic trunks.

The cisterna chyli is located to the right of the abdominal aorta at the velum of the second or third lumbar vertebra. You will find a close relationship of the cisterna chyli with the right side of the diaphragmatic crus.

The thoracic duct (left lymphatic duct) begins at the cranial end of the cisterna chyli.

Where are the lymph vessels missing?

In certain body regions of the animal you will not find any lymphatic vessels. Let's see which organs and areas do not have lymphatic vessels –

• Bone marrow and central nervous system of the animal body (except meninges),
• umbilical cord and embryonic membrane,
• hyaline cartilage of any structure,
• The epithelial layer of the skin,
• cornea, lens and vitreous body of the animal eye,

Functions of the lymph or the lymphatic system

If you consider how lymph is formed and transported through the lymphatic vessels into the blood (general circulation) you will find the following 2 important functions –

• The lymphatic system or vessels remove or remove the excess fluid (lymph or limf) from the interstitial tissue space,
• It carries out a defense mechanism in different ways,

When microorganisms enter through the lymphatic vessels, they are destroyed by the lymphocytes present in the lymph node. Thus, the lymph node filtered the microorganism from the lymph and protected the animal's body.

These are 2 main functions of the lymphatic system or lymph in the animal's body. In addition, the lymph and the lymphatic system also possess the functions mentioned below –

This system of the animal's body balances fluid - tissue fluid (lymph) is drained through the lymphatic vessels into the bloodstream,

Aid in the absorption of fat from the digestive tract and enters the venous circulation via the lymphatic vessels,

I hope you can understand the primary function of the lymph and the lymphatic system in the animal's body.

Flow chart of the lymphatic circulation

See how is lymph formed and transported into the general bloodstream? Well, it will be better if I provide a flow chart of the lymphatic circulation, which is the summary of everything (formation and transport).

Here, in the Lymph Circulation Flow Chart, I have tried to depict the issues mentioned below –

• Normal blood flow and plasma leakage from the blood capillaries,
• formation of lymph in the tissue spaces,
• Formation of a new set of lymphatic capillaries (lymphatic system),
• capillaries connect from the lymphatic vessels,
• Lymph nodes in the lymphatic system (filter lymph),
• Lymph vessels join to form the lymphatic trunks,
• Formation of the lymphatic system – right and left lymphatic system and
• Directs lymph from the right and left lymph ducts into the cranial vena cava,

So, the flow chart of the lymphatic circulation represents the summary of the lymphatic system. It is enough to understand the basics of the lymph, the lymphatic vessels and the lymphatic circulation in the body of the animal.

How is lymph made and transported labeled diagram

Now the labeled diagram is also intended to show the formation and transport of the lymph through the lymphatic vessels and finally the outflow into the right atrium of the heart. If you follow my previous discussion on lymph formation and transport, you will easily understand the labeled diagram mentioned below.

In this diagram I have tried to show the different structures of the lymphatic system such as the lymph, the lymphatic vessels (capillaries, vessels, trunks and ducts) and the lymph nodes. Here I have drawn different lymph vessels from the different body regions of the animals.

Various lymphatic trunks such as tracheal, hepatic, gastric, lumbar, celiac, intestinal, jejunal, colic and visceral trunks are also shown in the labeled diagram (some are overlooked). Again, the labeled diagram shows 2 main ducts (right and left lymphatic duct) from the animal's lymphatic system.

Finally, in the labeled diagram, you can see the enlarged and elongated sac-like cisterna chyli. You can find more diagrams of the animals' lymphatic system here.

Further inquiries about lymph formation

Now let's look at some of the most common inquiries about the lymph and the animal's lymphatic system. Here I am going to list some of these important questions about lymph that are being asked by anatomy students. Let's look at these studies on the lymphatic system or lymph or lymph vessels.

What is the lymphatic system and the lymphatic system?

In its broadest sense, the lymphatic system is a description and functional aspect of the lymphoid tissue. Lymphatic tissue includes the lymphatic vessels (lymphatic vessels), organs and cells.

The lymphatic vessels of the lymphatic system include –

The lymph capillaries and vessels,

lymph trunks and ducts,

Additionally, in the animal’s lymphatic system, you will find 2 types of lymphoid organs –

Primary Lymphatic Organs – include bone marrow and thymus and

Secondary or peripheral lymphoid organs - includes the spleen, lymph nodes, tonsils and Payer's patches of the ileum,

In the lymphoid cells of the lymphatic system you will find the following cells –

T lymphocytes, B lymphocytes, macrophages and natural killer cells,

But what does the lymphatic vasculature mean? The lymphatic system includes capillaries, vessels, trunks and ducts. The lymph nodes or other organs are not included in the lymphatic system.

How is lymph formed short answer?

Lymph is formed in the tissue interstices when the plasma escapes from the pores in the blood vessel wall. This leakage or leaking of plasma occurs due to the overpressure on the blood capillaries and vessels.

So the accumulation of leaked plasma in the tissue space is clear because it does not contain red blood cells. This gives it the white color and is called lymph.

How is lymph different from blood?

You know that lymph is a clear, colorless liquid that resides in the tissue space near the blood vessels. While the blood is reddish, fluid is flowing through the blood vessels (veins and arteries).

The lymph is part of the lymphatic system while the blood is part of the general circulatory system of the animal's body. If you think about the compositional difference between lymph and blood, you will find plasma, red blood cells (RBC), white blood cells and platelets in the blood.

In addition, the lymph contains plasma and few blood platelets. But there are no red blood cells in the composition of the lymph.

The amount of oxygen carried by the blood is greater than that carried by the lymph. A suitable defense mechanism can be found in the lymph in the animal's body. Thus, the lymph is considered part of the immune system of the animal body.

The blood has many functions in the body of the animal. They are associated with the circulation of oxygen and carbon dioxide in body tissues. Again, it is about the circulation of various substances such as waste products.

What is a lymph center and where can you find it?

These lymph nodes or groups of lymph nodes are consistently present in the same area of ​​the animal's body. In all animal species, this lymph center receives the supplying vessels from approximately the same region.

In the body of the animal you will find 7-8 lymphatic centers. Here I show these lymph centers from the animal's body with some of their important superficial lymph nodes -

• Lymphatic center in the head region – includes submaxillary, parotid and retropharyngeal lymph nodes,
• Cervical lymphatic center – includes superficial and deep cervical lymph nodes,
• Lymphatic center in the animal's thorax - includes the axillary lymph nodes,
• Lymphocenter of the thoracic cavity – has the dorsal and ventral thoracic lymph nodes, mediastinal lymph nodes and bronchial lymph nodes,
• Lymphatic center in the abdominal and pelvic walls – has lumbar, sacroiliac, inguinofemoral (superficial inguinal) and sciatic lymph nodes,
• Pelvic Lymphocenter – includes iliofemoral and popliteal lymph nodes and
• Lymphatic center in the abdominal viscera – owns the celiac, cranial and caudal mesenteric lymph nodes,

You know that these lymph centers and their various lymph nodes play a huge role in filtering the lymph as it flows through the vessels and nodes. Swollen lymph nodes in an animal indicate infection, so you may know the location of some of the animals' superficial lymph nodes.

Therefore, palpating these lymph nodes will help you when they become swollen due to insufficient lymph drainage or other problems in the lymph.

Diploma

I hope you answered the question correctly - how is lymph formed and transported into the general bloodstream? Lymph formation begins with the exit of plasma from the blood vessels into the tissue spaces.

The lymphatic capillaries (small) collect the lymph from the interstitial tissue space and transport it through the lymphatic vessels into the lymphatic system. The right and left lymphatic ducts of the lymphatic system drain the filtered lymph (filtered by lymph nodes) through the cranial vena cava into the right atrium of the heart.