Tag Archives: lymphatic system

The Lymphatic System

What Does The Lymphatic System Do?

The lymphatic system has three main purposes:

  1. It removes excess fluid and waste products from the spaces between the cells and returns them to the blood stream.

  2. It aids the immune system in destroying and removing waste, debris, dead blood cells, pathogens, toxins, and cancer cells.

  3. It absorbs fats and fat-soluble vitamins from the digestive system and delivers these nutrients to be used by the cells of the body.

Lymphatic System

What Makes Up The Lymphatic System?

Lymph leaves the area of the cells through lymph capillaries, which merge together into larger lymphatic vessels that carry lymph throughout the body.

5 Interesting Facts About The Lymphatic System

  1. There are over 500 lymph nodes throughout the body, with the majority of them being located in the neck, groin and armpits.

  2. Lymph is a mixture of about 90% water and 10% solutes such as proteins, cellular waste products, dissolved gases, and hormones.

  3. The lymphatic system returns about 3.17 quarts (3 liters) of fluid each day from the tissues to the circulatory system.

  4. One way that lymph moves is via the squeezing action of the skeletal muscles surrounding the lymph vessels.

  5. On average, at any time about I to 2 quarts of lymph fluid circulates in the lymphatics and body tissues.

Since the lymphatic system does not have a heart to pump it, its upward movement depends on the motions of the muscle and joint pumps as well as the movement of the diaphragm when we breathe.

The lymph passes through Lymph nodes, which are round or kidney-shaped, and, while usually smaller, can be up to one 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.

All of the lymphatic vessels of the body carry lymph toward the two lymphatic ducts: The thoracic duct connects the lymphatic vessels of the legs, abdomen, left arm, and the left side of the head, neck, and thorax to the left brachiocephalic vein. The right lymphatic duct connects the lymphatic vessels of the right arm and the right side of the head, neck, and thorax to the right brachiocephalic vein.

Outside of the system of lymphatic vessels and lymph nodes, there are masses of lymphatic tissue known as lymphatic nodules. They work to protect the body from pathogens entering the body through open body cavities. The most prominent of these are Tonsils and Adenoids and Peyer’s Patches. Peyer’s Patches are small masses of lymphatic tissue found in the small intestine. Peyer’s patches contain T and B cells that monitor the contents of the intestinal lumen for pathogens. Once the antigens of a pathogen are detected, the T and B cells spread and prepare the body to fight a possible infection.

The lymph system also includes the spleen, thymus and bone marrow.

The Spleen is a flattened, oval-shaped organ located in the upper left quadrant of the abdomen lateral to the stomach. The spleen contains lymphocytes and another kind of white blood cell called macrophages, which engulf and destroy bacteria, dead tissue, and foreign matter and remove them from the blood passing through the spleen

The Thymus produces and trains T cells during fetal development and childhood. By the time a person reaches puberty, the immune system is mature and the role of the thymus is diminished. After puberty, the inactive thymus is slowly replaced by adipose (fat) tissue.

Red bone marrow is mostly found in the ends of long bones and in the flat bones of the body. It contains many stem cells that produce blood cells. All of the leukocytes, or white blood cells, of the immune system are produced by red bone marrow.

How Does The Lymphatic System Work?

Fluid Removal

Arterial blood carries oxygen, nutrients, and hormones for the cells. To reach these cells it leaves the small arteries and flows into the tissues. This fluid is then known as interstitial fluid and it delivers its nourishing products to the cells. Then it leaves the cell and removes waste products.

After this task is complete, 90% of this fluid returns to the circulatory system as venous blood.

The remaining 10% of the fluid that stays behind in the tissues as a clear to yellowish fluid known as lymph.

The lymph is moved through the body in its own vessels making a one-way journey from the interstitial spaces to the subclavian veins at the base of the neck.

As it moves upward toward the neck the lymph passes through lymph nodes which filter it to remove debris and pathogens.

The cleansed lymph continues to travel in only one direction, which is upward toward the neck.

At the base of the neck, the cleansed lymph flows into the subclavian veins on either side of the neck.

Assist The Immune System

There are between 500-600 lymph nodes present in the average human body. It is the role of these nodes to filter the lymph before it can be returned to the circulatory system.

Lymphatic vessels carry unfiltered lymph into the node. There waste products, and some of the fluid, are filtered out.

In another section of the node, lymphocytes, which are specialized white blood cells, kill any pathogens that may be present. This causes the swelling commonly known as swollen glands.

Lymph nodes also trap and destroy cancer cells to slow the spread of the cancer until they are overwhelmed by it.

Lymphatic vessels carry the filtered lymph out of the node so that it can continue its return to the circulatory system.

Assist The Digestive System

Another major function of the lymphatic system is the transportation of fatty acids from the digestive system. The digestive system breaks large macromolecules of carbohydrates, proteins, and lipids into smaller nutrients that can be absorbed through the villi of the intestinal wall. Most of these nutrients are absorbed directly into the bloodstream, but most fatty acids, the building blocks of fats, are absorbed through the lymphatic system.

In the villi of the small intestine are lymphatic capillaries called lacteals. Lacteals are able to absorb fatty acids from the intestinal epithelium and transport them along with lymph. The fatty acids turn the lymph into a white, milky substance called chyle. Chyle is transported through lymphatic vessels to the thoracic duct where it enters the bloodstream and travels to the liver to be metabolized.

What Can Go Wrong With Your Lymphatic System?

These are some potential problems that can occur in your lymphatic system:

Lymphadenopathy

This is a condition where the lymph nodes become swollen or enlarged, usually because of a nearby infection. Swollen lymph nodes in the neck, for example, can be caused by a throat infection. Once the infection is treated, the swelling usually goes away. If several lymph node groups throughout the body are swollen, that can indicate a more serious disease that needs further investigation by a doctor.

Lymphadenitis

Also called adenitis, this inflammation of the lymph node is caused by an infection of the tissue in the node. The infection can cause the skin overlying the lymph node to swell, redden, and feel warm and tender to the touch. This infection usually affects the lymph nodes in the neck, and it’s usually caused by a bacterial infection that can be easily treated with an antibiotic.

Lymphomas

These cancers start in the lymph nodes when lymphocytes undergo changes and start to multiply out of control. The lymph nodes swell, and the cancer cells crowd out healthy cells and may cause tumors (solid growths) in other parts of the body.

Splenomegaly (enlarged spleen)

In healthy people, the spleen is usually small enough that it can’t be felt when you press on the abdomen. But certain diseases can cause the spleen to swell to several times its normal size. Usually, this is due to a viral infection, such as mononucleosis. But in some cases, more serious diseases such as cancer can cause it to expand..

Tonsillitis

Tonsillitis is caused by an infection of the tonsils. When the tonsils are infected, they become swollen and inflamed, and can cause a sore throat, fever, and difficulty swallowing. The infection can also spread to the throat and surrounding areas, causing pain and inflammation. A child with repeated tonsil infections may need to have them removed (a tonsillectomy).

How Do Your Keep Your Lymphatic System Healthy?

To keep your Lymphatic System healthy, follow these 3 rules:

  1. Breathe deeply. In the trunk, the diaphragm pushes down into the abdomen when you breathe in. This increased abdominal pressure pushes lymph into the less pressurized thorax.

  2. Get moving. Exercise also ensures the lymph system flows properly because contracting muscles also help to move the lumph.

  3. Drink plenty of water. Without adequate water, lymph fluid cannot flow properly.

This article is part of a series called “Your Body: An Owner’s Manual” which explains how your body systems work and how to maintain them. The first article in the series included a picture of my wife, fitness coach Kathie Lamir, who exemplifies a healthy body. Pictures of Kathie were so well received that I have included one with each article in the series

Fitness Coach Kathie Lamir

Your Body: An Owner’s Manual

There was a time when I didn’t know much more about the human body than that my wife’s was beautiful!

Fitness Guru Kathie LamirSee what I mean?

How strange, I thought. We only get one body. It has to last a lifetime. And the better it works, the better we feel. Why wouldn’t we want to know everything about how it works and how to maintain it?

Yet most of us don’t. We know more about the insides of our car than how our body functions.

Maybe that’s because cars come with owner’s manuals, but your body doesn’t.

Well, problem solved.

This article introduces a 12-part series that will explain how your body works. This series is the instruction manual for your body that you never got.

This initial article will briefly describe the 11 human body systems.

Articles about each of the body systems will follow, one a day. Each article will answer these questions . . .

  1. What Does The System Do?

  2. What Makes Up The System?

  3. How Does The System Work?

  4. What Can Go Wrong With The System?

  5. How Do You Keep The System Healthy?

And each article will include “5 Interesting Facts About The System.”

Before starting this discussion of our body systems, however, you must understand that dividing your body into 11 systems for the purpose of studying them does not mean that they are independent systems. Far from it, they are interconnected and dependent on each other.

In fact, some body parts are part of multiple systems. For example, the long bones (like the femur) are not only part of the skeletal system, but they are also part of the circulatory system because they manufacture blood cells. And the ovaries are part of the endocrine system as well as the reproductive system. More about all of this later . . .

These are the 11 main human body systems, presented in alphabetical order.

Circulatory System

The circulatory system is made up of your heart, blood vessels and blood. Your heart pumps oxygen-rich blood from your left ventricle into your biggest artery, the aorta. From there, the aorta branches into smaller arteries, which then branch into even-smaller arteries that travel all over the body. When blood reaches the smallest blood vessels, called capillaries, an exchange occurs. Oxygen, nutrients and hormones are deposited into the cells and waste material from the cells, such as carbon dioxide, is collected for the return trip to the heart.

Veins carry the blood back to the heart where it enters the right atria, passes through the right ventricle and is sent to your lungs where, in capillaries in the lungs, the waste carbon dioxide is deposited and oxygen is picked up. The newly oxygenated blood returns to the heart and, this time, it enters the left atria. From there it goes to the left ventricle and, from there, it is pumped again .

Click here to learn more about your circulatory system.

Digestive System

Your digestive system consists of organs that break down food into the protein, vitamins, minerals, carbohydrates and fats that your body uses for energy and for building and repairing cells and tissues.

Food passes from your mouth down through a muscular tube called the esophagus, and into the stomach, where food continues to be broken down. The partially digested food passes into the small intestines where it is broken down into nutrients which enter the bloodstream through tiny hair-like projections called villi. The liver, the gallbladder and the pancreas produce enzymes and substances that help with digestion in the small intestine.

The last section of the digestive tract is the large intestine, which includes the cecum, colon, and rectum. Indigestible remains of food are eliminated through the anus.

Click here to learn more about your digestive system.

Endocrine System

The endocrine system is made up of a group of glands that produce the body’s long-distance messengers, or hormones. Hormones are chemicals that control body functions such as metabolism, growth, and sexual development. The glands, which include the pituitary gland, thyroid gland, parathyroid glands, adrenal glands, pineal body, pancreas, ovaries, and testes, release hormones directly into the bloodstream, which transports the hormones to organs and tissues throughout the body.

Click here to learn more about your endocrine system.

Immune System

The immune system is our body’s defense system against infections and diseases. Organs, tissues, cells, and cell products work together to respond to dangerous organisms (like viruses or bacteria) and substances that may enter the body from the environment.

An anatomic response physically prevents threatening substances from entering your body. Examples of the anatomic system include the mucous membranes and the skin. If substances do get by, the inflammatory response goes on attack.

The inflammatory system works by excreting the invaders from your body. Sneezing, runny noses, and fever are examples of the inflammatory system at work.

When the inflammatory response fails, the immune response goes to work. This is the central part of the immune system and it is made up of white blood cells, which fight infection by gobbling up antigens. About a quarter of white blood cells, called the lymphocytes, migrate to the lymph nodes and produce antibodies which fight disease.

Click here to learn more about your immune system.

Lymphatic System

The lymphatic system has three main purposes. It removes excess fluid and waste products from the spaces between the cells and returns them to the blood stream. It aids the immune system in destroying and removing waste, debris, dead blood cells, pathogens, toxins, and cancer cells. And it also absorbs fats and fat-soluble vitamins from the digestive system and delivers these nutrients to be used by the cells of the body.

Click here to learn more about your lymphatic system.

Muscular System

The muscular system is made up of tissues that work with the skeletal system to control movement of the body. Some muscles—like the ones in your arms and legs—are voluntary, meaning that you decide when to move them. Other muscles, like the ones in your stomach, heart, intestines and other organs, are involuntary. This means that they are controlled automatically by the nervous system and hormones—you often don’t even realize they’re at work.

Muscles also generate heat to help regulate your body’s temperature and maintain your posture.

Click here to learn more about your muscular system.

Nervous System

The nervous system is the control system and the network of communication for your body.

Think of your brain as a central computer that controls all voluntary and involuntary bodily functions.

Your “computer” acts through a network that relays messages back and forth from the brain to different parts of the body.

This “network” consists of the spinal cord and nerves. The spinal cord runs from the brain down through the back to nerves which branch out to every organ and part of your body.

When a message comes into the brain from anywhere in the body, the brain tells the body how to react. For example, if you accidentally touch a hot stove, the nerves in your skin shoot a message of pain to your brain. The brain then sends a message back telling the muscles in your hand to pull away. Fortunately, all of this occurs lightning fast.

Click here to learn more about your nervous system.

Reproductive System

The reproductive system allows humans to produce children. Sperm from the male, which is produced in the testes, fertilizes the female’s egg, or ovum, in the fallopian tube. The fertilized egg travels from the fallopian tube to the uterus, where the fetus develops over a period of nine months.

Click here to learn more about your reproductive system.

Respiratory System

The respiratory system brings air into the body and removes carbon dioxide. It includes the nose, trachea, and lungs.

When you breathe in, air enters your nose or mouth and goes down a long tube called the trachea. The trachea branches into two bronchial tubes, or primary bronchi, which go to the lungs. The primary bronchi branch off into even smaller bronchial tubes, or bronchioles. The bronchioles end in the alveoli, or air sacs. Oxygen follows this path and passes through the walls of the air sacs and blood vessels and enters the blood stream. At the same time, carbon dioxide passes into the lungs and is exhaled.

Click here to learn more about your respiratory system.

Skeletal System

The skeletal system has a number of functions, some obvious and some less so. Of course, it supports your body and gives it structure.

However, in addition, your skeletal system works with the bones to allow movement, protects your internal organs, produces blood (in the bone marrow) and stores minerals such as calcium and phosphorous which it releases into the blood when necessary.

Click here to learn more about your skeletal system.

Urinary System

The urinary system eliminates waste from the body, as urine. The kidneys remove waste from the blood. The waste combines with water to form urine. From the kidneys, urine travels down two thin tubes called ureters to the bladder. When the bladder is full, urine is discharged through the urethra.

Click here to learn more about your urinary system.

Oh . . . if you want to learn more from the world’s greatest personal trainer, my wife Kathie Lamir, this is her website.