The immune system facts


12 Fantastic Facts About the Immune System

If it weren’t for our immune system, none of us would live very long. Not only does the immune system protect us from external pathogens like viruses, bacteria, and parasites, but it also battles cells that have mutated due to illnesses, like cancer, within the body. Here are 12 fascinating facts about the immune system.

1. The immune system saves lives.

The immune system is a complex network of tissues and organs that spreads throughout the entire body. In a nutshell, it works like this: A series of “sensors” within the system detects an intruding pathogen, like bacteria or a virus. Then the sensors signal other parts of the system to kill the pathogen and eliminate the infection.

“The immune system is being bombarded by all sorts of microbes all the time,” Russell Vance, professor of immunology at University of California, Berkeley and an investigator for the Howard Hughes Medical Institute, tells Mental Floss. “Yet, even though we’re not aware of it, it’s saving our lives every day, and doing a remarkably good job of it.”

2. Before scientists understood the immune system, illness was chalked up to unbalanced humors.

Long before physicians realized how invisible pathogens interacted with the body’s system for fighting them off, doctors diagnosed all ills of the body and the mind according to the balance of “four humors”: melancholic, phlegmatic, choleric, or sanguine. These criteria, devised by the Greek philosopher Hippocrates, were divided between the four elements, which were linked to bodily fluids (a.k.a. humors): earth (black bile), air (blood), water (phlegm) and fire (yellow bile), which also carried properties of cold, hot, moist, or dry. Through a combination of guesswork and observation, physicians would diagnose patients’ humors and prescribe treatment that most likely did little to support the immune system’s ability to resist infection.

3. Two men who unraveled the immune system’s functions were bitter rivals.

Two scientists who discovered key functions of the immune system, Louis Pasteur and Robert Koch, should have been able to see their work as complementary, but they wound up rivals. Pasteur, a French microbiologist, was famous for his experiments demonstrating the mechanism of vaccines using weakened versions of the microbes. Koch, a German physician, established four essential conditions under which pathogenic bacteria can infect hosts, and used them to identify the Mycobacterium tuberculosis bacterium that causes tuberculosis. Though both helped establish the germ theory of disease—one of the foundations of modern medicine today—Pasteur and Koch’s feud may have been aggravated by nationalism, a language barrier, criticisms of each other’s work, and possibly a hint of jealousy.

4. Specialized blood cells are the immune system’s greatest weapon.

The most powerful weapons in your immune system’s arsenal are white blood cells, divided into two main types: lymphocytes, which create antigens for specific pathogens and kill them or escort them out of the body; and phagocytes, which ingest harmful bacteria. White blood cells not only attack foreign pathogens, but recognize these interlopers the next time they meet them and respond more quickly. Many of these immune cells are produced in your bone marrow but also in the spleen, lymph nodes, and thymus, and are stored in some of these tissues and other areas of the body. In the lymph nodes, which are located throughout your body but most noticeably in your armpits, throat, and groin, lymphatic fluid containing white blood cells flows through vein-like tubules to escort foreign invaders out.

5. The spleen helps your immune system work.

Though you can live without the spleen, an organ that lies between stomach and diaphragm, it’s better to hang onto it for your immune function. According to Adriana Medina, a doctor who specializes in hematology and oncology at the Alvin and Lois Lapidus Cancer Institute at Sinai Hospital in Baltimore, your spleen is “one big lymph node” that makes new white blood cells and cleans out old blood cells from the body.

It’s also a place where immune cells congregate. “Because the immune cells are spread out through the body,” Vance says, “eventually they need to communicate with each other.” They do so in both the spleen and lymph nodes.

6. You have immune cells in all of your tissues.

While immune cells may congregate more in lymph nodes than elsewhere, “every tissue in your body has immune cells stationed in it or circulating through it, constantly roving for signs of attack,” Vance explains. These cells also circulate through the blood. The reason for their widespread presence is that there are thousands of different pathogens that might infect us, from bacteria to viruses to parasites. “To eliminate each of those different kinds of threats requires specialized detectors,” he says.

7. How friendly you’re feeling could be linked to your immune system.

From an evolutionary perspective, humans’ high sociability may have less to do with our bigger brains, and more to do with our immune system’s exposure to a greater number of bacteria and other pathogens.

Researchers at the University of Virginia School of Medicine have theorized that interferon gamma (IG), a substance that helps the immune system fight invaders, was linked to social behavior, which is one of the ways we become exposed to pathogens.

In mice, they found IG acted as a kind of brake to the brain’s prefrontal cortex, essentially stopping aberrant hyperactivity that can cause negative changes in social behavior. When they blocked the IG molecule, the mice’s prefrontal cortexes became hyperactive, resulting in less sociability. When they restored the function, the mice’s brains returned to normal, as did their social behavior.

8. Your immune system might recruit unlikely organs, like the appendix, into service.

The appendix gets a bad rap as a vestigial organ that does nothing but occasionally go septic and create a need for immediate surgery. But the appendix may help keep your gut in good shape. According to Gabrielle Belz, professor of molecular immunology at the Walter and Eliza Hall Institute of Medical Research in Melbourne, Australia, research by Duke University’s Randal Bollinger and Bill Parker suggests the appendix houses symbiotic bacteria that are important for overall gut health—especially after infections wipe out the gut’s good microbes. Special immune cells known as innate lymphoid cells (ILCs) in the appendix may help to repopulate the gut with healthy bacteria and put the gut back on track to recovery.

9. Gut bacteria has been shown to boost immune systems in mice.

Researchers at the University of Chicago noticed that one group of mice in their lab had a stronger response to a cancer treatment than other mice. They eventually traced the reason to a strain of bacteria—Bifidobacterium—in the mice’s guts that boosted the animals’ immune system to such a degree they could compare it to anti-cancer drugs called checkpoint inhibitors, which keep the immune system from overreacting.

To test their theory, they transferred fecal matter from the robust mice to the stomachs of less immune-strengthened mice, with positive results: The treated mice mounted stronger immune responses and tumor growth slowed. When they compared the bacterial transfer effects with the effects of a checkpoint inhibitor drug, they found that the bacteria treatment was just as effective. The researchers believe that, with further study, the same effect could be seen in human cancer patients.

10. Scientists are trying to harness the immune system’s “Pac-Man” cells to treat cancer.

Aggressive pediatric tumors are difficult to treat due to the toxicity of chemotherapy, but some researchers are hoping to develop effective treatments without the harmful side effects. Stanford researchers designed a study around a recently discovered molecule known as CD47, a protein expressed on the surface of all cells, and how it interacts with macrophages, white blood cells that kill abnormal cells. “Think of the macrophages as the Pac-Man of the immune system,” Samuel Cheshier, lead study author and assistant professor of neurosurgery at Stanford Medicine, tells Mental Floss.

CD47 sends the immune system’s macrophages a “don’t eat me” signal. Cancer cells fool the immune system into not destroying them by secreting high amounts of CD47. When Cheshier and his team blocked the CD47 signals on cancer cells, the macrophages could identify the cancer cells and eat them, without toxic side effects to healthy cells. The treatment successfully shrank all five of the common pediatric tumors, without the nasty side effects of chemotherapy.

11. A new therapy for type 1 diabetes tricks the immune system.

In those with type 1 diabetes, the body attacks its own pancreatic cells, interrupting its normal ability to produce insulin in response to glucose. In a 2016 paper, researchers at MIT, in collaboration with Boston’s Children’s Hospital, successfully designed a new material that allows them to encapsulate and transplant healthy pancreatic “islet” cells into diabetic mice without triggering an immune response. Made from seaweed, the substance is benign enough that the body doesn’t react to it, and porous enough to allow the islet cells to be placed in the abdomen of mice, where they restore the pancreatic function. Senior author Daniel Anderson, an associate professor at MIT, said in a statement that this approach “has the potential to provide diabetics with a new pancreas that is protected from the immune system, which would allow them to control their blood sugar without taking drugs. That’s the dream.”

12. Immunotherapy is on the cutting edge of immune system research.

Over the last few years, research in the field of immunology has focused on developing cancer treatments using immunotherapy. This method engineers the patient’s own normal cells to attack the cancer cells. Vance says the technique could be used for many more conditions. “I feel like that could be just the tip of the iceberg,” he says. “If we can understand better what the cancer and immunotherapy is showing, maybe we can go in there and manipulate the immune responses and get good outcomes for other diseases, too.”


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The human immune system is our protector — its job is to defend the body against diseases and other damaging foreign bodies.

The system works by first identifying alien bacteria, viruses, fungi and parasites lurking in the body, and then sends in its troops — white blood cells — to destroy the invaders and the tissues they infect.

Here are 11 surprising facts about the immune system.

Some people have little to no immune system

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The 1976 film, “The Boy in the Plastic Bubble,” depicts a person with a deficient immune system, who must live out his life in a completely sterile environment because his body is unable to fight infections. Though the story is fictional, the immune system disease — severe combined immunodeficiency (SCID), or “bubble boy disease” — is very real, occurring in about 1 in every 100,000 births.

Bone marrow transplants from a matching sibling donor used to be the only treatment available for patients with SCID, but gene therapy has also recently proved promising.

People long believed fluid imbalances caused diseases

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The germ theory of disease, which correctly states that microorganisms cause some diseases, gained prominence in the 19th century. Before germ theory, humorism (or humoralism) dominated Western medical thinking for some 2,000 years.

The discredited theory proposed that the human body is composed of four liquid substances, or humors: blood, yellow bile, black bile and phlegm. A surplus or deficiency in one or more of these humors causes diseases and disabilities. Disease treatments — such as bloodletting — focused on attempting to restore fluid balance.

The earliest known reference to immunity goes back over two millennia

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The first vaccine was developed in the late 18th century, but people recognized the importance of immunity long before that.

During the plague of Athens in 430 B.C., the Greeks realized that people who had previously survived smallpox didn’t contract the disease a second time. In fact, these survivors were often called upon to attend to those afflicted with smallpox, according to a 1998 article in the International Journal of Infectious Diseases.

In the 10th century, Chinese healers began blowing dried smallpox scabs into the noses of healthy patients, who then contracted a mild form of the disease — and the patients who recovered became immune to smallpox. This practice, which was called variolation or inoculation, spread to Europe and the New England in the 1700s.

Disease symptoms are sometimes the result of your immune system doing its job

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You often hear that bacteria, viruses and fungi are the cause of disease symptoms, but this is technically incorrect. Disease symptoms sometimes occur because your immune system is reacting to the microorganisms.

For example, take the common cold. Your immune system jumps into action when the rhinovirus invades the epithelial cells — cells that line the cavities in the body — in your upper respiratory tract. Immune system chemicals called histamines dilate your blood vessels and increase their permeability, allowing proteins and white blood cells to reach the infected epithelial tissues. However, the inflammation of the blood vessels in your nasal cavity causes nasal congestion.

Additionally, you may get a runny nose because of the increased fluid leakage from your permeable capillaries, combined with an increased mucus production triggered by the histamines.

Your immune system may suffer from lack of sleep

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A healthy immune system is vital to warding off colds, influenza and other ailments. But research over the past few decades consistently shows that sleep deprivation depresses the immune system’s disease-fighting abilities, such as by decreasing the proliferation of cells called T-cells. Even a single night of poor sleep can impair the immune system by reducing the number of natural killer cells.

What’s more, a 2012 study in the journal SLEEP suggested that vaccines may even be less effective for people who sleep less than six hours a night, compared with people who get a full night’s rest, possibly because the loss of sleep leads to a dampened immune system response.

Dairymaids helped spark the development of the first vaccine

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In the 1700s, variolation had become standard practice in Western society. The technique did still sometimes kill people, but the fatality rate associated with variolation was 10 times lower than that associated with full-blown smallpox, according to a 2005 article in the journal Baylor University Medical Center Proceedings.

As the century wore on, tales had started to spread that dairymaids couldn’t get smallpox if they previously suffered from cowpox. Moreover, the fatality rate of cowpox was lower than that of variolation.

This information led English physician Edward Jenner to hypothesize that cowpox protects against smallpox, and that cowpox could be safely transmitted between people as a deliberate way to protect them against smallpox.

So in May 1796, Jenner pioneered the smallpox vaccine. He found a young dairymaid with fresh cowpox lesions on her hands and arms, took pus from the lesions and inoculated an 8-year-old boy. The child developed mild symptoms, including fever and loss of appetite, but he quickly recovered. A few months later, Jenner injected the boy with goo from a fresh smallpox lesion — the child developed no symptoms.

Autoimmune diseases affect mostly women

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An autoimmune disease is a disorder where the body’s natural defenses become hyperactive, attacking normal tissues as if they were foreign bodies. Examples of autoimmune diseases include rheumatoid arthritis, celiac disease and psoriasis.

But the disorders don’t affect men and women equally, according to a 2008 article in the American Journal of Pathology. Approximately 5 to 8 percent of the U.S. population has an autoimmune disease — about 78 percent of these people are women.

Gut bacteria are the key to a healthy immune system

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The human body is home to trillions of bacteria, which outnumber our own cells 10 to 1. In the gastrointestinal tract, these microbes are often beneficial, helping with digestion and synthesizing vitamins B and K. But research has also shown that our gut bacteria help our immune system and keep us healthy in various ways.

For example, the beneficial bacteria prevent pathogenic (disease-causing) bacteria from taking root in our epithelial and mucosal tissues. And these commensal bacteria also train the immune system to better distinguish between disease-causing pathogens and harmless antigens, which may help prevent the development of allergies.

Similarly, the “good” bacteria may influence the immune system’s sensitivity to antigens, potentially helping to prevent autoimmune diseases, conditions in which the immune system attacks the body’s own tissues.

The bacteria also produce useful antibodies and trigger the expression of intestinal proteins, which cause the immune system to repair internal injuries.

Sunlight has complex effects on the immune system

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For decades, scientists have known that exposure to sunlight — specifically ultraviolet (UV) radiation — can suppress the immune system’s response to bacterial, viral and fungal infections. To suppress the human immune system, it takes UVR doses that are only 30 to 50 percent of what’s required to cause barely-detectable sunburn, according to a 2010 article in the Journal of Investigative Dermatology.

At the same time, however, sunlight causes the body to produce vitamin D. A recent study in Nature Immunology suggested that T-cells don’t mobilize if they detect only small amounts of vitamin D in the bloodstream. Additionally, other research suggests vitamin D might induce the production of anti-microbial peptides in the skin — these compounds help defend the body against new infections.

White blood cells only make up a small percentage of your blood

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The immune system is constantly at work to protect you from diseases and fight infections you already have, so you might expect that the system’s soldiers — the white blood cells — would make up a large portion of your blood.

But this is not the case. White blood cells account for only 1 percent of the cells in the 5 liters of blood in an adult’s body.

But don’t worry, there are more than enough white blood cells to get the job done: In each microliter of blood, you have between 5,000 and 10,000 white blood cells.

Immune System 

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The immune system protects your body from pathogens that make you sick like viruses, parasites, and bacteria.

The immune system is made up of cells, organs, and tissues that team up to fight against these invaders.

Your body is exposed to millions of germs every day, and the immune system is the reason they don’t always make you sick.

When germs do make you sick, your immune system works to fight off the infection.

Your body then remembers how to fight the infection if the same germ attacks your body again.

The older you get, the more germs your body becomes protected against. This is called immunity.

White Blood Cells

White blood cells, also called leukocytes, are germ-fighting cells.

There are two types: phagocytes and lymphocytes.

Lymphocytes are divided into B cells, which grow in the bone marrow, and T cells, which grow in the thymus. B cells create antibodies that fight against specific types of germs.

T cells kill off germs by also killing off the healthy body cells that are affected.

T cells also release messengers that send signals to other cells about the invader, kind of like a police officer calling for backup.

Phagocytes attack and kill off germs without destroying body cells. Both lymphocytes and phagocytes patrol the body looking for germs to fight.

When they do find germs, these germ-fighting cells begin multiplying, and T cells send messages to other cells to do the same.

Soon, your body has a whole army fighting against the germs that can make you sick.

Problems with the Immune System

Sometimes, people have problems with the immune system that keep it from working properly.

For example, allergies happen when the immune system overreacts and thinks something harmless, like peanuts or eggs, is dangerous for your body.

Some conditions, like juvenile rheumatoid arthritis and lupus, confuse the immune system and cause it to fight good cells instead of germs.

How to Keep Your Immune System Healthy

Your immune system fights for you without any help, but there are steps you can take to make your immune system’s job easier.

Wash your hands regularly, eat healthy food, stay active, and get plenty of rest.

Sunlight can also help your immune system, and it’s important not to experience too much stress.

80% of your immune system’s activity happens in the intestines.

The cells in your body are marked with a system called Human Leukocyte Antigen (HLA).

Your immune system recognizes these markings and understands that these are your cells and shouldn’t be attacked.

Vaccines introduce viruses that have already been killed or modified into the body.

Your body doesn’t know this, though, so it attacks.

Later, if you ever get the real disease, your body is more prepared to destroy it.

Your skin is your body’s first line of defense.

It has special cells that can warn the body about incoming germs, plus glands that can kill some bacteria.

Your saliva (spit) and the tears in your eyes also have special chemicals that can break down many viruses and bacteria.

Mucus in your nose, throat, and lungs traps bacteria as well, and the acid in your stomach kills most germs. Your body works hard to keep you healthy and safe!

Human body

Fun Facts About the Immune System

Your immune system is your body’s version of the military: sworn to defend against all who threaten it, both foreign and domestic. It has some really interesting soldiers that help make this possible.

Your immune system protects against disease, infection, and helps you recover after an injury.

A river of blood and lymph

The immune system is a complex fighting system powered by five liters of blood and lymph. Lymph is a clear and colorless liquid that passes throughout the tissues of the body.

Together, these two fluids transport all the elements of the immune system so they can do their jobs.

White (knight) cells

Like white knights slaying a dragon, white blood cells charge into battle at any sign of trouble. There are two different types of white blood cells: phagocytes and lymphocytes.

Phagocytes can move through your blood vessels and tissue to ingest or absorb invaders. Phagocytes target organisms that cause disease (or pathogens) and toxins. Toxins are a natural poison produced by some organisms as a form of protection. Sometimes when a phagocyte has absorbed a pathogen, it sends out a chemical that helps lymphocytes identify what kind of pathogen it is.

Each pathogen carries a specific type of antigen, and each lymphocyte in your body carries antibodies meant to fight the antigens carried by pathogens. There are three main types of lymphocytes in the body: B cells, T cells, and natural killer cells.

B cells create antibodies that attack bacteria, viruses, and toxins that enter the body. T cells kill cells in the body that have been overtaken by viruses or that have become cancerous. Like T cells, natural killer cells kill infected or cancerous cells. But instead of producing antibodies, they make a special enzyme, or chemical, that kills the cells.

Your body creates new antibodies whenever it’s infected with a new antigen. If the same antigen infects you a second time, your body can quickly make copies of the corresponding antibody to destroy it.

These brave soldiers only live up to a few weeks, so it’s a good thing there’s a lot of them — a single drop of blood can contain up to 25,000 white blood cells.

Fever and inflammation are good signs

Having a fever and inflammation can be unpleasant, but they’re signs that your body is doing its job. Fever releases white blood cells, increases metabolism, and stops certain organisms from multiplying.

Inflammation occurs when each damaged cell releases histamines. The histamines cause the cell walls to dilate. This creates the redness, heat, pain, and swelling of inflammation. As a result, your body limits the effects of the irritant.

Sleep now or forever hold your peace

Have you been running around like crazy, and suddenly find yourself sick? That’s your immune system getting its revenge.

If you’re not getting more than five hours of sleep a night, your immune system can become depressed, just like you. This leaves you open to colds, flu, and infection.

Some sun is good

Exposure to sunlight is how your body naturally produces vitamin D. This helps ward off an array of bad things like depression, heart disease, and certain cancers. It’s even good for people with autoimmune disorders.

A fair-skinned person only needs about 10 minutes on a sunny day to get all the vitamin D they need. However, too much sun can cause temporary damage to your immune system and eventually lead to skin cancer. Remember some sun is good, but you need to protect your skin when you plan to spend time outside.

Skincare experts recommend all people wear sunscreen with broad-spectrum UVA and UVB protection, Sun Protection Factor (SPF) 30 or higher, and water resistance. When the sun is very strong, you should also wear protective clothing, such as:

  • long-sleeved shirts
  • long pants
  • wide-brimmed hats
  • sunglasses

Also, stay mostly in the shade when the sun’s rays are strongest, between 10 a.m. and 2 p.m.

Stress damages your immune system

Your immune system is ready for anything you can throw at it. But it can only handle so much.

Stress has a significant effect on your immune system. During stress, a series of events release cortisol, adrenaline, and other stress hormones from the adrenal gland. Together they help your body cope with stress. Normally, cortisol is helpful because it decreases the inflammation in the body that results from the immune responses caused by stress.

But if a person is chronically stressed, stress hormones can affect the way the body functions over time. This increases your risk of health problems, including:

  • anxiety
  • depression
  • digestive issues
  • heart disease
  • sleep disorders
  • weight gain
  • problems with memory and concentration

It’s important to find healthy ways to deal with your stress. This will decrease your risk of long-term stress and its related health problems. Some good ways to reduce stress include:

  • meditation
  • yoga
  • acupuncture
  • talk therapy
  • art therapy
  • exercise
  • eating healthfully

Laughter helps your immune system

The saying goes that laughter is the best medicine, and there’s truth to that. Laughter releases dopamine and other feel-good chemicals in the brain, all of which can help decrease stress.

Twenty minutes of laughter a day may not keep the doctor away, but it may help keep your immune system working properly.

Germs keep you healthy

Your gut is filled with tons of bacteria and other things to help you digest your food. But germs outside your body are normally regarded as vile and disgusting. While some of this may be true, you need those germs to stay healthy.

Your immune system can adapt, which is why human beings have been around for so long. Once your body comes in contact with a foreign substance, it attacks it and remembers it. If it comes back, your body knows what to do. This is most apparent with measles: one infection is usually enough to protect you for life.


Anyone who experiences seasonal allergies or hay fever probably wants to curse every molecule of pollen or dander around them. These microscopic particles cause the release of histamines, which create some of the nasty symptoms of allergies.

Allergies don’t affect everyone. They’re caused when your body mistakes something harmless, such as pollen or a type of food, as a pathogen. Your body launches an immune response against it, causing you to experience allergy symptoms.

Autoimmune disorders

Sometimes your immune system attacks the tissues in the body, causing disease. This is called autoimmunity.

Most people’s immune systems get used to their own tissue before they are born. They do this by turning off the cells that would attack them. Autoimmune disorders are when the body mistakenly attacks healthy tissue. This is what occurs in people with autoimmune diseases such as:

  • multiple sclerosis
  • lupus
  • rheumatoid arthritis
  • psoriasis

These diseases are treated with drugs that suppress the immune system.

Keeping your immune system strong

Your immune system works hard to protect you every day, but there are things you can do to help it out:

  • Get a good night’s sleep. Your body can’t function correctly if you aren’t sleeping well.
  • Practice good hygiene. Washing your hands regularly can prevent infections.
  • Eat a balanced diet and get plenty of exercise. Eating nutritious food and staying active will help your body fight off infections.

4 cool facts about your spleen

The most common bacteria that cause infections in people without a functioning spleen function are pneumococcus, meningococcus and Haemophilus influenzae type B. These bacteria can be transferred from person to person through droplets of saliva or mucus, such as when a ‘carrier’ sneezes or coughs near or on you. In a healthy person, this rarely causes illness, however vulnerable people – such as those living without a functioning spleen, may become ill if their immune system is unable to keep the bacteria in check.

If a person has had their spleen removed, is born without a spleen (asplenia), or is diagnosed with a spleen that is not working (hyposplenism), they have an increased lifelong risk of bacterial infections. Keep reading to find out what life is like without a spleen and what extra care must be taken to protect the body.

3. The blood vessels in the spleen are able to expand and contract, depending on your body’s needs

The spleen stores blood and when a person loses a lot of blood, for example in a bad car accident, the spleen can respond by releasing blood back into your blood system.

The healthy adult spleen weighs around 200g. However, it can become significantly larger when a person is unwell. Certain medical conditions place great strain on the spleen and make it big (splenomegaly). Some reasons for an enlarged spleen are infections (malaria), liver disease and some blood cancers.

Glandular fever has also been known to make spleen large and very rarely can lead to a spontaneous rupture. Fractured ribs, from for example a car accident, can lead to the spleen being punctured by one of the pointy ends of the rib. If this happens it can be life threatening as a large amount of blood can go into the abdomen and leave the circulating blood stream. This type of bleeding can be potentially fatal and surgery to remove the spleen (splenectomy) is often done in an emergency.

4. It is possible to live without your spleen

That’s right, it is in fact possible to live without a spleen – 3,000 Queenslanders are currently living without a spleen or with reduced spleen function.

Brisbane nurse Carolyn Hartwig has been living without a spleen since undergoing surgery nearly 30 years ago to treat a rare medical anomaly.

She is a passionate advocate for the Spleen Australia registry, which aims to prevent serious infections in people living without a functioning spleen through support and education.

Ms Hartwig said before joining the spleen registry, she was unaware of how much important information she was missing out on – which meant she was not actually up to date with her required immunisations, did not possess a medical alert card or bracelet and did not have access to emergency antibiotics.

“I have always been fairly aware of the importance of self-care after my splenectomy and had thought I was well informed. I was however not as well informed as I should have been,” she said.

“Due to my registration with Spleen Australia, my family and I now have an increased awareness of everything from the immunisations I need to have, to the importance of seeking medical attention in the event of a cat scratch or dog bite.

“The ability to now phone Spleen Australia to clarify guidelines for annual influenza immunisations and other boosters for my individual circumstance has been invaluable. The Spleen-ie App is also so helpful to refer to, knowing that my personal immunisation records can be easily found.”

Registering with Spleen Australia

If you do not have a spleen, or have a spleen that doesn’t work, you can register with Spleen Australia to access information and support to assist with managing this aspect of your health.

Registered patients will receive:

  • medical information on managing asplenia or hyposplenism.
  • a credit-card sized ‘spleen alert card’ – to be carried at all times in case of emergencies – as well as other educational material.
  • an annual newsletter providing reminders for flu vaccinations and booster vaccinations.
  • access to phone support for questions, via 1800 SPLEEN (1800 775 336) information on where in Queensland they can access medical advice for overseas travel.

Important resources

10 Amazing Facts About Your Immune System

The immune system is made up of a network of cells, tissues, and organs that work together to protect the body against infection and maintain overall health.

The human body is an optimal environment for pathogens, such as bacteria, viruses, fungi, and parasites to thrive. The immune system works to limit these microbes’ access to the body and prevent them from growing and causing illness.

While most people know the basic function of the immune system, there are many intricacies about your body’s natural defense system that you may not be aware of.

Here are 10 amazing facts about the immune system:

1. Each part of the immune system has a unique function.

“Think of the immune system like the military,” says Dat Tran, MD, an immunologist and assistant professor of pediatrics at the University of Texas Health Science Center at Houston. “There are different branches that each serve a unique function in protecting the body.”

The first line of defense, Dr. Tran says, is the white blood cells, which are the first to recognize pathogens and fight off infection. Lymphocytes, a specific type of white blood cells, work to allow the body to remember the invading microbes to fight them faster in future infections.

Other parts of the immune system include the bone marrow, where white blood cells are produced; lymph nodes, which produce and store infection-fighting cells throughout the body; and the spleen, which helps control the amount of blood in the body and cleans out old or damaged blood cells from the body.

2. Vaccines play an important role in educating your immune system.

Vaccines work by stimulating the immune system to produce antibodies against a foreign invader without actually infecting the individual with the disease. As a result, when the body encounters that infection in the future, it knows how to fight it off.

“Vaccines educate the immune system using a unique component of that pathogen so, upon exposure to that pathogen in the future, you have very minimal to no symptoms,” Tran says.

3. Every day, we encounter billions of germs, but they’re not all bad.

Though it may not be pleasant to think about, countless microbes live on and in our bodies, and they are actually necessary to maintain good health.

“Good bacteria in our body provides us with nutrients we need and also provides a defense against bad bacteria and infection,” Tran says. A balance needs to be maintained because when good bacteria is reduced, bad bacteria can take over, making us feel sick, he says.

4. Stress can affect the way your immune system works.

Stress can lead to increased levels of cortisol, a steroid hormone that is important for overall function of our body; but too much of it can lead to a number of health problems, including decreased immunity. “The high level of steroids can blunt your immune system,” Tran says.

5. Positive emotions and a healthy lifestyle may boost your immunity.

Some research suggests that optimism can actually make our immune system work better. “I don’t know if it’s a direct cause,” Tran says, “but the happier, or more positive you are, the more likely you are to eat right and be less stressed, which will help your immune system.”

RELATED: Best Foods for a Healthy Immune System

6. Sleep deprivation can impact immunity.

Not getting enough sleep can wreak havoc on the body, and the immune system is no exception. Studies show that a lack of sleep may make you more likely to catch a cold and also makes it more difficult to fight off infection.

7. Allergies are the result of your immune system reacting to a false alarm.

When you experience an allergic reaction, your immune system is responding to a harmless allergen that it perceives as a threat. Symptoms of an allergic reaction, which can range from a runny nose to breaking out in hives to fainting, are a result of the body’s misguided attack.

8. Your immune system can attack itself.

Autoimmune diseases occur when the immune system destroys its own healthy tissues. In such cases, white blood cells in the body cannot distinguish between pathogens and the body’s normal cells, setting off a reaction that destroys healthy tissues.

While there are over 80 different types of autoimmune disorders, common ones include rheumatoid arthritis, psoriasis, and Crohn’s disease.

9. Women are more likely to be diagnosed with autoimmune diseases.

Autoimmune diseases affect about 8 percent of the population in the United States, making up the third most common category of disease after cancer and heart disease, according to the U.S. Centers for Disease Control and Prevention. Women make up nearly 80 percent of those living with autoimmune diseases. While the cause of autoimmune diseases is unknown, it is generally believed to have a strong genetic component, and women in their child-bearing years are at the highest risk.

10. Being too clean can inhibit your immune system from functioning properly.

Cleaning and disinfecting may seem like the best way to avoid infection, but this is a case where there can be too much of a good thing.

“When you make your environment so clean, you minimize so many foreign pathogens that you actually minimize the development of the immune system,” Tran says. This is especially the case with young children, since if they’re not exposed to harmful microbes at all, their bodies won’t be able to develop the proper antibodies to fight them off.

Tran recommends his patients practice good hygiene but warns not to go overboard. “I tell them to live their lives normally,” he says. “If someone has a cold, definitely wash your hands around them and try to avoid direct contact. Clean normally, but don’t be obsessive about it. While trying to avoid foreign pathogens, you don’t want to unintentionally minimize the good bacteria in your environment.”

Your immune system is a complex network made up of an array of cells and biological compounds that work together to keep you healthy as your body comes into contact with foreign “invaders” of all sorts—bacteria, viruses, fungi, allergens, toxins, and more. Your immune system is tasked with identifying harmful substances and getting rid of them all while letting benign substances, like food and good bacteria, pass through the body naturally. You probably don’t even think about your immune system until you get sick, but here are 5 surprising facts about your immune system that you can use to help stay healthy.

#1 80 Percent of Your Immune System Is in Your Gut
Your immune system is housed largely within your lymphatic system, which is a network of vessels and glands found throughout most of your body and concentrated in and around your gut—in the gut-associated lymphoid tissue (GALT). It may sound strange at first, but when you think about how much food passes through your digestive system—and that food carries microbes, potential allergens, and toxins into the body—it makes sense that your immune system would be concentrated in your gut.

The immune system in your gut is hard at work identifying those substances and organisms that must not enter the body so that nutrients can be absorbed and good bacteria can set up shop in your gut to keep you healthy. If you continually eat foods that your immune system identifies as harmful—or foods that feed harmful bacteria in your gut—you’ll throw off your immune balance and be prone to illness. Likewise, if you don’t support your gut bacterial balance by replenishing the good bacteria, your immune system won’t receive the right messages and will mount an immune response against seemingly benign substances like foods and even your own body.

#2 Inflammation Is Your Immune System’s First Responder

When your immune system encounters a substance it identifies as a foreign invader, the first responders, so to speak, are those cells and biological compounds involved in the process of inflammation. The inflammatory response is a rapid, somewhat messy reaction that destroys almost everything in its path, including healthy cells and tissue, in order to destroy the perceived foreign invader. While this process can be life-saving, when inflammation is chronic, healthy tissues become damaged and disease can set in. A healthy immune response involves a rapid inflammation response that resolves soon after it begins.

#3 A Fever Means Your Immune System is Working

When your immune system encounters a viral or bacterial infection that requires a strong immune response, it may need to raise your body temperature to effectively eliminate the organism, which has a difficult time surviving at higher temperatures. So if your first response to a fever is to take fever-reducing medication, you may not actually be helping fight your illness. Talk with your doctor about when such medication is necessary, and when you can withstand a fever to help your immune system work as it is designed.

#4 Avoiding All Germs Is Not Good for Your Immune System

Getting sick does not necessarily mean that your immune system is impaired. In fact, coming into contact with certain microbes actually helps prime your immune system so that it responds better to future encounters with microbes. It’s how you build stronger immunity. If you rarely come into contact with germs, your body will have a hard time mounting a response against them once you do encounter them, and you may get even sicker than you would have if your immune system had already fought a similar illness or come into contact with a variety of microbes.

This concept is known as the hygiene hypothesis, an idea that emerged from research comparing children raised in ultra-sanitized environments to children raised in environments rich in microbes. Those children raised in ultra-sanitized environments have higher rates of allergenic illnesses like asthma, eczema, and allergies (all of which involve an imbalanced immune response).

#5 Vitamin D is Your Immune System’s Best Friend

Most people think of vitamin D as a bone-building nutrient, and they’re not wrong. But vitamin D plays many important roles in the body. One of vitamin D’s superpowers is to help balance immunity. If you haven’t checked your vitamin D level yet, ask your doctor to do so at your next visit. Most people need more than the daily recommended amount to maintain a healthy vitamin D level. If you get sick often, your vitamin D level could be low. It’s worth checking.

Follow these five tips to keep your immune system working. Follow a healthy diet rich in fiber and vitamins. Here’s diet program I designed to keep your gut healthy

  • Getting under 5 hours of sleep a night has been shown to greatly depress immune function in your body.
  • Studies show that people who lack humor in their lives tend to have less protective immune responces.
  • Toxins such as air pollution, pesticides and even second-hand cigarette smoke can affect your body’s natural defense system.
  • In your blood, there are around 50 billion white cells whose only interest is to keep your body’s natural defences in good condition, so don’t worry if you lose 5 billion when you give blood – you still have a few left.
  • When your catecholamine and CD8 levels change, these levels can suppress the immune system.
  • Dieting decreases natural killer cell functionality, therefore weaking the immune system.
  • Regular messages have been shown to increase the number and aggressiveness of NK cells and protective antibodies, thereby giving the immune systems a boost.
  • While the body needs some sunlight to produce vitimin D, too much sunshine can suppress the immune system.
  • Even after just one month of quitting smoking, smokers can strengthen the immune system – experiencing an increase in immune cell activity and a decrease in the stress hormone cortisol.
  • The number one way to boost the immune system is to reduce stress.

Are you the sort of person who is constantly unwell, and finding yourself always picking up colds or the flu? If you are then it’s more than likely you have a weak immune system, and this is something you need to work on improving. Our immune system is incredibly complex, and it’s the thing that prevents us from getting ill, as well as helping us get better once we are ill.

In fact, were it not for our immune system, none of us would live particularly long, and it’s essential for keeping us healthy. As we established before, some of us have better immune systems than others, and these are the people who always seem to be healthier. These are some of the truly stunning facts you never knew about the body’s immune system.

It’s packed with specialized blood cells

Your immune system is constantly working overtime to ensure that your body is fit and healthy as much as possible. And, the greatest weapon the immune system has is specialized white blood cells known as lymphocytes, and phagocytes – these work to create antigens, and ingest harmful bacteria respectively. White blood cells attack pathogens in the body, and help to keep you strong, healthy, and able to fight off disease.

Fantastic facts about the immune system

It’s linked to the spleen

There is a direct link between the spleen and the immune system; in fact, the spleen actually helps the immune system to work. Yes, you can live without a spleen, but you really need to keep hold of yours if you want your immune system to be operating at the best possible level. This is because the spleen is basically like one giant lymph node that produces new white blood cells, and removes the old ones from the body. It is an essential tool in helping with the immune system’s functionality.

It affects your mood

Believe it or not, your immune system can have a major impact on your mood and how you are feeling. There are so many wonderful things to know about the immune system, but the fact that it impacts on social behavior and interaction shows how big of a role it plays. Your mood and friendliness could well be affected by how well your immune system is working. As long as the body is fighting off illness and bacteria, it should leave you in a much more sociable mood.

Fantastic facts about the immune system

It can be tricked

Incredibly, the immune system can actually be tricked, and this is something doctors, and scientists are exploiting in order to come up with other forms of treatment. For instance, a new form of therapy for Type 1 diabetes actually tricks the immune system. This is done by introducing new pancreatic cells to replace those attacked by diabetes – it manages to do this without triggering an immune response.

As you can see, there are loads of cool things you never knew about the body’s immune system. You’ve got to make sure you do as much as possible to understand why your immune system matters so much – not to mention doing your best to keep up your vitamin intake.

Fun Facts About Your Immune System (And How Probiotics Help Support It)

Immune system maintenance is key to our overall health, but how much do we know about it? Check out these helpful facts below if you want to learn more
about your immune system, and why probiotics can help keep it in top shape.

  1. 80% of your immune cells are in your gut

    The microbes that live in your digestive system play a major role in supporting regular immune system responses. Researchers found that when exposed to bacterial spores, immune system cells called B lymphocytes began dividing
    and reproducing.1 These B cells are key to overall immune system health because they produce antibodies against potentially harmful bacteria.

  2. Our immune system encounters billions of germs every day

    While that may seem terrifying, it’s actually healthy to expose ourselves to bacteria. Many microbes are good—if not essential—for balancing out your
    immune system. The “good” germs help support our immune barriers, and
    when they’re reduced, the “bad” germs may compromise your system.2

  3. Stress can affect our immunity

    Increased levels of cortisol may lead to chronic inflammatory responses, especially if your anxiety lasts over a long period of time. That’s because the habitual excess cortisol in your blood causes an immune resistance to the hormone, which can build up tissue inflammation throughout your body.3

  4. Probiotics may help tissue continue to act normally

    Studies have shown that probiotics can help maintain the normal balance of C-reactive proteins in the blood. These proteins are essentially alarms that go off when unfamiliar or unwanted cells enter the body. They’re critical to continued health, but in excess, they can cause unnecessary, unwanted inflammation.4,5

  5. Immune cells exist in your skin, too

    These specialized cells detect invasion by foreign microbes. Certain cells, called mast cells, use histamine to signal the immune system of the presence of any detectable foreign bodies . This can result in physical effects on your skin.6

Thankfully, taking a probiotic supplement can help maintain the balance of healthy microbes in your body, which may ultimately help support normal immune system responses. For an overall boost of beneficial microbes, we suggest trying a potent probiotic supplement with many unique strains paired with billions of cultures.

5 Interesting Facts About The Immune System

Think you know everything about the immune system?

You might be surprised to learn the following facts about the immune system—your body’s natural defense against diseases and infections.

1) The Immune System Should Not Be Taken for Granted

Did you know that some people have no immune system?

Having no immune system is not due to disease. Some people are just born without or with very little ability to naturally fight infections.

It’s a condition that exists in 1 out of 100,000 births.

2) The Common Cold vs. the Immune System

Another interesting detail about immune health is that sometimes there are symptoms that are mistakenly believed to be a disease even though they are just a manifestation of the immune system’s functioning.

The best example for this is arguably the common cold. The cold itself is not the disease, but the sign of the immune system fighting the invasion of rhinoviruses on the epithelial cells that line the surfaces of your body.

What happens is that the immune system secretes histamines to dilate the blood vessels, enhancing their permeability to enable proteins and white blood cells access to the infected epithelial cells.

The symptoms are not caused by the cold itself, but rather by the body’s production of histamines to fight off the cold.

3) The Benefits of Bacteria

Did you know that bacteria in your stomach helps enable a healthy immune system?

The human body naturally houses trillions of bacteria and other microbes. Many of them are beneficial as they assist in digesting food and in synthesizing vitamins.

They also prevent pathogenic microorganisms from thriving in the epithelial and mucous tissues.

4) The Power of the Sun

Exposure to the sun is a great way to improve the functionality of one’s immune system.

Not only does sunlight aid in the production of vitamin D, but it can also improve the mobility of T-cells that are active participants in the body’s immune response.

5) Tips to Boost Immunity

There are many natural health supplements formulated to help effectively boost immunity. Those that contain the mushroom Agaricus Blazei Murill, for example, are proven to be effective in enhancing the immune response.

Agaricus Bio® is a line of Agaricus blazei Murill supplements that supports a strong immune response by naturally activating various immune cells to relentlessly attack invading pathogens. Click the products below to find out how Agaricus Bio® can supercharge your immune system today.

0 Shares This is a Lymphocyte. A lymphocyte is a kind of white blood cell in the vertebrate immune system

To keep itself healthy the body is designed to build immunity. The definition of immunity is to be protected against something. This system of the body involves different organs and also partners with the blood system. It is in charge of keeping the entire body safe from the invading germs that it is attacked by every day.

1. Built Like a Fortress

The immune system includes the skin, white blood cells, and the lymph system. They work together to defend the body against attacks by germs and bacteria. Since they are constantly patrolling and increase defenses when necessary, they are very similar to a protected building like a fortress.

2. The Skin – First Protection

The first defense the body has to germs is the skin. The body’s covering works like a guard against harmful bacteria. Since it is commonly the first place germs attack, keeping it clean is the best way to stay healthy. This is why doctors and nurses wash their hands so often, to keep the germs from spreading to other people on their skin.

3. White Blood Cells – The Soldiers

White blood cells patrol the blood like soldiers. Other types of white blood cells are sent to attack germs and bacteria once they are detected in the body. White blood cells only live for a few weeks, so the body has to make more all the time. Luckily there are lots to go around the blood system, in one tiny drop of blood there can be up to 25,000 of those cells. The three types of white blood cells are; lymphocytes, neutrophils, and macrophages.

4. Lymphocytes – The Special Warriors

The lymphocytes are white blood cells that attack both viral and bacterial infections. There are two types of lymphocyte; the T cells and B cells. T cells seek out germs or unhealthy cells that are hiding and destroy them. The B cells make antibodies which look for a specific germ. When they find that germ the antibody attaches to it that way the other white blood cells know it needs to be killed.
5. The Lymphatic System – Travel Way for The Immune System

Throughout the body is the lymph system that is a travel way carrying lymph fluid to parts of the body. It picks up bacteria and viruses and carries them to areas called lymph nodes. These glands collect the bad stuff and destroy it before it travels to other parts of the body. The lymph system also works as a travel way for white blood cells that are on their way to battle.

6. Some Germs are Good

Germs can make you sick but they also help to strengthen your immune system. Once your body is attacked by a germ it remembers it. This way if it comes back the body is prepared to fight it. Since the body can adapt this way it is important that the body is exposed to some germs.

7. Allergies – When the Immune System Works Too Hard

Sometimes the immune system can attack too much. That is what happens when a person is allergic to something. Allergic reaction is when the immune system reacts to something like its a bacteria or virus. Instead of a real threat it is just fighting an ordinary thing like nuts or grass. The reaction causes symptoms like sneezing, itching, runny nose, sore throat, hives, and stomach cramps.

8. Attacking the Wrong Cells – Auto Immune Disorders

Another way that the immune system can misbehave is when it attacks healthy cells. When a person has an auto immune disorder, their body attacks its own cells like they are bad. Depending on what cells are attacked this can cause a variety of health issues and has to be controlled by medication.

9. Rest and Relaxation – Helping the Army Stay Strong

Two of the most important ways to keep the immune system healthy are to reduce stress and get enough sleep. Studies show that getting less than 5 hours of sleep a night makes the immune system work slower. Stress also slows the immune system down and should be avoided.

10. Vaccines – Helping the Immune System

When immunizations are given to people it is usually to expose them to a germ that their body can prepare a defense against. If they are attacked by that same type again, their body is ready and will be less likely to get sick. The germs in the shot are usually “dead” forms of a virus so they have less chance of making the person sick. Even just having them in the body allows the immune system enough chance to remember the germ if it is attacked by it later. Since some contagious illnesses can kill, preparing the body with vaccines can save lives.


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