The human immune system and infectious disease go hand in hand. We, as human beings, are prone to getting sick. You get a fever for a day or two, you take some antibiotics and VIOLA! You feel better albeit a bit weak.
Have you ever wondered how it happens? How your body protects you against infectious diseases and makes you better in no time.
It’s your immune system at work.
The human immune system and infectious diseases are linked. To understand it, however, we first have to build our knowledge of the human immune system and infectious diseases.
In this article, you will learn about the human immune system and infectious diseases, the components of your immune system, and how they all work together to keep infectious diseases at bay. Keep on reading.
Table of Contents
What is the Human Immune System?
All living creatures are vulnerable to disease-causing substances. Even bacteria, which are so tiny that a million of them could fit on the head of a pin, have defense mechanisms against viral infection. As organisms get more complex, this type of defense becomes more advanced.
Multicellular animals have specialized tissues or cells to combat the risk of infection. Some of these reactions take place right away, enabling prompt containment of an infectious pathogen. Although delayed, other reactions are more suited to the infecting agent. These defenses are referred to as the immune system as a whole.
In a world filled with potentially harmful bacteria and infectious diseases, the human immune system is crucial to our survival. Serious impairment of even one component of this system can put a person at risk for serious, even life-threatening infections.
Let’s have a look at the components of the human immune system. The main parts of the immune system are:
White Blood Cells
Your immune system’s main participants are your white blood cells. They originate from your bone marrow and are a component of your lymphatic system.
White blood cells circulate through your body’s blood and tissues, scanning them for foreign invaders (microbes) such as bacteria, viruses, parasites, and fungi. They hunt them down and begin an immune assault.
Lymphocytes, which comprise B-cells, T-cells, and natural killer cells, as well as numerous other immune cell types, are examples of white blood cells.
Antibodies
The body uses antibodies to fight off microorganisms and the toxins (poisons) they release.
They accomplish this by identifying molecules known as antigens that indicate the microbe or toxin as being foreign on its surface or in the chemicals it produces. The antigen is any foreign body carrying an infectious disease. Moreover, these antigens are then designated for eradication by the antibodies.
This onslaught involves numerous cells, proteins, and molecules.
Lymphatic System
The body’s lymphatic system is a network of tiny tubes. The lymphatic system’s primary functions are as follows:
- It controls the body’s fluid levels
- It responds to microorganisms,
- It deals with cancer cells, and cell byproducts that would otherwise cause sickness or diseases
- It absorbs a portion of the dietary fats from the gut.
The components of the lymphatic system are:
- Lymph ducts that transport lymph.
- The colorless fluid that bathes your body’s tissues and includes white blood cells that fight infections.
- Lymph nodes, also known as lymph glands, are structures that trap germs.
Spleen
The spleen is an organ that filters blood, eliminating microorganisms and destroying old or damaged red blood cells. Additionally, it creates human immune system components that combat disease (including antibodies and lymphocytes).
Bone Marrow
The spongy material found inside your bones is called bone marrow. It creates the white blood cells that fight infection, the platelets that aid in blood clotting, and the red blood cells that deliver oxygen throughout our bodies.
Thymus
Your blood gets filtered and monitored by the thymus. T-lymphocytes, a type of white blood cell, are also produced by the thymus.
The Human Immune System’s Other Defenses Against Infectious Diseases
The body contains a number of additional mechanisms in addition to the immune system for defending itself against microorganisms, such as:
Skin
A bacterial-filled oily waterproof barrier
Lungs
Phlegm in the lungs traps foreign particles, and tiny hairs (cilia) wave the phlegm upward to cough it out.
Digestive Tract
The mucous lining contains antibodies, and the acid in the stomach can kill most microbes.
Other Defenses
The body fluids like skin oil, saliva, and tears contain antibacterial enzymes that help lower the risk of infection. Constant bowel and urinary tract flushing is also beneficial.
Read more about immune-boosting foods.
Types of Immune Systems
Three types of immunity exist in humans: innate, adaptive, and passive:
Innate Immunity
Everyone is born with inherent (or natural) immunity, a form of all-encompassing defense. The skin, for instance, serves as a barrier to prevent pathogens from entering the body. Additionally, the immune system can tell when an invader is alien and potentially harmful.
Adaptive Immunity
Throughout our lives, our adaptive (or active) immunity develops. When we come in contact with pathogens or receive vaccine immunization against them, we build adaptive immunity.
Passive Immunity
Passive immunity is temporary and is “taken” from another source. For instance, a newborn is temporarily immune to diseases the mother has been exposed to thanks to antibodies in the mother’s breast milk.
How Does the Human Immune System Work Against Infectious Diseases?
When a pathogen enters and reproduces in bodily cells, infection happens. The immune reaction is frequently triggered by infection. The infection will be removed or confined if the reaction is prompt and efficient, and the disease won’t spread.
Infection and illness can sometimes coexist. In this section, we’ll concentrate on infectious disease, which is defined as an infection that is accompanied by symptoms or other signs of sickness.
The disease can develop when a person’s immune system is weak or compromised. It happens because a pathogen is highly virulent (able to cause host cell damage), and when a large number of infections are present in the body.
The signs and symptoms of an infectious disease might differ widely.
A frequent reaction to infection is fever; a greater body temperature can boost the immune system and provide an unfavorable environment for germs.
White blood cells attack and release chemicals involved in the immune response when inflammation, or swelling brought on by an increase in fluid in the infected area, occurs.
Here’s when the vaccination protects against infectious diseases comes in handy.
The goal of vaccination is to trigger a particular immune response that will produce memory B and T cells that are unique to a particular disease. However, if the virus attacks again, the body may respond quickly and effectively thanks to these memory cells, which remain in the body.
How Does The Human Immune System Get Weak?
There are two ways to describe a weak immune system i.e:
Immunodeficiency
Immunodeficiency is a condition in which the body lacks or improperly functions immune cells of a certain type. A person is more susceptible to infections when this occurs. Secondary or primary (genetic) immunodeficiency is also possible (due to other conditions). Causes of secondary immunodeficiency include:
Medication: steroids, chemotherapeutic medicines, and other immune system suppressants
Medical Diseases: Diabetes, kidney disease, and liver disease.
Infectious Diseases: HIV infection, which can result in AIDS
Other Conditions: undernutrition, surgery, trauma, and old age extremes (newborn and elderly)
Autoimmune Disease
When the immune system overreacts to the body’s own cells and tissues, autoimmune disease results. Autoimmune diseases include lupus, multiple sclerosis, rheumatoid arthritis, and celiac disease.
Disorders of the Human Immune System
Here are some examples of disorders of the immune system:
Severely Compromised Immune System (SCID)
This is an illustration of an immunological disorder that exists from birth. Children are constantly at risk for bacterial, viral, and fungal infections. Sometimes, this condition is referred to as “bubble boy illness.” Additionally, important white blood cells are not present in SCID children.
Temporary Acquired Immune Deficiencies
Some of the developed immune weaknesses are temporary. For instance, several medications can impair your immune system. People taking chemotherapy or other cancer-treating medications may experience this.
Additionally, it can occur in recipients of organ transplants who take medication to avoid organ rejection. Infections like measles, mono (mononucleosis), and the flu virus can also temporarily impair immunity.
Moreover, unhealthy eating habits, alcoholism, and smoking might impair your immune system.
AIDS
An acquired viral infection called HIV, which results in AIDS, kills crucial white blood cells and impairs the immune system.
Moreover, people with HIV/AIDS develop severe infections that the majority of people can fend off. Opportunistic infections are what these infections are known as because they profit from weakened immune systems.
Immunization: Why is Vaccination Necessary?
Vaccination can fight against a variety of infectious diseases to build immunity beforehand.
Vaccines also stimulate the immune system to produce disease-fighting antibodies, providing the benefit of acquired immunity without the need to become ill first. They accomplish this by injecting antigens into the body in the form of an inactivated or dead virus in order to trigger the immune system.
When the body exposes to antigens, the body’s immune system reacts and produces antibodies, which can result in a long-lasting memory that can aid in the body’s ability to fight infections in the future.
Since the novel coronavirus has never been identified in humans, anyone who contracts it may need to go through the entire immune response in order to fight it off. Numerous people have fallen ill and numerous more have died as a result of COVID-19, which may have catastrophic health consequences for some.
Read more about ways to boost your immunity against COVID-19.
Takeaway!
People with weakened immune systems are among those who are most susceptible to illness, whether as a result of advanced age, underlying medical disorders, drugs, or other circumstances.
People with weakened immune systems may be less able to fend off illness, which increases their likelihood of developing COVID-19-type infectious diseases.
However, if there was a way for all of us to train our systems to fight the virus so that we could avoid being sick, it would help the world become a little bit healthier.
However, you can get to know more about infectious diseases and how to prepare your immune system from a well-known general physician by booking an appointment via Healthwire’s platform.
FAQS About Immunity
What Affects Immunity the Most?
Multiple factors like stress, age, body composition, or our lifestyle can affect the performance of our immune system, and any deviation from the normal pattern can affect our immunity. The innate immune system is the first defense mechanism that gets activated immediately when a pathogen enters the body.
Why is Immunity Very Important to Our Health?
The immune system has a vital role: It protects your body from harmful substances, germs, and cell changes that could make you ill As long as your immune system is running smoothly, you don’t notice that it’s there.
What Reduces Immunity?
Infections like the flu virus, mono (mononucleosis), and measles can weaken the immune system for a brief time. Your immune system can get weak by smoking, alcohol, and poor nutrition.
How Does Age Affect Immunity?
As you grow older, your immune system does not work as well. The following immune system changes may occur: The immune system becomes slower to respond. This increases your risk of getting sick.
