Immune System Specifications and Components

Today, Healthy life publishes an important article, Immune System Specifications and Components, written by Dr. Safia, Khyber Girls Medical College, Pakistan.

Our body has a powerful protective army that protects it from various types of threats. These threats can come in the form of mechanical injuries, the entry of germs, or the entry of other foreign particles like dust. This personal army is called the immune system. Every day, we encounter a vast number of bacteria, viruses, and other disease-causing organisms. However, we do not fall ill every other day due to our immune system. Here we will try to answer the question, what is the Immune System Specifications and Components.

Parts of Immune System/Immune System Specifications and Components  

The immune system can be broadly divided into two parts; 1. Innate immunity or Non-Specific Immunity and 2. Adaptive immunity or acquired immune system

1. Innate Immunity or Non-Specific Immunity

Innate immunity is also known as non-specific immunity. This type of immunity is the body’s first natural defense against any foreign particle or organism. This system plays a vital role in the immune system. This system killed all foreign intruders. Its primary goal is to prevent any intruder from entering the body, and if it does enter, then the immune system kills this intruder. It does not differentiate between one pathogen and another. There are different components of this type of immunity.

Components of Innate Immunity

Following are different components of innate immunity.

a). Skin

The first component of this defensive system is our skin. Any organism trying to get into the body is stopped by the skin, our largest organ, which covers us.

b). Mucous Lining

Secondly, there is the mucous lining of all our organs. The sticky, viscous fluid of this lining traps any pathogens trying to get past it. These are the physical barriers. However, we also have chemical barriers, such as the lysozyme in the eyes, or the acid in the stomach, which kill pathogens trying to gain entry. The genitourinary tract and other places have their normal flora or microbial community. These compete with pathogens for space and food, and therefore also act as a barrier.

c). Inflammation by Mast Cells

After the mucous lining of defense, another component is inflammation, which is done by mast cells. These cells are constantly searching for suspicious objects in the body. When they find something, they release a signal in the form of histamine molecules. These alert the body, and blood is rushed to the problem area. This causes inflammation and brings leukocytes, or white blood cells, which are soldiers in our body’s cellular army.

One of the strange things about this system is that sometimes when such an intruder enters into the body, which is not a germ, but rather a harmless thing like a dust particle. However, with the entry of such harmless particle, this system performs its duty and give a complete response against such particle. As a result, an allergic reaction occurred in the body

d). Leukocytes

In the fortress of our body, the Leukocytes are VIPs. They have an all-access pass to the body, except, of course, to the brain and spinal cord. Our leukocytes come in many types. Those that belong to the innate system are the phagocytes. These cells can either patrol our body, like the neutrophils, or they can stay in certain places and wait for their cue.

e). Neutrophils

Neutrophils are essential and the most abundant cells of the body. They guard and protect the body and can therefore get to a breach site very quickly. These cellular soldiers kill the infectious cell and then die, which leads to pus formation.

f). Macrophages

There are also the big dire wolves or the Macrophages. These cells are like hungry, ravenous monsters who engulf unwanted pathogens. They are collected in certain places instead of roaming freely in our blood. These cells can consume about 100 pathogens before they die, but they can also detect our cells that have gone rogue, such as cancer cells, and kill them too.

g). Natural Killer Cells

Beyond that, we also have the Natural Killer Cells. These cells can efficiently detect when our cells have gone rogue or are infected with, say, a virus. Natural Killer Cells detect a protein produced by normal cells, called the Major Histocompatibility Complex or MHC. Whenever a cell is not normal, it stops producing this protein. The Natural Killer Cells move around constantly, checking our cells for this type of deficiency, and when they find an abnormal cell, they bind to it and release chemicals that will destroy it.

h). Dendritic Cells

The last cells of our innate immune system are the Dendritic Cells. These are found in places that contact the outside environment, such as the nose, lungs, etc. They are the link between our innate and adaptive immune systems. They eat a pathogen and then carry information about it to our adaptive immune system cells. This information is produced and shared in the form of antigens.

Antigens are the traces that pathogens leave around. They are molecules found on the surface of pathogens detected by our adaptive immune system for recognition. The dendritic cells pass on this information to our T cells. However, macrophages can also perform this function.

2. Adaptive immunity or acquired immune system

This system is more efficient, as it can differentiate between different pathogens. It has two main components; T – lymphocytes and B – lymphocytes.

a). T Lymphocytes or T-Cells

T-cells come into play when an infection has already occurred, thus bringing about the cell-mediated immune response. Some T-cells take signals from the dendritic cells or macrophages and are thus called helper T-cells. They perform two essential tasks: forming effector T-cells, which are primary cells that cycle through the body and call in the cavalry, namely other white blood cells. Helper T-cells also form memory T-cells, which keep a record of this antigen for future reference. Sometimes, some cells of our body know that they have lost the battle. Essentially, the affected area or organ has become heavily infected with pathogens, so there is no hope for them. At this point, the immune system brings out the cytotoxic T- cells. These cells rush over and perform a mercy killing for the infected and dying cell.

b). B Lymphocyte or B-Cells

Furthermore, we have the B-cells. B-cells join the fight when the pathogens have entered but have not yet caused any disease. This is called the humoral immune response. They produce chemicals called antibodies, which fit the antigens of pathogens, much like how a lock and key fit together. These antibodies crowd around a pathogen and act like tags. They signal the macrophages to come and kill the marked pathogen. B-cells also produce memory B-cells when they encounter an antigen. The B- and T- memory cells jointly maintain a record of all encountered infections and strengthen and solidify the body’s immune response to these infections.

Our innate immune response is quicker, though non-specific. It gets into action within hours and is pretty strong. However, when things get out of hand, the innate system calls for help from the acquired immune system. This system can take days to mount a response, but it will not make us sick the next time we encounter that pathogen. In short, every day that we spend being healthy is all thanks to our Immune System Specifications and Components.