Body Defense Mechanism
Body Defense Mechanism: The defense mechanism of the human body is a gift, which is provided to human beings by nature. The power of our body, which fights against various disease-producing germs or agents, is called a defensive mechanism.
The defensive mechanism depends upon various factors. These factors can be divided into two parts to have a vivid and clear understanding.
- Common factors
- Special factors
1. Common Factors.
The following factors are included in common factors:
1. The health of the individual– The health of an individual is a vital factor. We are well aware if an individual has good health, his/her body protects itself automatically against various diseases. But if an individual does not have good health, he/she may be attacked by the germs of various diseases, and automatically he/she may fall ill. For keeping good health, an individual should take a nutritious and balanced diet. It means that we should take fats, proteins, carbohydrates, vitamins, minerals, and water according to our requirements for keeping us in a good state of health.
2. Skin– The skin of our body also protects us against harmful germs of various diseases. If we get abrasions or cuts on our skin, the harmful germs of any disease can penetrate through these cuts or abrasions in our body and can cause disease to the person. So, a cut or an abrasion should not be left open. If the bandage is not available, it may be covered by a clean piece of cloth.
3. Presence of Bacteria in our Body– Various types of bacteria live on and inside our bodies. These bacteria reside in our bodies permanently. In fact, these bacteria are beneficial for us, hence they can be called our friends. They do not cause any disease. By their presence, they do not allow disease-causing germs or organisms to settle in those places. In the same way, many microorganisms, which remain present in human saliva, secrete chemical substances, which do not allow diphtheria-causing organisms to grow in the mouth cavity.
5. Secretion of Fluid– Many organs of Our body secrete different kinds of fluids. These fluids kill the germs of various diseases. For example, gastric juice is secreted by our intestines, which is acidic in nature. It kills the fl germs of various diseases, which enter our body through food and drinks. Similarly, lysozyme, a fluid secreted by our eve glands, saves us from infection of the eyes because it kills the germs, which go inside our eyes through contact or from the environment.
5. Reflex Actions of our Body– Reflex actions of our body are those actions that are automatic or work involuntarily. These reflex actions protect our body from infections of various diseases. Such reflex actions are sneezing, coughing and vomiting, etc. Whenever any harmful substance enters our nose or throat, the reflex actions react spontaneously, and consequently, we start sneezing, coughing, or vomiting automatically. It means that our reflex actions try to expel that harmful substance from the body.
6. Fever– Fever is also a vital constituent of the defensive mechanism of the human body. Hypothalamus, which is situated in the brain, regulates or controls the temperature of our body. When germs of any disease, after entering the body, release toxic products and these products reach the brain through blood, the hypothalamus starts increasing the temperature of the body. We call it fever. The germs of the disease get killed, when the temperature of the body increases. During the process of fever, blood circulates at a faster rate. This complete process helps in expelling toxic products from all the tissues of the body through urine and sweat. So, fever should not be suppressed at the first stage by taking medicines.
7. White Blood Cells– If the number of White Blood Cells is sufficient in our body we may not fall prey to disease normally. These cells strengthen the defense mechanism of the body. Whenever the need arises, these cells come out from blood vessels and reach the affected site. These cells engulf and kill the germs of the disease.
8. Healthy Blood– Some substances such as leukins, beta lysin, lysozyme, etc., are e found in healthy blood, which kill the germs of disease and stop their growth. In this way, the defensive mechanism of the human body also depends upon healthy blood.
Body Defense Mechanism
2. Special Factors
We are living in an environment, which is full of various types of germs. Many types of these germs infect us and thus we fall prey to various diseases. But it has been observed that all individuals do not fall prey to these diseases. In fact, it is due to a special power, which remains present in our body to fight against disease-causing germs.
This special power of our body is called Immunity Power. This power protects us from the germs of various diseases. Every individual has a different level of Immunity Power. The individuals, who rarely get ill, have a higher level of Immunity Power than the individuals, who usually fall prey to diseases.
Immunity Power can be divided into two categories, which are described below:
- Natural or Innate Immunity Power
- Artificial or Acquired Immunity Power
1. Natural or Innate Immunity Power– Natural or innate immunity power depends upon the heredity or biological characteristics of the individual. It means Innate Immunity Power is related to an individual’s caste, race, and other biological traits. For example. Negros have immunity power against yellow fever due to race as well as heredity. In this way, we see that all individuals living in the same place do not fall prey to communicable diseases.
2. Artificial or Acquired Immunity Power– We acquire artificial immunity power in our lifetime. This power can be divided into the following types:
- Active Immunity Power
- Passive Immunity Power
1. Active Immunity Power- Active immunity power is that power, is acquired by the efforts of the tissues of the body. For example, after the attack of smallpox, the tissues produce antibodies so that the person may not be affected by the germs of smallpox again. It means that the same person will not fall prey to smallpox again.
2. Passive Immunity Power– Passive immunity power can be obtained by injecting a few germs of any disease into the body of an animal at some intervals. Through this process, the antibodies are manufactured against that disease in that animal. After that, the serum is taken from that animal and injected into the body of the person.
This serum increases the immunity power of that person. In this process, the tissues of the person do not perform any work. Such a type of immunity power is very light but permanent. For example, anti-tetanus serum and anti-Diptheria serum, etc., are vaccinated to increase the immunity power in a person against these diseases.
