Exercise 2. Read and complete the sentences with appropriate words. Shields, direct, effective, retains, become unwell
Exercise 2. Read and complete the sentences with appropriate words. Shields, direct, effective, retains, become unwell, protection, hinder, microorganisms, defensive, divided. Our body possesses a formidable army that provides defense against various forms of threats. This personal military force is known as the immune system. Each day, we come across a vast number of bacteria, viruses, and other pathogens that can cause illnesses. Nevertheless, we do not fall ill on a daily basis. This is because of our immune system. The immune system can be broadly categorized into two parts - innate and adaptive immunity. Innate immunity serves as the body"s initial natural barrier against any intruders. Its primary aim is to _____
Magnitnyy_Lovec 54
и adaptive. The innate immune system provides general, non-specific protection against a wide range of pathogens. It acts as a first line of defense, quickly responding to any invading microorganisms.The innate immune system includes physical barriers, such as the skin and mucous membranes, which act as shields to prevent the entry of pathogens into the body. These barriers form a physical barrier and also secrete substances that can directly kill or inhibit the growth of microorganisms.
In addition to physical barriers, the innate immune system includes cells and molecules that play a role in the recognition and elimination of pathogens. One of the key cell types involved in the innate immune response is the phagocyte. Phagocytes are cells that engulf and destroy pathogens through a process called phagocytosis. They can recognize and eliminate a wide range of pathogens, including bacteria, viruses, and fungi.
The innate immune system also produces various molecules that help in the defense against pathogens. These molecules include antimicrobial peptides, which can directly kill microorganisms, and cytokines, which are signaling molecules that help coordinate the immune response.
While the innate immune system provides a rapid response to pathogens, it is not specific to particular pathogens. This is where the adaptive immune system comes into play. The adaptive immune system is a more specialized and targeted response, which develops over time as a result of exposure to specific pathogens.
The adaptive immune system relies on specialized cells called lymphocytes, which are responsible for recognizing and responding to specific pathogens. There are two main types of lymphocytes: B cells and T cells. B cells produce antibodies, which are proteins that can bind to specific pathogens and mark them for destruction. T cells, on the other hand, directly attack infected cells.
One of the key features of the adaptive immune response is memory. Once the immune system has encountered a specific pathogen, it "remembers" it and can mount a faster and more effective response upon re-exposure. This is why vaccination is such an important tool in preventing infectious diseases. Vaccines expose the immune system to harmless fragments or weakened forms of pathogens, enabling it to develop a memory response without causing the disease itself.
In summary, the immune system is a complex network of cells, molecules, and barriers that provides defense against pathogens. The innate immune system provides a non-specific, immediate response to a wide range of pathogens, while the adaptive immune system develops specific responses and memory upon exposure to particular pathogens. Together, they form our body"s formidable defense against illnesses.