Antibiotic resistance and overuse of vaccines has contributed to the increased incidence of emerging diseases and resistance and their controls and treatments.
Infectious diseases are caused by pathogens or organisms such as viruses, bacteria, fungi and parasites. The human immune system is the last line of defense against viruses and bacteria that enter the body. To fight off infectious diseases and protect the body, the immune system attacks organisms and substances that invade body systems. The immune system is an organization of tissues, cells, and organs. This network provides a sufficient shield against diseases for the human body. In most cases the immune system prevents infections …show more content…
The term is most commonly used for pathogens that distress the regular physiology of a multicellular plant or animal. However, pathogens can contaminate unicellar organisms from all of the biological kingdoms. Pathogens that come in the form of bacteria are microscopic organisms. They vary in all shapes and sizes and can only grow to approximately 10cm long. In suitable conditions, the bacteria can multiply very quickly. Once the pathogens are inside the body, they can let out toxins or poisons that cause the human body to feel ill. Diseases caused by bacteria include; whooping cough, typhoid, cholera and food poisoning.
Pathogens can also be types of viruses. Viruses are much smaller than bacteria and are among some of the smallest known organisms. They contain a fragment of genetic material inside a protective protein coat. Viruses can only reproduce when inside a host cell, they damage the cell when they do this. Once a virus has entered a cell, it has the power to take over and make hundreds of copies of itself. Eventually the copies of the virus fill the whole host cell, causing it to burst open. The viruses then bleed out into the bloodstream or by …show more content…
To help destroy pathogens from the body, white blood cells ingest them which stops them from harming the host. The white blood cells can produce antibodies to eradicate the pathogens and can also release antitoxins to neutralize toxin levels. There are many different types of white blood cells, all with different functions but can be sorted into two main groups; phagocytes and lymphocytes. A Phagocyte can easily pass through the walls of the blood vessel and into the surrounding tissue to move towards the pathogens. The phagocytes can either ingest and absorb the pathogens or release an enzyme to destroy them. Pathogens contain chemicals that are unknown or foreign to the body called