Effects Viruses have on Humans

Match The Vocabulary

1)Pathogens: 2)Mucus: 3)Primary line of defence:4)Immune System:5)Phagocytises:.6)Lymphocyte: 7)Antibodies: 8)Interferon:9)Interleukins:10)Active immunity: 11)Virulent: 12)Passive immunity:

. a) disease causing organism b) the natural protection provided by the skinc) cellular process of engulfing substances that are too larged) Immunity from infection or diseasee) harmful nature.f) Protein produced by certain white blood cells due to response of infectiong) Y-shaped proteinh) tissues and organs that protect organisms from infectioni) watery product from cells used to lubricate surfacesj) Protein produced by certain white blood cells to help fight viral infection k) Only possible following infection of vaccination. l) Type of white blood cell that becomes specialized

More information on Viruses

http://www.ucmp.berkeley.edu/alllife/virus.html

Viruses and their affect on Humans By attaching itself to a

host cell, the virus may either kill or alter the cell’s functions. When the cell dies, new types of viruses are released, and they infect other cells. This is how viruses cause disease. Generally, viruses will only infect one type of cell. For example, the cold virus will only infect cells of the upper respiratory tract.

Viruses can be transmitted in numerous ways, such as through contact with an infected person, swallowing, inhalation, or unsafe sex. Factors such as poor hygiene and eating habits can increase your risk of contracting a viral infection.

The external barriers, such as the skin and mucous membranes, are the first line of defense. The body’s immune defenses are triggered when the virus enters the body, and white blood cells (lymphocytes and monocytes) begin to attack and destroy the virus.

This type of general protection is referred to as innate or natural immunity.

Defence System

the first set of cells — neutrophils, monocytes (which generate the mighty macrophages), eosinophils, and basophiles — serves as an instant, on-demand immunological defence system. Always on the ready, these cells wage a generalized campaign of destruction against any pathogens that might come their way while signaling other cells of the presence of intruders.

The on-the-ready cells function in multiple ways. Neutrophils "eat" pathogens and send off distress signals. Monocytes are triggered to turn into pathogen-eating macrophages. Eosinophils attack parasites, and basophils contain granules filled with histamine and other compounds related to allergies. The second set of cells — the lymphocytes — is slower to react.

Natural Defence We know that the human body has natural defences against the virus infection. The presence of an invading virus causes specific protein molecules, called antibodies, to be generated. These antibodies, circulating in the blood, attach themselves to the invading viruses they meet.If enough of the antibodies are generated in time, the virus particles are completely surrounded and inactivated. They can no longer attach themselves to cells and can no longer multiply.

The human who successfully suppresses a virus infection in ties that way may show no symptoms of the infection and may not know that he has been infected. But thereafter he carries in his blood some antibodies which will help to suppress the next infection by a similar virus.In countries where a particular virus disease is endemic many of the inhabitants will be immunized in this natural way, while other inhabitants and also travelers from other countries may be infected, and quickly show symptoms of the disease if they come into contact with it. Their natural generation of the specific antibody may be too slow to suppress the initial infection. So, if the disease is serious, those not naturally immunized will need to be immunized artificially.