Transcript Viruses PPT
You are to write a narrative about a patient that has been infected with the Ebola Virus. Tell their story…. Include: • How was the virus contracted? • Where (location) was the virus contracted? • How did the patient find out they were infected? • How was the diagnosis determined? • What are the treatment options? • How was care given to the patient? Viruses Lytic Cycle In the lytic cycle, the virus takes over the hosts DNA and grows its own. It grows its own DNA and new viruses. The virus uses the energy of the host cell. When it is full, the host cell explodes and releases new viruses. Lytic Cycle http://www.youtube.com/watch?v=wLoslN6d3Ec The Lytic Cycle A provirus is a DNA virus that has been inserted into a host cell chromosome. A retrovirus injects the enzyme, reverse transcriptase into the cell to copy viral RNA into DNA. HIV is a retrovirus injecting the enzyme, reverse transcriptase into the cell to copy viral RNA into DNA. Viruses are host specific – a protein on the surface of the virus has a shape that matches a molecule in the plasma membrane of its host, allowing the virus to lock onto the host cell. HIV doesn’t target just any cell, it goes right for the cells that want to kill it. “Helper" T cells are HIV's primary target. These cells help direct the immune system's response to various pathogens. HIV undermines the body's ability to protect against disease by depleting T cells thus destroying the immune system. The virus can infect 10 billion cells a day, yet only 1.8 billion can be replaced daily. After many years of a constant battle, the body has insufficient numbers of T-Cells to mount an immune response against infections. At the point when the body is unable to fight off infections, a person is said to have the disease AIDS. It is not the virus or the disease that ultimately kills a person; it is the inability to fight off something as minor as the common cold. The vaccine is administered. It contains weakened or dead forms of the disease 1.The immune system identifies these foreign substances (viruses and bacteria), also known as antigens. 2.Once antigens are identified, the immune system develops proteins that circulate in the blood. These proteins are called antibodies. They fight the infection by killing the antigens. Antibodies are made by white blood cells called lymphocytes, also known as B cells. The main purpose of B cells is to create antibodies to fight infection. 3.The body stockpiles these antibodies so they are available to fight off the disease if exposed later on. Unfortunately, antibodies are disease-specific, so previously acquired chickenpox antibodies will be useless if faced with other diseases. • Jenner was operating on the now widely accepted principle that once a person catches a certain disease, he or she is immune to it for the rest of their life. For example, once you've had the chickenpox, it's extremely unlikely that you'll ever catch it again. This is because your body, when exposed again, will recognize the disease and fight it off. The beauty of vaccines is that they help the body develop disease-fighting abilities without making you sick. Vaccines accomplish this amazing feat by tricking the body into believing it already has the full-blown disease. Here are the steps in this process, known as the "immune response": • • • • • • • • • • • • • • • • • • • Vaccine-preventable Diseases Anthrax Cervical Cancer Diphtheria Hepatitis A Hepatitis B Haemophilus influenzae type b Human Papillomavirus Influenza Japanese encephalitis Lyme disease Measles Meningococcal Monkey pox Mumps Pertussis Pneumococcal Polio Rabies Rotavirus Rubella Shingles Smallpox Tetanus Typhoid Tuberculosis Varicella Yellow Fever Source: CDC v