The Transmission Of Pathogens Biology Essay

The Transmission Of Pathogens Biology EssayInfectious ailments atomic number 18 caused by the contagious disease of pathogens, which are microorganisms such as bacteria and viruses. Pathogens can be transmitted by direct arrive at crosswise and vertical transmittal and by indirect contact vehicle-borne transmission and vector-borne transmission.Pathogens are microorganisms that cause pathogenic disease. bacteria and viruses are the main pathogens.BacteriaSalm binglella bacteria cellBacteria come in many another(prenominal) shapes and sizes, scarce even the largest are plainly 10 micrometres long (10 millionths of a metre).Bacteria are documentation cells and, in favourable conditions, can multiply rapidly. Once inwardly the body, they release poisons or toxins that make us feel ill.VirusesHepatitis C virus. DNA are wrap in a protein coat.Transmission of pathogensMicroorganisms can be transmitted in two main ways direct contact and indirect contact. send off contactDir ect contact means that the disease-causing microbe is go throughed from one soul to another when their bodies touch in just about way.Vertical transmission happens when microorganisms pass from a mother to her unborn baby through the plapennya. German morbilli and HIV can pass this way.Horizontal transmission happens when microorganisms pass from one person to another by touching, kissing or sexual intercourse.Examples of horizontal transmissiontype of contactbacterial diseaseviral diseasetouchingbacterial gastroenteritischickenpoxkissingbacterial meningitisglandular fever, cold soressexual intercoursegonorrhoea, syphilisHIV, hepatitis BIndirect contactIndirect contact happens when microorganisms are carried to a person in some way, instead of by actual body to body contact.Vehicle-borne transmission involves an reject carrying the disease-causing microorganism.Examples of vehicle-bourne transmissionvehiclebacterial diseaseviral diseasedroplets in the airtuberculosis (TB)colds, fluwatercholerapolio precipitate objectstetanusHIVfoodSalmonella food poisoninghepatitis AVector-borne transmission involves an animal such as an insect. For example, malaria is transmitted by mosquitoes and plague by fleas.The first caper of defenceMost pathogens have to desex inside our body to spread infection. Once they are inside, the body provides ideal living conditions plenty of food, water and warmth. Standing in their way is our bodys immune musical arrangement the bodys co-ordinated response to the invading pathogens.The first line of defence is the bodys natural barriers. These entangle tegumentnasal hairs, mucus and ciliatearsThe skinCross-section of skinThe skin covers the whole body. It protects the body from physical scathe, microbe infection and dehydration. Its dry, unwarranted outer cells are difficult for microbes to penetrate, and the sebaceous glands produce oils which help turn thumbs down microbes.Nasal hairs, mucus and ciliaThe respiratory system (o r gaseous exchange tract) is saved in several ways. Nasal hairs keep out dust and larger microorganisms. Sticky mucus traps dust and microbes. These are then carried away by cilia, which are circumstantial hairs on the cells that line the gaseous exchange tract. snapTears, saliva and mucus contain an enzyme called lysozyme. This destroys microorganisms.The second line of defenceScabsIf microorganisms get into the body through a cut in the skin, the most cardinal thing is to quickly close the wound so more microorganisms cannot enter. A tell on does just this. The blood contains tiny structures called platelets, and a protein called fibrin. A scab is basically platelets stuck in a fibrin mesh. The animation shows how this works. sporting blood cellsAs a wound heals, nearby blood vessels widen to allow more blood to reach the area. This causes inflammation where the damaged area becomes swollen, hot and red. White blood cells called phagocytes move into the area, and destroy bact eria by engulfing and digesting them.The third line of defencePathogens contain certain chemicals that are foreign to the body and are called antigens. White blood cells called lymphocytes carry a specific type of antibody a protein that has a chemical fit to a certain antigen. When a lymphocyte with the appropriate antibody meets a dangerous foreign body (pathogen containing antigen), the lymphocyte reproduces quickly, and makes many copies of the antibody that neutralises the pathogen.Antibodies neutralise pathogens in a number of waysThey bind to pathogens and damage or destroy them.They coat pathogens, clumping them together so that they are well ingested by phagocytes.They bind to the pathogens and release chemical signals to attract more phagocytes.Lymphocytes may also release antitoxins that stick to the appropriate toxin and stop it damaging the body. terabitTuberculosis, or TB for short, is a disease caused by a bacterium called Mycobacterium tuberculosis. The microorga nisms are spread through the air in tiny droplets when an septic person sneezes or coughs. Most people who are infected do not show any symptoms. About 10 per cent of people who are infected give go on to pose symptoms, which includeshortness of breathcoughingweight loss fatiguefeverdeath (in about 50 per cent of cases)Only infected people who show symptoms of TB can spread the microorganisms to other people. streak and control of TB (Higher Tier)The BCG (Bacillus Calmette-Gurin) vaccination protects about 75 per cent of light people from becoming infected.Antiobiotics are drugs that kill bacteria or observe them from reproducing. Infected people who do not show any symptoms of TB are usually given a course of one antibiotic, but infected people who are showing symptoms of TB need a course of several antibiotics at once. This is to reduce the chance that strains of antibiotic-resistant bacteria will emerge.http//www.bbc.co.uk/schools/gcsebitesize/science/edexcel/health/defendin gagainstinfectionrev5.shtml