Transcript Pathogen
Pathogen 病原體 Introduction Pathogen means some substance that will cause infectious disease of man.Their success depends large amount of it. Pathogens are include: Viruses(病毒) Bacteria(細菌) Fungi(真菌) Protozoa(原生動物) Transmission Inhalation of droplets Direct contact with infected area Ingestion of food or water contaminated by the excreta of host Trough contamination of skin wounds By vectors such as insect and rodents By wind Question Which group of pathogen is the sars belongs to?And what is it called. It belongs to viruses.It is called corona virus. Viral disease Virus can replicate itself Virus will cause biological malfunctioning of cells and organs E.g. Smallpox, Measles,Influenza, AIDS, Hepatitis B —HIV —Sars Question What is the different between cold and influenza? Influenza will get fever and cough.Human will feel tire and pain.It is more serious then cold. Bacterial disease Bacteria cause disease directly destroying the body tissues Releasing toxins from their cell to cause harm Cause food poisoning E.g. Tuberculosis —Cocci —Spirilli Fungal disease Fungal disease can be divided into three groups Infection I.e.athlete’s foot ,ringworm Food poisoning I.e.poisonous mushroom Allergic reaction I.e.Hay fever, Farmer’s lung —Yeast —Toadstool Protozoan disease Include amoebic dysentery and malaria It can live anywhere that contain moisture content. But they still affected by temperature,pH value,amount of oxygen, 變形蟲 (Amoeba) 草履蟲 (Paramecium) Pathogen of plants Affect the growth of plant Infect the seed and transmit to another seed Transmission: Irrigation, by wind, by seed Example: Pythium aphanidermatum (根腐病) Rhizoctonia solani (立枯絲核菌) Pathogen of domesticated animals Hand foot mouth disease Transmission: Skin wounds, Excreta Latent period: 3~7days At first,the symptom of this disease just like catch cold.then it seems red swelling and swollen appear on the skin. Pathogen in Hong Kong: Norwalk Virus(諾沃克病毒) Strong contagious disease(高傳染性病) Transmit by Inhalation of droplets,Ingestion of food or water contaminated by the excreta of host. Symptom: diarrhea, fever, vomit What can do: drank more water, keep fresh air, cook the food completely, wash your before eat and after go to toilet. Question How do our body defend prevent pathogen from entry into our body. 細菌小子 > Body Defend Phagocytes It engulf the pathogen and destroy them. After phagocytosis, the phagocytes are also be destroyed. The mixture remain is known as pus(膿) Blood Clotting Fibrin and platelets are that part in it. Fibrin act like a net,catching blood cells and sealing off the wound. ~End~