Presentation on theme: "By: Martin Naranjo and Juan Jacobo Gachan. An agent of disease or in other words a disease producer. The term pathogen most commonly refers to an."— Presentation transcript:
An agent of disease or in other words a disease producer. The term pathogen most commonly refers to an organism or a virus that causes a disease. These include bacteria (such as staph), viruses (such as HIV), and fungi (such as yeast). Less commonly, pathogen refers to a noninfectious agent of disease such as a chemical.
Antibiotics are drugs produced by microorganisms which kill or slow or control the growth of other microorganisms like bacteria by blocking specific metabolic pathways within the cell. Since bacteria are so different to human cells, antibiotics can be taken by humans to kill bacteria without harming the human cells. Antibiotics block metabolic pathways of bacteria, inhibiting cell wall formation and protein synthesis, resulting in the death of foreign bacteria. Viruses on the other hand are different as they do not carry out many metabolic processes themselves. Viruses are not alive and instead they rely and utilize the organisms host cells to replicate which are not targeted by antibiotics. Therefore viruses cannot be treated with antibiotics as it is impossible to harm the virus without harming the human cells.
Skin and mucous membranes act as barriers against pathogens. The skin and mucous membranes form a barrier that prevents most pathogens from entering the body. The other layers of the skin are tough and form a physical barrier. These dry, keratinized layers of skin discourage pathogen growth. The skin also produces a thin layer of acid and oils. Mucus contain an enzyme called lysozyme which kills bacteria.
Phagocytes are a type of leucocytes which ingest and destroy foreign matter through phagocytosis. They can easily move through the walls of blood capillaries and the place in which there is an infection. A phagocyte comes in contact with pathogen cells and does not recognize the glycoprotein structure on its cell wall. The pathogen is then ingested through endocytosis and plasma membrane forms around pathogen. Pathogen vacuole then binds with lysosome containing digestive enzymes which break down the pathogen. Large numbers of phagocytes form pus.
Antigens are macromolecules that elicit an immune response by lymphocytes. Antibodies are proteins secreted by plasma cells that bind to a particular antigen and mark it for elimination.
Antibodies are made by lymphocytes, which recognize an enormous number of antigens, but each individual cell recognizes only one type of antigen. Each lymphocyte puts some of the antibody that it makes into its cell surface with the antigen-combining site projecting outwards. When a pathogen enters the body, its antigens bind to the antibodies in the cell surface of one type of lymphocyte. The selected lymphocyte proliferates to give rise to a clone of identical cells bearing receptors for the selecting antigen. Some of the cells develop into short-lived plasma cells that secrete antibody specific for the antigen. Others develop into long-lived memory cells that can respond rapidly upon subsequent exposure to the same antigen.
HIV attacks T-cells which are part of the immune system that are important for the formation of Beta lymphocytes. The virus enters the T-Cells and replicates there. As reproduction increases, the cell breaks up and the virus RNA is spread to other T-cells. The virus keeps infecting and killing other T-cells, paralyzing the immune system. This enables other organisms usually kept under control by the immune system to be able to affect the body.
The basic cause of AIDS is that the HIV retro-virus develops further enough to change into AIDS. HIV doesn’t survive outside of the body and can’t easily pass through the skin.
Transmission involves the transfer of body fluids from an infected person to an uninfected one. Through small cuts or tears in the vagina, penis, mouth or intestine during vaginal, anal or oral sex. In traces of blood on a hypodermic needle that is shared by intravenous drug abusers. Across the placenta from a mother to a baby, or through cuts during childbirth or in milk during breast feeding. In transfused blood or with blood products such as Factor VIII used to treat hemophiliacs.
Friends and families suffer grief. Families become poorer if the individual with AIDS was the wage earner and is refused life insurance. Individuals infected with HIV may become stigmatized and not find partners, housing or employment. Sexual activity in a population may be reduced because of the fear of AIDS.