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Flashcards by Gabbie waite , updated more than 1 year ago
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Created by Gabbie waite
almost 8 years ago
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| Question | Answer |
| 9.4 The search for better health | *Discuss the difficulties of defining the terms 'health' and 'disease': Health- Being active and free from pain; feeling happy and thinking clearly. - 'Health' is hard to define as it has many components which are based on opinions. 'Disease'- Refers to a state of impaired functioning or poor health. This is hard to define as it depends on an individuals normal level of functioning and what they expect their quality of life to be. |
| * Outline how the function of genes, mitosis, cell differentiation and specialisation assist in the maintenance of health: - The function of genes; To ensure that the correct proteins are produced in a cell to enable all cellular processes to continue. If genes are faulty, and the polypeptides and proteins they make are also faulty, then the cell processes or structure may be abnormal and can lead to disease. | The function of mitosis; Mitosis (cell division resulting in two daughter cells) enables genetic material to be copied correctly when new cells are formed. A cell has DNA repair genes which repairs and maintains the DNA. Cancer is the disruption of the cycle of cell replication and division. Uncontrolled growth leads to the formation of tumours. |
| The functioning of cell differentiation and specialisation;CELL DIFFERENTIATION AND SPECIALISATION: Cell differentiation is when cells mature and take on different structural features so that they're structurally suited to perform a specific function in the body. E.g. RBC's contain HB to transport oxygen around the body. - Cell specialization is when specific genes in cells are switched 'on' or 'off' in order to perform a specific function in the body. E.g. in RBC's, the gene for HB is switched on, allowing the RBC to perform its specific function of oxygen transport. | - Cell differentiation is important because without this, there would be no specialized cells produced to maintain health such as occurs during the increased production of lymphocytes in an infection. - Cell differentiation and specialization enable cells to carry out complex functions by working together in a controlled way, thus maintaining an organism's health. - If differentiation and specialization didn't occur, processes in the body wouldn't be coordinated as the cells wouldn't be able to function effectively. |
| If differentiation and specialization didn't occur, processes in the body wouldn't be coordinated as the cells wouldn't be able to function effectively. * Distinguish between infectious ad non-* Distinguish between infectious ad non- disease: Infectious diseases are caused by a pathogen that enters the body and can be transferred from person to person. -A Non-infectious disease is not caused by a pathogen or organism carrying disease. - These diseases are caused instead from genetic, lifestyle or the environment. | |
| *Explain why cleanliness in food, water and personal hygiene practises assist in control of disease: -As infectious diseases are caused by pathogens, controlling disease should focus on preventing pathogens from entering the body. This involves reducing exposure to pathogens, preventing pathogens from multiplying in food, water or the body, and preventing transmission of the pathogen between people. | * Identify the conditions under which an organism is described as a pathogen: -Something is a pathogen if it's an organism or infective agent that lives in/on another organism and CAUSES DISEASE. To do this, it needs the right conditions to multiply and be transmitted (escape from one host to another and survive transmission). |
| * Gather, process and analyse information from secondary sources to describe ways in which drinking water can be treated and use available evidence to explain how these methods reduce the risk of infection from pathogens: -Coagulation - Coagulants are added to the water and cause the binding together of fine particles such as clay and silt. It reduces the risk of infection because Microbes become trapped in the particles. Filtration is The passage of water through a bed of fine particles e.g. sand. It reduces the risk of infection as it Removes fine, suspended solids that contain microbes and larger microorganisms. | *Describe the contribution of Pasteur and Koch to our understanding of infectious diseases: -Louis Pasteur: Discovered that most infectious diseases are caused by micro-organisms, or germs- "Germ theory of disease". This was discovered through his research on fermentation of wine. He discovered that the germs spoiling the wine could be killed by hating the wine to 55 degrees. This method is now applied to milk and beer=pasteurisation. |
| Robert Koch: Studied the cause of the disease anthrax. -He succeeded in isolating the bacterium from the blood of the dying animals. - He found out that the blood of animals with the disease always contained the micro-organisms and also that if it were injected into a healthy animal it would also cause the disease. | Koch's postulates; 1) The micro-organism must be present in every host with the disease. 2) Must be isolated and then grown in a pure culture. 3) Affect another host with the microorganism which must develop the same symptoms. 4) That specific micro-organism must be isolated and identified as the same species as originally cultured. |
| * Distinguish between - Prions: Are infectious agents that cause brain disease in mammals. -They are proteins that have been altered from their normal shape. -characteristics include; dementia, loss of motor control. -In animals; Mad cow in cattle. -Viruses: -Found in all types of cells - Only reproduce inside another cell, called a host cell. - Once inside the nuclear material from the virus causes the cytoplasm of the host cell to produce new viruses. E.g Small pox, measles, warts, influenza. | -Bacteria: - Are the prokaryotic (No distinct nucleus with a membrane) cells. - Bacteria lives freely, but some are parasites, some are pathogens of animals and plants which cause disease. E.g Tetanus, pneumonia, chlamydia -Protozoans: -Are single celled animal like eukaryotic (organised nucleus) organisms- e.g malaria -Fungi: - Large group of eukaryotic organisms that include micro-organisms such as yeast, moulds, mushroom. Heterotrophic-get food from plants and animals NOT photosynthesis. e,g ringworm |
| *Explain why cleanliness in food and water and personal hygiene practises assist in the control of disease: | |
| * Identify the role of antibiotics in the management of infectious disease: | - Antibiotics are chemical substances which destroy bacteria or inhibit their growth. They target the bacteria without destroying the host. They are not effective against viruses. -Antibiotic resistance; -The first antibiotic was penicillin. Penicillin contains a special ring-shaped molecule in its structure which gives is bactericidal (A substance which kills bacteria) properties. - An example where bacteria grew resistant- 'Penicillin and s'aureus' How? - The s'aureus possesses different genes which vary to that of its offspring which enables it to survive. |
| * One named infectious disease: -MALARIA: - Caused by the protozoan parasites of the genus plasmodium - Transmitted by the female mosquito - The malarial parasite was first identified in the stomach of an anopheles mosquito by Ronald Ross. - The life cycle of the malarial parasite: 1) The infection is a result of a bite from a female mosquito that is carrying the parasite. 2) When the female mosquito pushes its feeding tube through the human skin, it injects its saliva which contains a anticoagulant(stops the blood from clotting) so the mosquito can keep consuming the blood. 3) If the mosquito is infected the parasites are released into the human blood stream. | 4) These sporozoites then enter the liver cells where they grow and divide repeatedly. 5) They are all then released into the blood plasma where they invade the red blood cells. 6) The red blood cells then burst and release more merozoites, causing fever and regular fevers and chills. *Identify defence barriers to prevent entry of pathogens in humans: -SKIN: - Forms a tough outer barriers covering the body. - The skin has harmless bacteria living as 'commensals' (where one benefits and one doesn't harm the other). These stop pathogens multiplying. -If the skin is broken the blot clotting mechanism quickly forms a seal around the wound to prevent the entry of pathogens. |
| - MUCOUS MEMBRANES: - Line the digestive, respiratory, reproductive and urinary tracts with a thick mucus. -It allows for the change of substances whilst also protecting against invasion. - The presence of IGA Antibodies in mucus reacts with the pathogens preventing their invasion. -CILIA: -Are minute hairs that project from the cells lining the respiratory surfaces of the nose, trachea and bronchial tubes. - The cilia sweep the mucus along so that any particles breathed in and trapped in the mucus can be transported out. | - CHEMICAL BARRIERS: - Chemical barriers are provided by conditions which make the surface inhospitable for pathogens. E.g Stomach acid. -OTHER SECRETIONS: E.g Harmless microorganisms in the vagina which act on the cells which have been shed from the walls of the vagina to create an acidic environment which stop the growth of bacteria or fungi. e.g 2- Urine which is a sterile acid fluid which flushes the ureters, bladder and urethra which helps prevent the growth of microorganisms. |
| *Identify antigens as molecules that trigger an immune response: - The body's immune response is it's reaction to invasion of foreign materials. These substances are identified as foreign by the body which then responds by trying to destroy them. Substances that trigger this reaction are known as antigens. | *Explain why organ transplants should trigger an immune response: -Transplants are used to treat people whose tissues are diseased such as; kidneys, heart, lungs and bone marrow. - However, an introduced organ contains antigens that are recognised as foreign to the patient which triggers the immune response and the production of antibodies which attack and possibly destroy the new tissue. |
| * Identify defence adaptations, including; 1) Inflammation response- When any body tissue is damaged, the are becomes red, hot, swollen and painful. The blood circulation to that part is increased and the blood vessels dilate. This helps confine the pathogen while white blood cells attack it and destroy it. 2) Phagocytosis:- Are white blood cells that can actively move from the blood tissues, where they ingest and destroy an foreign materials. - Phagocyte is called Neutrophils= During acute inflammation (Lasting hours our days) - Phagocyte is called macrophages= During chronic inflammation( Weeks or months) | 3) Lymph system: Lymphocytes are white blood cells that become active in chronic inflammation. - The lymphatic system in the body contains lymph vessels that form a drainage system. If there is an infection in the tissues the foreign particles, get moved along with the tissue fluid into the lymph vessels. Along the vessels are lymph nodes. Here the waste particles are filtered and foreign particles are destroyed by macrophages. This is why swollen lymph nodes are good indicators of infection. |
| Cell death to seal of pathogens: - When the body is unable to neutralise an antigen, a particular type of chronic inflammation involving both macrophages and lymphocytes may occur. *Identify the components of the immune response: 1) Antibodies (immunoglobins) : Are proteins that the body produces when it detects specific antigens. Different antigens stimulate the production of different antibodies. Join with antigens, causing them to clump together to form an antibody-antigen complex. | 2) T cells: Special kind of lymphocyte - Produced in bone marrow - Mature in the thymus gland - Remain inactive in the blood until they come into contact with an antigen. - The antigen binds to the T-cell activating it to multiply (making clones). |
| B-cells: (Plasma cells) - Control the blood response where they are activated when antigens enter the blood stream. - Once activated they clone themselves and then differentiate into the plasma cells that send antibodies into the blood or into memory cells. | *Evaluate the effectiveness of vaccination in preventing the spread and occurrence of small pox: -Small pox is a viral disease -Caused by the variola virus - Characteristics; rash of blisters or pustules on the skin which eventually dry up and leave scars. - Can be deadly if the virus attacks the circulatory system, bone marrow or respiratory system. - The WHO had a worldwide campaign of immunisation and by 1979 the last case was detected. - Symptoms include; fever, headache, muscular aches, red rash on face, blisters/pustules. |
| - Edward jenner hypothesised that milkmaids hardly got the disease and that their prior infection with the relatively harmless disease known as 'cowpox' may have protected them. -Using similar techniques to Jenner, researchers devised an effective small pox vaccine based on the 'vaccina virus'. - Within 12 years smallpox was eradicated. | * Describe and explain the immune response in the human body in terms of; - Interaction between B and T lymphocytes: When an antigen enters the body it travels to the lymphoid tissue where it is swallowed and processed by a macrophage. The macrophage then shows parts of the antigen on its outer membrane which are then recognised by T and B cells. -The mechanisms that allow interaction between B and T cells: They can interact as they are close together and regulated by cytokines. Cytokines start the immune response by signalling other cells. |
| - The range of T lymphocyte types and the difference in their roles: - Cytotoxic T cells produce toxic substances that destroy cells that have been invaded by a pathogen. - Helper T cells help B cells divide rapidly. - Suppressor T cells turn off the immune response and suppress the production of antibodies when they are not needed. - Memory T cells recognise the antigen if it is re-introduced, providing long-term immunity. | *Outline the way in which vaccinations prevent infection: Vaccination/immunisation is the process of making people resistant to infection caused by a pathogen. - A vaccine contains an agent that resembles a disease-causing microorganism, and is often made from weakened or killed forms of the microbe, or its toxins. The agent stimulates the body's immune system to recognize the agent as foreign, destroy it, and "remember" it, so that the immune system can more easily recognize and destroy any of these microorganisms that it later encounters. |
| *Outline the reasons for the suppression of the immune response in organ transplant patients: - Is necessary to prevent rejection of new organs. - Because the blood drains from transplanted organs into the patients circulation the body recognises it as foreign tissue and produces antibodies in response. - Rejection is stopped by matching the transplanted tissues proteins to the recipients proteins as closely as possible. | b |
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