Better Health Dot Point (hsc Biology) 5e81h

SYLLABUS NOTES… 1. What is a healthy organism? SYLLABUS 1.discuss the difficulties of defining the ‘health’ and ‘disease’

2.outline how the function of genes, mitosis, cell differentiation and specialisation assist in the maintenance of health

a.use available evidence to analyse the links between gene expression and maintenance and repair of body tissues

STUDY NOTES Disease: Any condition that interferes with normal bodily functions e.g Cancer, chicken pox, cut finger. Health: A state of physical, social and mental wellbeing. This is not just the absence of disease. It can vary with age, expectations, culture and susceptibility. Is a subjective judgement. Difficulties: have different social and scientific meanings. It is possible for a person to be healthy and to have a disease at the same time e.g a cancer patient in remission. Genes control protein synthesis, making the correct proteins for growth and repair. Genes also produce the correct enzymes, which control all living processes. Mitosis: New genetically correct cells allow for growth and repair. Genetically incorrect can lead to cancers and death. Cell differentiation = cell specialisation. Undifferentiated cells can form tumours. Many cells specialize to maintain health e.g blood cells produce antibodies. Cystic Fibrosis is due to a faulty gene causing the wrong protein to be made. Gene expression is the “switching on” of a segment of DNA to produce a polypeptide. Many genes are switched “on” at various times during life and then switched “off” at other times resulting in maintenance of health e.g those genes responsible for menstruation and menopause.

2. Over 3000 years ago the Chinese and Hebrews were advocating cleanliness in food, water and personal hygiene SYLLABUS STUDY NOTES 1.distinguish between infectious and non-infectious disease Infectious diseases are caused by a pathogen(bacteria, virus, fungi) eg pneumonia, TB, Ebola, Chicken pox(Infectious AND Contagious) Malaria( Infectious, not contagious). Non infectious diseases do not involve a pathogen and may be genetic, environmental or nutritional. Scurvey, Downs Syndrome and Skin cancer. 2.explain why cleanliness in food, water and personal hygiene practices assist in control of disease Most pathogens (disease causing organism) enter through body openings. Intake of food and water provides easy access to these organisms. Measures

Treatment Filtering Chlorine and Ammonia Boiling Fluoride

Result Removes large particles Kills pathogens Kills pathogens Reduce tooth decay

such as personal hygiene, Govt legislation, proper waste disposal can minimise these risks. 3.identify the conditions under which an organism is described as a pathogen Pathogen = disease causing organism. Can be microscopic( bacteria, viruses and fungi) or macroscopic( tapeworms). They can live inside the body(virus) or outside ( fungus causing ringworm). They require the right conditions to multiply. Usually, warm, dark and moist. a.identify data sources, plan and choose equipment or resources to perform a firsthand investigation to identify microbes in food or in water AGAR PLATES The purpose of this prac is to highlight the huge amount of pathogens surrounding us. b. 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

3. During the second half of the nineteenth century, the work of Pasteur and Koch and other scientists stimulated the search for microbes as causes of disease SYLLABUS STUDY NOTES 1.describe the contribution of Pasteur: Pasteur and Koch to our  Disproved Spontaneous Generation theory with understanding of infectious famous swan necked flask experiment. diseases  Proposed The Germ Theory of Disease stating that most infectious diseases are caused by micro-organisms.  He showed the French wine industry that heating wine to 55oc destroys the microorganisms causing it to rot.  This process(Pasteurisation) is now applied to milk and beer. Founded the process of vaccination :  Inoculated 25 sheep with a weakened version of Anthrax bacteria  Then injected this group and another 25( the control group) with anthrax  The 25 inoculated sheep survived

2. distinguish between:  prions  viruses  bacteria  protozoans  fungi  macro-parasites and name one example of a disease caused by each type of pathogen

Robert Koch Also worked with anthrax. Isolated and identified the anthrax bacilli Ultimately developed Koch’s Postulates which are four criteria designed to establish a causal relationship between a causative microbe and a disease:  The microorganism must be found in abundance in all organisms suffering from the disease, but should not be found in healthy organisms  The microorganism must be isolated from a diseased organism and grown in pure culture.  The cultured microorganism should cause disease when introduced into a healthy organism.  The microorganism must be re-isolated from the inoculated, diseased experimental host and identified as being identical to the original specific causative agent.  Koch also developed methods for fixing and staining specimens onto slides. They paved the way for the study of microorganisms PATHOGEN DESCRIPTION DISEASE PRION Defective form of Mad cow protein, infectious CJD:Creutzfeldand inherited. Jacob Disease VIRUS Technically not Herpes, Hepatitis, living. AIDS, Plant DNA and RNA Mosaic virus surrounded by a protein coat. Can only reproduce inside the host cell. BACTERIA Prokaryotic single Tuberculosis, cells. Secrete Syphilis, ear toxins. infections PROTOZOAN Eukaryotic single Malaria, Diarrhoea cells. FUNGI Eukaryotic, Tinea, heterotrophic. Candida(Thrush)

3.identify the role of antibiotics in the management of infectious disease

Some are single Ringworm cells others are long branching threads. MACRO Multicellular Ticks, fleas, lice, PARASITE Eukaryotic. worms, aphids. Discovered by Alexander Flemming in 1928. However, he didn’t see the applications. An Australian, Florey, could see the applications and began the production of antibiotics( Penicillin from mould) to fight bacterial infections. This had a massive impact on world health, but only addressed bacterial infections.

a. perform an investigation to model Pasteur’s experiment to identify the role of microbes in decay

b. gather and process information to trace the historical development of our understanding of the cause and prevention of malaria

c. identify data sources, gather process and analyse information from secondary sources to describe one named infectious disease in of its: – cause – transmission – host response – major symptoms – treatment – prevention(personal) – control(government)

Originally thought to be caused by the foul gases that arise from marshes and swamps. In the early 1800’s it was suggested that it was caused by a microorganism. Quinine was then introduced as a preventative. The protozoan, Plasmodium was first identified in 1884. In 1897 the mosquito was identified as the vector. Cause: A single cell protozoan(eukaryotic) named Plasmodium Transmission: The female Anopheles mosquito Host response: Large quantities of the Plasmodium trigger a huge immune response resulting in macrophages and other immune cells destroying parasites by phagocytosis and by the production of toxins. The high levels of these toxins however, are responsible for the intense fever associated with malaria which in itself is harmful. Major Symptoms: Fever, sweating, convulsions, coma and death. Treatment: Antimalarial drugs such as Quinine Prevention: Neck to ankle clothing, Aero guard, mosquito netting at night and preventative medicines. Control: Draining of swamps, spraying of insecticides and oil over swamp areas(ecologically unsound). Biological control with the introduction of larvae

d. process information from secondary sources to discuss problems relating to antibiotic resistance

eating fish to these swampy areas. Cause: Overuse of antibiotics and failure to complete the full course of tablets has led to the selection of more virulent bacteria resistant to antibiotics. Antibiotics had a dramatic effect on world wide health when first introduced but their effectiveness has decreased over time. Each time an antibiotic is used, individual bacteria with a natural resistance are selected for, subsequently parenting the next generation of resistant bacteria. Superbugs such as Golden Staph have been the result. We are rapidly facing a time where very common infections will cause death again. To minimise these effects, antibiotics must only be taken to treat bacterial infections AND the full course of tablets MUST be completed.

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4. Often we recognise an infection by the symptoms it causes. The immune response is not so obvious, until we recover 1. identify defence barriers to prevent entry of pathogens in humans: – skin – mucous membranes – cilia – chemical barriers – other body secretions

We have 3 lines of defence against disease:  1st line is non specific, attempts to block entry  2nd line is non specific, Inflammation response and Phagocytosis and the Lymph System  3rd line is the specific immune response. The First Line of Defense Its main purpose is to prevent entry of pathogens into the body. This includes:  Skin – Provides a physical barrier  Mucous Membranes – These membranes line the respiratory and urino-genital openings. Sticky mucous traps the pathogens and flushes them out.  Cilia – Hair like structures lining air ages( nose, trachea and bronchial tubes  Chemical barriers – Stomach acid, Lysozyme in tears and saliva which breaks down cell walls of bacteria  Other body secretions – Chemicals in sweat glands also attack pathogens

2. identify antigens as molecules that trigger the immune response

An antigen is a molecule of protein embedded in the cell membrane of all cells. These proteins are unique to each and every organism. When a pathogen enters our body, our immune system recognises the antigen(antibody generator) as ‘not self’. This causes the immune system to begin production of antibodies to fight the invader.

3. explain why organ transplants should trigger an immune response

Any donated organ will be carrying antigens which the immune system will recognise as ‘not self’ and begin to attack. This causes the production of antibodies leading to organ rejection. 2nd Line of Defence = Inflammation Response, Non Specific 1. Inflammation Response - Large amounts of blood are sent to this area causing the red colour.Mast cells play a key role in the inflammatory process releasing Histamines which dilate blood vessels, causing many of the symptoms of allergies such as sneezing and runny noses. Antihistamines work by preventing the release of histamine from mast cells thereby blocking the allergic reaction.

4.4 identify defence adaptations, including: – inflammation response – phagocytosis – lymph system – cell death to seal off pathogen

2. Phagocytosis  Phagocyte detects chemicals released by a foreign intruder (e.g. bacteria)  Phagocyte moves up the concentration gradient towards the intruder  The phagocyte adheres to the foreign cell and engulfs it in a vacuole by an infolding of the cell membrane.  Lysosomes (organelles which are rich in digestive enzymes & found in the phagocytes cytoplasm) fuse with the vacuole & release their contents into it  During infection, hundreds of phagocytes are needed.  Pus is dead bacteria and phagocytes! 3. Lymph System Houses many lymphocytes responsible for producing

B and T cells. Lymph fluid ‘ively’ flows around the body. A lot of phagocytosis occurs here which is why the lymph nodes become swollen. The lymph nodes filter foreign particles, trapping them. 4. Cell Death Lymphocytes or macrophages completely surround pathogens forming a granuloma. The surrounding cells die which leads to death of the pathogen as it can no longer access a food source. This process forms pus. 5. Fever The body raises its temperature in an attempt to kill pathogens. If overdone, it can have very serious effects re enzymes. a. gather, process and present information from secondary sources to show how a named disease results from an imbalance of microflora in humans

Microflora are microscopic organisms such as bacteria, fungi and viruses. Our bodies are covered in them both internally and externally. Most of these are good/ helpful and their presence stops any bad microflora from taking hold. Diet, antibiotics and stress can upset the balance of these microflora giving the undesirable pathogens room to grow e.g Thrush. Thrush lives naturally all through the body but is kept in check by ‘good’ bacteria.

5. MacFarlane Burnet’s work in the middle of the twentieth century contributed to a better understanding of the immune response and the effectiveness of immunisation programs SYLLABUS STUDY NOTES This is the THIRD line of Defence. 1. identify the components of the NAME What is it What it does immune response: – antibodies Antibodies Proteins Antibodies bind onto – T cells produced by the antigens. The binding – B cells immune system may stop the biological when an antigen processes of the is detected. pathogen stopping the Each antibody is disease or may recruit specific. more macrophages to destroy the foreign substance B cell Lymphocyte Upon antigen formed in the recognition, divides and Bone marrow. multiplies rapidly to Ineffective against produce: pathogens hiding  Plasma cells which inside cells such produce

as viruses.

T cell

Antibodies. The role of antibodies B cells control the is to bind with Humoral antigens and response inactivate them so that other bodily processes can take over, destroy, and remove the foreign substances from the body.  Memory cells so that next time the response can be quicker. Lymphocyte T cells control the cell differentiates in mediated response ; the Thymus ultimate destruction of gland. pathogens. There are 4 types:  T helper  T memory  T Killer  T suppressor

2. describe and explain the immune response in the human body in of:  interaction between B and T lymphocytes  the mechanisms that allow interaction between B and T lymphocytes -the range of T lymphocyte types and the difference in their roles

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3. outline the way in which vaccinations prevent infection

BOTH B AND T CELLS ARE ATTACKING THE SAME ANTIGEN !!!! T Helper cells use cytokines to stimulate B cells into rapid multiplication. T Helper = Activate B and T cells to multiply rapidly and call in phagocytes. T Killer = kill pathogens using cytoxins. T Suppressor = Turn off the immune response. T Memory = Circulate in lymph ready for reinfection.

Inoculation is the introduction of an antigen into the body— usually through an injection—to stimulate the production of antibodies. It usually uses either dead pathogen cells(still with their antigen on the surface) or pathogens that have been weakened enough that they can’t make you sick. The immune system responds to the foreign antigen resulting in both T and B memory cells being created so that when the pathogen is met again in the real world, the body already has the knowledge to fight it, meaning you won’t get sick. 4. outline the reasons The cells in a donated organ will all be carrying an antigen for the suppression of which will stimulate the recipient’s immune response, the immune response in causing the donor organ to be rejected because it is “not organ transplant self”. Immuno-suppressant drugs must be taken for the rest patients of the patient’s life, leaving them susceptible to all other diseases. a. process, analyse and Smallpox is caused by the virus causing a rash of blisters on present information from the skin, which leave permanent scars. Smallpox was once a secondary sources to feared viral disease. The World Health Organization (WHO)

evaluate the effectiveness of vaccination programs in preventing the spread and occurrence of once common diseases, including smallpox, diphtheria and polio

mounted an aggressive worldwide campaign of immunisation and by 1977, the last naturally occurring case was detected in Somalia, but small stocks of the virus remain in laboratories. Polio is a serious infectious disease caused by a virus. Symptoms vary from mild, flu-like symptoms to lifethreatening paralysis. Between two and five per cent of people who develop paralytic polio will die. The Global Polio Eradication Initiative aims to eliminate all cases of polio around the world. The entire western Pacific region, including Australia, has been declared polio-free since 2000. Diphtheria is a serious contagious bacterial disease that causes severe inflammation of the nose, throat and windpipe (trachea) which can lead to suffocation, paralysis and heart failure if the toxins spread throughout the body. Around 10 per cent of people exposed to diphtheria die from the disease. It is extremely rare in most developed countries, including Australia, because of the widespread use of the diphtheria vaccine. However, there is a risk that the infection can be brought in by people who have travelled to developing nations.