Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
31 Cards in this Set
- Front
- Back
|
Define Health |
Health can be defined as a state of normal functioning and disease and a state of impaired functioning. |
|
|
Define disease |
The state of impaired functioning |
|
|
How do genes assist in maintaining health? |
Genes control the process of protein synthesis (growth and maintenance, enzymes), regulate the cell cycle and control the growth and reproduction of cells. Genes contain the instructions for maintaining normal functioning of the body. |
|
|
How does mitosis assist in maintaining health? |
Mitosis is cell division, producing identical cells, part of the cell cycle. Every day, millions of cells die and are replaced by the process of mitosis. Mitosis is regulated by genes such as proto-oncogenes, tumour suppressor genes and the p53 gene. |
|
|
How does cell differentiation assist in maintaining health? |
Cell differentiation is the process undergone by cells after mitosis where particular genes are switched on and off. Thus the cell is specialised for a certain function. Unspecialised cells form tumours, so cell differentiation is highly important. |
|
|
How does cell specification assist in maintaining health? |
Cell specialisation is very important as unspecialized cells form tumours. Each cell has a special function and the cells in a multi-cellular organism work together efficiently to maintain health. |
|
|
What is the difference between an infectious and non infectious disease? |
An infectious disease is caused by a pathogen and can be transferred from one person to another. A non-infectious disease is caused by factors other than a pathogen (e.g. environment, genetics) and cannot be transferred from one person to another. |
|
|
Why does cleanliness in food, water and personal hygiene practices assist in the 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. |
|
|
How is drinking water treated? |
-Water passes through filtration plants which may remove pathogens e.g. protozoa. -Flocculants are added to bind microbes, dirt and other suspended matter together, making it easier to remove them by filtration. -Water is treated with chlorine or monochloramine to kill most organisms that may still be present. -Any remaining cryptosporidium spores are inactivated by these chemicals. |
|
|
What are Kosh's postulates? |
The organism believed to be the cause of the disease must always be present when the disease occurs. The organism must be isolated from the host and grown in pure culture. Organisms from the pure culture, when inoculated into healthy, suitable, susceptible hosts must produce the disease. The organism must be re-isolated, grown in pure culture and compared to the organism first injected. |
|
|
What is an antibiotic? |
Antibiotics are chemicals which inhibit or destroy microbes such as bacteria. There are many antibiotics but only some are useful for treating human disease. |
|
|
What is the difference between broad and narrow spectrum antibiotics? |
Broad-spectrum antibiotics act against a range of bacteria, including non-pathogenic forms. Narrow-spectrum antibiotics only act against one or two types of bacteria. |
|
|
Outline the history of Malaria. |
-Around 2700 B.C. , several characteristic symptoms of malaria were described in Chinese medical writings. The Greece recognised it by 4 B.C. as the cause of the decline of many cities. Hippocrates noted the principal symptoms. -Ancient Chinese healers traditionally used sweet wormwood to treat the symptoms of malaria. This ancient cure was forgotten until 1971 when a group of scientists led by Dr. Youyou extracted artemisinin, a potent anti-malarial compound. -In 1880, Charles Laveran, a French army doctor, observed the malarial parasite. -In 1897, Ronald Ross discovered the malarial parasite in the stomach of an Anopheles mosquito
|
|
|
What is the cause of Malaria? |
Malaria is caused by the parasitic protozoans of the genus Plasmodium. Four species of Plasmodium protozoa cause malaria in humans: P. falciparum, P. vivax, P. malariae and P. ovale. Plasmodium falciparum causes the most severe form of malaria (80% of infections, 90% of deaths). |
|
|
How is malaria transmitted? |
-When a mosquito bites an infected person, it picks up the parasite -These eggs form into Sporozoites -Sporozoites are transferred to the blood of the next human bitten by the mosquito. -Sporozoites infect the liver cells and by asexual reproduction produce -Merozoites, when released, infect red blood cells where they multiply and develop into gametocytes. -Gametocytes are released when red blood cells burst. |
|
|
What are the major symptoms of Malaria? |
Fever, Shivering, Chills, Profuse sweating, Anaemia, Headache, Vomiting, Abdominal pain, Coma and death in severe cases |
|
|
What is the hosts response to malaria? |
Cytotoxic T cells can attack Plasmodium during the liver stage as they destroy infected liver cells. -Helper T cells stimulate macrophages to remove infected red blood cells. -Cytokines are cellular factors that activate macrophages to attack blood stage parasites. Macrophages can kill Plasmodium -Antibodies produced by plasma cells neutralize parasites when they are exposed Parasites evade immune system while in the RBC. -The composition of the surface antigens of the parasite change so they may not be recognised by the host’s immune system. |
|
|
What is the treatment for malaria? |
Anti-malarial drugs are used to treat malaria. A combination of drugs is used to overcome the increasing resistance of Plasmodium to these drugs. These include chloroquinine, quinine and artemisinin. |
|
|
What is the preventative methods for malaria? |
-Use of anti-malarial drugs prophylactically -Avoidance of bites by mosquito in malaria-prevalent areas -Spraying of inside surfaces of walls and ceilings with insecticides -Long-sleeved clothing and pants -Use of insect repellent -Mosquito nets |
|
|
What are ways to control the spread of Malaria? |
-Prevention of mosquito breeding by draining swamps and stagnant water -Spraying breeding areas with oil and insecticide -Introducing fish that feed on mosquito larvae -Genetically modifying mosquitos so that they are no longer vectors for the Plasmodium -Research into a vaccine for malaria is currently being conducted |
|
|
What is an antigen? |
Antigens are molecules which trigger an immune response e.g. bacteria, viruses, foreign marker on cell membrane. |
|
|
Describe the inflammation response. |
Tissue around the wound becomes hot to inhibit activity of pathogens by denaturing the enzymes of the pathogen. Chemicals such as histamine are released, causing the tissue becomes swollen as capillaries swell to increase blood circulation to the area, allowing more white blood cells to be released to attack pathogens. |
|
|
Describe phagocytosis. |
Neutrophils, manufactured in the bone marrow and found in blood-lymph and body tissues, ingest bacteria and the enzymes break down the bacterium. Macrophages engulf foreign particles and poisons, common in the liver and lymph glands, and are more commonly involved in fighting off long infections. |
|
|
How does the lymph system defend against pathogens? |
Lymph nodes filter the lymph fluid and remove pathogens, dead cells and other debris. Lymph nodes contain phagocytes to destroy any foreign material. |
|
|
How does cell death defend against pathogens? |
If other responses cannot control the pathogen, a layer of dead cells (granuloma) is formed around infection site, followed by a layer of macrophages. Pathogens eventually die and are consumed by macrophages. |
|
|
How can an imbalance of microflaura results in disease? |
Thrush is a disease caused by excessive growth of the yeast-like fungus Candida albicans. The fungus occurs naturally in the mouth, respiratory tract, female genital tract and gastrointestinal tract. When the numbers of the fungus are not kept in check by bacteria, thrush occurs. This is due to an imbalance in microflora. |
|
|
What is an antibody? |
-A protein produced when the body detects certain antigens -Corresponds to a specific antigen -Join with antigens, causing them to clump together to form an antibody-antigen complex -Antigen-antibody complex is more easily recognised and destroyed by macrophages than antigens alone |
|
|
What is a B cell? |
-Lymphocyte produced in the bone marrow -Controls antibody mediated immunity -When a B cell recognises an antigen, it is cloned to produce a mass of identical cells. -The B cells work as antibody producers (plasma cells) or memory B cells which provide long-term immunity. |
|
|
What is a T cell? |
-Lymphocyte produced in bone marrow -Matures in the thymus gland -controls cell mediated immunity -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. DONT PRODUCE ANTIBODIES THOUGH |
|
|
How do vaccinations prevent infection? |
Vaccination is a method of providing artificially acquired immunity without the need for a person to have suffered the disease initially. |
|
|
What is epidemiology? |
Epidemiology is the study of the prevalence of disease in the community and involves the collection and careful statistical analysis of large quantities of datafrom a large population to assist in identifying the cause of diseases. |
