When physiological processes malfunction, the body tries to repair the damage. The process is similar in all living things and it is only when the process fails to contain the damage that disease can be recognized.
Humans have long recognized the symptoms of disease both in themselves and the animals and plants around them. Since the beginnings of recorded history, they have noted the signs that reveal that the body is malfunctioning. Increasing understanding of the causes of disease together with accompanying advances in technology have changed approached to treatment and management of disease. The search for measures to treat and manage diseases of humans and other organisms continues and this search is paralleled by continued refinements in technology.
Health is usually defined with respect to physical, mental and social wellbeingin which body functions are normal.
However, health can vary on a daily Search for better health notes and refer to more than the absence of disease. The standards for health vary with age and susceptibility to disease. They can be subjectivedepending on physical activity, sensitivity to pain, inner happiness and work ethic.
Disease is any condition "Search for better health notes" adversely affects the functioning of an organism. This definition is very broad, and can cover minor conditions e.
Genes control the process of protein synthesis growth and maintenance, enzymesregulate the cell cycle and control the growth and reproduction of cells. Genes contain the instructions for maintaining normal functioning of the body. Mitosis is cell division, producing identical cells, part of the cell cycle. Every day, millions of cells die Search for better health notes are replaced by the process of mitosis.
Mitosis is regulated by such as proto-oncogenes, tumour suppressor genes and the p53 gene. 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.
Cell specialisation is very important as unspecialized cells form tumours. Each cell Search for better health notes a special function and the cells in a multi-cellular organism work together efficiently to maintain health.
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. 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.
A pathogen is an infective agent that can cause disease. They are often host-specificthrough recently some have been known to cross species.
Antibiotics are chemicals which inhibit or destroy microbes such as bacteria. There are many antibiotics but only some are useful treating human disease. InAlexander Fleming discovered the first antibiotic, penicillinderived from the fungus Penicilliumwhich could destroy staphylococcus colonies. InHoward Florey and Ernst Chain showed that penicillin was effective in treating infectious disease and developed a method for its production in large quantities.
It was widely used in WWII for both soldiers and later civilians. 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. After "Search for better health notes" few weeks, the flask with straight tubing "Search for better health notes" microbe growth, in clumps of white floating on the surface.
The flask with the swan-necked tubing showed no microbial growth. This demonstrates that microbes from the air can enter through the straight tubing and Search for better health notes and grow in the meat broth, but the swan-necked tubing prevented microbes from entering the flask.
Microbes cannot spontaneously generate inside the flask. Malaria probably originated in Africa in prehistoric times, and accompanied human migration Search for better health notes the Mediterranean shores, India and South East Asia. The Greece recognised it by 4 B. Hippocrates noted the principal symptoms. In the Susrutaa Sanskrit medical treatise, symptoms of malarial fever were described and attributed to the bites of certain insects. Ancient Chinese healers traditionally used sweet wormwood to treat fevers and the symptoms of malaria.
This ancient cure was forgotten until when a group of scientists led by Dr. Youyou rediscovered sweet wormwood and extracted artemisinina potent anti-malarial compound. Quechua healers of South American tribes in the Amazon used the bark of the Cinchona shrub to treat fevers
Search for better health notes shivering. In the s, this was observed by Spanish priests in the region, who started using it to treat fevers associated with malaria.
Bythe bark was available in England. The active ingredient, quinine, was isolated in by Pierre Joseph Pelletier. Quinine is one of the most effective anti-malarial drugs today. InCharles Laveran, a French army doctor, observed the malarial parasite.
He was awarded the Nobel Prize for his work in InGolgi observed asexual reproduction in the protozoan Plasmodium and identified two species. InRonald Ross discovered the malarial parasite in the stomach of an Anopheles mosquito.
Search for better health notes parasite is the protozoa of the genus Plasmodium transmitted by the female Anopheles mosquito. InGiovanni Grassi named the Anopheles mosquito as the carrier of the malarial parasite. InHans Andersag discovered chloroquinine, a synthetic drug.
He named the compound resochin. Chloroquinine is an effective and safe
Search for better health notes, though it was not recognised as such by British and American scientists until It was first used in Italy inand idea of global eradication of malaria seemed possible.
Subsequently, widespread systematic control of the Anopheles mosquito has been used to interrupt its lifecycle, including the spraying of DDT, coating marshes with paraffin, using mosquito nets and draining stagnant water. However, mosquito populations develop resistance to DDT, limiting is effectiveness. In recent years, many charities have realised the potential of inexpensive mosquito nets in preventing the spread of malaria by preventing physical contact between the vector and host.
They also provide education for the people about the prevention of the spread of malaria. When travelling to malaria-infested regions, as well as using mosquito nets, it is also advised to use insecticide before entering a building, wear mosquito repellent cream, and wear appropriate clothing: This prevents the occurrence of mosquito bites.
A great variety of anti-malarial drugs, including chloroquinine, are available today. Malaria is thought to cause around 2.
Currently there is research into a vaccine against malaria. Phase 3 trials are being conducted in Africa. Malaria is caused by the parasitic protozoans the genus Plasmodium. Four species of Plasmodium protozoa cause malaria in humans: The vector for malaria is the female Anopheles mosquito. There are around species of Anopheles mosquito but only species transmit 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. Bacteria that are resistant to antibiotics survive and quickly reproduce, passing on the resistant gene so that entire populations are resistant to antibiotics. This means that bacterial population quickly "Search for better health notes" resistant to an antibiotic, reducing its effectiveness. Some superbugs are resistant to nearly all antibiotics available to us today. Antibiotics should be only prescribed when absolutely necessary, and then the full course should be taken.
They should also be limited in the food supply from agriculture. Antigens are molecules which trigger an immune response e.
Organ transplants trigger an immune response. The transplant tissue is not identified as self by the body. Antigens on the surfaces of cell membranes mark it foreign and it will trigger an immune response.
The body rejects the tissue by producing antibodies against it — immune-suppressor drugs must be taken to prevent this rejection, but this renders the patient susceptible to pathogens. Thrush candidiasis is a disease caused by excessive growth of the yeast-like fungus Candida albicans. The fungus occurs naturally in the mouth, respiratory tract, female "Search for better health notes" 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 microflorathe populations of naturally occurring microbes in the human body. Symptoms include itchiness, drying, redness and swelling. Diagnosis can involved taking a swab of the infected area and examining for cells under a microscope.
Antibiotics are often the cause, as they kill the natural bacteria that keep the fungus in check. Contraceptive pills, diabetes and pregnancy can also cause an imbalance in microflora. Vaccination is a method of providing artificially acquired immunity without the need for a person to have suffered the disease initially. An immune response occurs and the immune system attacks the transplanted tissue.
Cytotoxic T cells, macrophages and antibodies attack the tissue that has been distinguished as non-self by lymphocytes, leading to tissue rejection. Below Search for better health notes the syllabus dot Search for better health notes of Search for Better Health.
Click on the dot point to expand relvant information. These notes were written by. – The Search for Better Health: 1. is a healthy organism? • Discuss the difficulties in defining the terms 'health' and 'disease': – 'Health' is difficult to.
Biology Notes. Module 3 – The Search For Better Health. 1. What is a healthy organism? •. Discuss the difficulties of defining the terms 'health'.