Overview

• Health isn't just about not being ill, it's the complete social, physical, and mental well-being of a person.
• A disease is any change in the normal function of a part of the body.
• Communicable diseases can be spread from person to person, while non-communicable diseases are not.
• Communicable diseases are normally caused by pathogens, which are microorganisms that can cause disease.
• Cholera is caused by bacteria and is mainly spread through water.
• Tuberculosis is spread by the bacteria and is mainly airborne.
• Chlorella vulgaris is a fungal disease and is spread through the air.
• Malaria is caused by a protist and is mainly spread by vectors.
• Helicobacter is spread by bacteria and is mainly spread through touch.
• HIV is a virus which is spread through bodily fluids.
• Chlamydia is spread by bacteria which is mainly spread through sexual contact.
• Viruses are a type of pathogen that can cause disease and are made up of genetic material surrounded by a taxid which is a special protein coat.
• Viruses don't have any of the structures that cells have, they don't have ribosomes and they can't reproduce themselves, they need to use living cells to replicate.
• There are two pathways to replicate viruses, the lytic pathway and the lysogenic pathway.
• In the lytic pathway, the virus inserts its genetic material into the cell and uses all of the cell parts to create new viruses, causing the cell to explode and releasing all of the viruses.
• In the lysogenic pathway, the virus still inserts its genetic material into the cell but it becomes a part of the cell's dna, replicating as the cell naturally divides until a trigger sends the virus into the lytic cycle.
• The human body has physical barriers such as the skin, mucus, and cilia, and chemical barriers such as stomach acid and lysozyme to stop pathogens from entering.
• The immune system, made up of white blood cells, is responsible for destroying pathogens.
• Phagocytes are white blood cells that engulf pathogens, while lymphocytes produce antibodies to rip apart the pathogen.
• Stimulating an immune response means your body begins creating lymphocytes that can create antibodies for the pathogen, so if you ever do get infected, your body already has the things it needs to fight the pathogen off.
• Monoclonal antibodies are used in pregnancy tests and can also be used to find tumors.
• Before a new drug can be used to treat an illness, it needs to go through a series of trials, starting with pre-clinical trials, where the new drug is tested on human tissue and live animals.
• In the UK, the law states that a new drug must be tested on two different species of live animals before it can move on to the next stage of clinical trials.
• Clinical trials involve testing the new drug on a group of healthy humans and a larger group of ill humans.
• Non-communicable diseases are diseases that cannot spread from person to person, mainly caused by lifestyle or genetics.
• Obesity is a lifestyle choice that can be caused by lack of exercise or a poor diet and has been clearly linked with lots of different health problems.
• Cardiovascular disease, or CVD, is a broad name for any problems with the heart or the blood vessels, and can be caused by fatty build up around arteries.
• Plants also have defenses they use to stop them from getting ill, such as a waxy cuticle over their leaves to protect them against any pathogens.
• Plant cells have cell walls which provide some extra protection for the cells.