immune system

• The innate immune system is the first line of defense against pathogens and is present from birth.
• The innate immune response is the first line of defense against pathogens.
• The adaptive immune system learns to recognize foreign substances, called antigens, and develops targeted responses against them.
• Antibodies are proteins produced by B cells that bind to specific antigens on pathogens or their products.
• T cells play an important role in cell-mediated immunity, which involves direct killing of infected cells.
• Your gut microbiome is a microscopic world within the world of your larger body. 

  The trillions of microorganisms that live there affect each other and their environment in various ways. 

  They also appear to influence many aspects of your overall health, both within the digestive system and outside of it.
• A diet high in fat and sugar and low in fibre can kill certain types of gut bacteria, making your microbiota less diverse
• High-level consumption of plant foods are associated with beneficial microbiome-related metabolomic profiles.
• The gut microbiota provides essential capacities for the fermentation of non-digestible substrates like dietary fibres and mucus swallowed which is not digested, including having or not having a cold.
• The microbiome is the community of microorganisms, such as fungi, bacteria and viruses, that exists in a particular environments. 

  In humans, the term is often used to describe the microorganisms that live in or on a particular part of the body.
• Some microbiome live on the surface of the skin and others in the body such as the gastrointestinal tract, for example. 

  These microorganisms are active and change in response to a host of environmental factors such as food eaten (gut), exercise (skin), medication (antibiotics) and other exposure.
• The oral cavity has the second largest and diverse microbiota after the gut harbouring over 700 species of bacteria.

  Microbes occupy surfaces of teeth, tongue, saliva, mucus and gums, each location has a unique composition.
• Some microbes are more suited to fluid substances or soft tissue and other harder such as the teeth enamel.
• The pulmonary (lung) microbial community consisting of a complex variety of microorganisms found in the lower respiratory tract particularly on the mucous layer and the epithelial surfaces.
• These friendly bacteria act as a protective barrier that stops the growth of bad bacteria and potential infections. 

  Q: What happens when there are more bad bacteria and fewer healthy bacteria? 

  A: When there's an imbalance in the vagina's pH levels, bad bacteria can grow.
• In human skin, the distribution and variety of glands and hair follicles vary among each geographic region. 

  The physical and chemical differences of skin regions create distinct composition of microbiota bacteria that live on your skin. 

  These help to break down the lipids to produce natural moisturizing factor for your skin, for example and effective homeostasis as well as immunity protection.
• Antibiotics, commonly prescribed to treat and prevent bacterial infections, are a cornerstone of modern medicine. 

  In the process of targeting the infection-causing bacteria in our bodies, antibiotics can also inadvertently wipe out the other (good) bacteria in our bodies.
• Pathogens are bad microorganisms and can cause illness and disease upon entering the body.

  All a pathogen needs to thrive and survive is a host eg. a human 

  Once the pathogen sets itself up in a host’s body, it manages to avoid the body’s immune responses and uses the body’s resources to replicate before exiting and spreading to a new host.
• Most common;

  • Bacteria
  • Virus
  • Fungi
  • Prions
  • Protists
  • Parasites
• Bacterium is a microscopic living organism which is a single cell.

  It is an unicellular microorganism which has a cell wall but no organelles such as mitochondria or a nucleus. Some but not all cause disease.

  Prokaryotes are single-celled organisms belonging to the domains Bacteria and Archaea.
• Fungi are mostly single celled or less so, very complex multicellular organisms which do have cell organelles.

  Fungi are eukaryotic cell  (has a nucleus) organisms that include microorganisms such as yeasts.

  Yeasts are microscopic fungi consisting of solitary cells that reproduce by budding.
• Prion diseases are a group of pathogens which effect the nervous system, and fatal disorders that affect some animal species and passed to humans.

  Creutzfeldt–Jakob disease (CJD) more commonly known as mad cow disease and is thought to pass to humans from eating meat from infected cattle.
• Protist are eukaryotic organisms

  Malaria is spread by mosquitos which carry Plasmodium protists. They pass the protist to humans they suck blood from. The mosquito does not become ill themselves, they are a transmitter, which is a vector.
• A virus is a microscopic infectious agent that replicates only inside the living cells of an organism. 

  Viruses infect all life forms, from animals and plants and are airborne

  One method of virus spread is the so-called droplet infection but droplets land on surfaces such as hands and can pass by contact infection and smear infection. A virus can be spread through blood, ingested too
• A parasite is an organism that lives on or in a host organism and gets its food from or at the expense of its host.

  They live in other host organisms and depend on them for survival. 

  Parasites that can affect humans include ticks, lice, and worms. Nematodes (roundworms), cestodes (tapeworms), and trematodes (flatworms)
• Lyme disease is a bacterial infection that can be spread to humans by infected ticks.

  Justin Bieber, Kelly Osbourne and Ben Stiller all have this disease
• Toxoplasmosis is a common infection that you can catch from the poo of infected cats, or infected meat. It's usually harmless but can cause serious problems in some people.

  In pregnancy, whilst infection in early pregnancy poses a small risk of foetal transmission (less than 6%), rates of transmission range between 60% and 81% in the third trimester