The immune system Flashcards
(23 cards)
What is a disease?
A condition that stops the body or any parts from working properly. Disease can be caused by lifestyle.
What is an infectious disease?
An infectious disease is due to a microorganism and can be spread or transferred from one organism to another. A pathogen causes disease, A non-infectious disease cannot be spread from one person to another
What is bacteria?
Bacteria are microscopic, unicellular organisms, some can be treated with antibiotics. Some bacteria are pathogen and can be ‘good’
What is a virus?
A virus is 1/100 the size of bacteria, They are non-living structures and have no cells. They cannot produce outside another cell.
What are Fungi?
Fungi are unicellular or have filaments. They reproduce by means of spores, which grow in warm, moist environments of the human body.
What is a fungal infection?
They are contagious and are difficult to treat. E.g. tinea, thrush
How can microbes enter?
Skin, Gastrointestinal tract, respiratory tract, urogenital, mucous membranes
A portal of exit for the microbes?
The gastrointestinal and respitory tracts
How can infectious diseases be transmitted?
Person to person contact, sexually transmitted diseases, coughing, sneezing, food poisoning, insect bites.
What is Pseudoscience?
Beliefs or theories that claim to be backed up by science, but the science is incomplete or false. It is published in peer-reviewed scientific journals.
What is the first line of defence?
Physical and chemical barriers. E.g. skin, tears, cilia, stomach acid, urine flow. Microorganisms that live all over your body. Cilia lines the nose, throat, gut and have surface projections in the small intestine.
What is the second line of defence?
An infection occurring inside the body causes a non-specific response (Phagocytosis) followed by an inflammatory response (swelling).
What is the third line of defence?
Very specific, start a range of protective processes. White blood cells (T and B cells) mature in the thymus and bone marrow, and then travel to the lymphatic system (lymph nodes throughout the whole body)
What are B cells?
B cells find foreign particle, outside cells and send antibodies, to lock onto them and destroy them. (Send antibodies- protein on surface of cell)
What are T cells?
T cells are like soldiers, where they destroy the foreign particles that the B cells (intelligence system) finds infections within the cell.
What is an Antigen?
Foreign substance (part of a virus) that sits on the surface of the pathogens. Antigens are “recognised” by the cells of the immune system as “non-self.”
What are Antibodies?
Antibodies (produced by B cells) and proteins found in blood and attach onto antigen to kill invading pathogens. Specific antibodies can only combine with specific antigens.
What can bacteria do?
Bacteria may make toxins that can paralyze, destroy cells’ metabolic machinery, or precipitate a massive immune reaction that is toxic.
What are vaccinations?
They work by stimulating the body’s defence mechanisms to provide protection against infection in future. Vaccines are a harmless form of disease (antigen) create immunity without causing disease.
What is immunisation?
It is the process of both receiving a vaccine and becoming immune to the disease as a result. The immunity is only for that disease.
What are hormones?
Hormones are chemical substances; they act as messengers in the body. They are produced in endocrine glands that are connected by blood vessels.
Pathogen
A pathogen is a disease-causing microorganism, including viruses, bacteria, fungi, and parasites. They can be harmful to humans if they enter the body and overwhelm the immune system.
Microorganisms
A microorganism, also known as a microbe, is a tiny living thing that is too small to be seen by the naked eye. They are typically observed using a microscope. Examples of microorganisms include bacteria, viruses, fungi, and algae
