Immune System Flashcards
what is the function of the immune system?
protects the body against invading pathogens including bacteria, protists, viruses, and fungi
the immune system includes what 3 things?
- the lymphatic system
- red bone marrow
- leukocytes (white blood cells)
describe how pathogens are filtered out of the body
tissue fluid enters the lymph capillaries > tissue fluid + lymph capillaries combine to form lymph vessels > skeletal muscle contractions move the lymph through the lymphatic system to the lymphatic ducts > lymphatic ducts dump back into the venous blood supply into the lymph nodes > lymph nodes filter the lymph of pathogens
where are lymph nodes located?
neck, armpits, groin
where do we have lymphatic tissue?
tonsils, adenoids, thymus, spleen, and Peyer’s patches
what is the thymus’ role in the immune system?
serves as a maturation chamber for the immature T cells that are formed in the bone marrow
what is the spleen’s role in the immune system?
cleans the blood of dead cells and pathogens
Peyer’s patches
located in the small intestine, protect the digestive system from pathogens
what are the body’s 5 general immune defenses?
- skin
- ciliated mucous membranes: cilia sweep pathogens out of respiratory tract
- glandular secretions: secretions from exocrine glands destroy bacteria
- gastric secretions: gastric acid destroys pathogens
- normal bacterial populations: compete with pathogens in the gut and vagina
phagocytes
pair up w inflammation responses to mobilize white blood cells and chemical reactions to stop infection
plasma proteins
act as the complement system to repel bacteria and pathogens
what are the 3 types of white blood cells that form the foundation of the immune system?
- macrophages: phagocytes that alert T cells to the presence of foreign substances
- T lymphocytes: directly attack cells infected by viruses and bacteria
- B lymphocytes: target specific bacteria for destruction
what 3 cells (not including the 3 main white blood cells) contribute to the body’s defense?
- memory cells
- suppressor T cells
- helper T cells
what are the 2 types of immune responses and when is each used?
- antibody mediated: in response to an antigen
- cell mediated: in response to an already infected cell
what happens when an invader that has previously attacked the body returns?
it is immediately recognized and a secondary immune response occurs
where are leukocytes produced?
red bone marrow
leukocytes can be classified as what 5 things?
monocytes, granulocytes, T lymphocytes, B lymphocytes, natural killer cells
Where are macrophages found?
- what is important to know about them?
found in lymphatic tissue, are the largest phagocytes that engulf and destroy pathogens
dendritic cells
present antigens (foreign particles) to T cells
neutrophils
short living phagocytes that respond quickly to invaders
basophils
alert the body of invasion
eosinophils
phagocytes that defend against multicellular invaders
what are the 4 types of T lymphocytes?
- what are T lymphocytes AKA?
helper T cells, killer T cells, suppressor T cells, memory T cells
- T cells
helper T cells
help the body fight infections by producing antibodies and other chemicals
killer T cells
destroy cells that are infected with a virus or pathogen and tumor cells
suppressor T cells
suppress other T cells when the battle is over
memory T cells
remain in the blood on alert incase the invader attacks again
B lymphocytes
- AKA?
produce antibodies
- B cells
antigens
substances that stimulate the immune system
antibodies
are produced for each antigen that enters the body
describe what happens when a pathogen or foreign substance enters the body
the pathogen is engulfed by a macrophage > macrophage presents fragments of the antigen on its surface > helper T cells + macrophage > killer B cells and T cells are activated > killer T cells destroy cells presenting the same antigens > B cells differentiate into plasma cells and memory cells
plasma cells
produce antibodies specific to that pathogen or foreign substance
innate immune system
- can it be acquired naturally/ artificially?
protects an individual from pathogens so that when an individual encounters infection or has an immunization, the individual develops an adaptive immunity that reacts to pathogens
- both
naturally acquired active immunity
- artificial acquired immunity
natural because the individual is exposed and acquires immunity without immunization
- artificial because the individual acquires immunity artificially (by a vaccine)
naturally acquired passive immunity
- artificially acquired passive immunity
natural because the antibodies are acquired during pregnancy as they move from the mothers bloodstream to the fetus. can also be transferred from a mothers breastmilk
- immunization that is given in outbreaks or emergency situations
