Unit 5: The Immune System Flashcards
What is the immune system based on?
recognition with the help of cell surface proteins
Cell Surface Proteins
recognize foreign bodies
Pathogens
disease causing agent
What are examples of pathogens? (2)
- virus
- bacteria
Disease
something that disrupts the bay and its function
How many ways can pathogens be transmitted?
6
What are the ways pathogens can be transmitted? (6)
- contact
- cuts
- droplets/aerosols
- food/water
- sex
- insects
How can pathogens be transmitted via contact? (2)
- sick person touches healthy person and pathogen enters through opening
- not washing hand makes this easier
How can pathogens be transmitted via cuts? (2)
- pathogens enter the body and pass directly into the blood stream
- allowing the cut to bleed allows toxins to be flushed out
How can pathogens be transmitted via droplets? (2)
- someone sneezes on you and respiratory pathogens are breathed in
- aerosols and droplets hold pathogens that commonly cause respiratory disease
How can pathogens be transmitted via food/water? (2)
- pathogen enters the body through the gastrointestinal tract
- bacteria manifests itself in meat following death after some time
How can pathogens be transmitted via sex? (2)
- pathogens enter the body through the mucus membrane of the genitals
- the opening and mucus membrane allow for easy entry
How can pathogens be transmitted via insects?
you get bitten by a bug, the bug leave some part of its anatomy behind, pathogen in bug gets passed
What the ways the body can respond to a pathogen? (2)
- specifically
- non-specifically
What is the first part of a non-specific immune response?
detection and response
What are immune cells called? (2)
- leukocytes (white blood cells)
- there are several kinds
Leukocytes
detect cells that don’t have the same recognition markers which warrants a response
What is an example of an immune response? (2)
- allergic reaction
- rejection of organ in organ transplant
What is an external nonspecific defense?
skin and mucus membranes
How does skin protect the body? (2)
- skin is a physical barrier
- chemical secretions like sweat (acidic)
How do mucus membranes protect the body? (3)
- mucus membranes secrete liquid to flush away and trap pathogens
- has lysozyme
Lysozyme
an antimicrobial protein
What is an internal non-specific defense?
phagocytes and inflammation
How are phagocytes and inflammation internal non-specific defenses?
immune cells that are non-specific cells engulf any substances not produced by the body
What are the most common phagocytes? (2)
- neutrophils
- macrophages
What do phagocytes do?
engulf pathogens and digest them
Macrophages (2)
- absorb and break down pathogens
- large cell
What happens after tissue damage?
clotting
What are the steps of clotting? (4)
- clotting factors are release from damaged cells
- prothrombin becomes thrombin
- thrombin catalyzes reaction of fibrogen to fibrin
- fibrin mesh forms over found
Thrombin
catalyzes the reaction of fibrogen to fibrin
Fibrin
forms a mesh over a wound that traps erythrocytes and dries them out
Allergen
causes an autoimmune response
Allergy
an autoimmune response to an allergen
Autoimmune
immune system attacks itself
What are allergens produced by?
basophils and mast cells
What do allergens release?
histamines
Histamines (2)
- neurotransmitters which trigger an inflammatory response
- signals uncomfortable symptoms
What are some symptoms brought about by histamines? (3)
- vasodilation
- wakefulness
- anaphylaxis
What does a pathogen that causes a specific response have?
antigens
Antigens
marker proteins on the surface of cells
Lymphocyte
- cells that generate specific responses
- all lymphocytes are leukocytes, but not all leukocytes are lymphocytes
What are some lymphocytes? (4)
- B cells
- Helper T Cells
- Cytotoxic T Cells
- Natural Killer Cells
B Cells (4)
- produce antibodies
- located in bone marrow
- generalized stem cells
- some remain in body after infection as memory B cells
Antibodies
proteins that counteract a pathogen’s effect
Helper T Cells (2)
- help recruit other immune cells (B cells or macrophages
- usually the result of bacterial infection
Cytotoxic T Cells (2)
- destroy infected cells of the body
- usually the result of viral infection or tumors
Natural Killer Cells
act similar to Cytotoxic T Cells
MHC
the structure that represents antigens to immune cells
What are the 2 types of MHCs? (2)
- MCH 1
- MCH 2
MHC 1
found all cells of the body, present when cells are infected by a virus or cancer
What does MHC 1 present to?
cytotoxic T cells for destruction
MHC 2
- only on specific immune cells that digest pathogens (macrophages)
What does MHC 2 present to?
helper T cells and indirectly to B cells
What are the steps in antibody formation? (7)
- macrophage digests pathogen leaving the antigen
- MHC presents antigen to other cells
- Helper T cells bind to antigen and become activated, secreting chemical signals
- B and cytotoxic T cells are activated and recruited by helper T cell signals
- Plasma B cells make antibodies that are specific to antigen
- Antibodies disrupt function of pathogens
- Memory B cells go into circulation for later exposure
What are antibodies helpful for?
widespread infections
When does immunity arise?
when memory B cells are present in the body
What are the two types of immunity? (2)
- active immunity
- passive immunity
Active Immunity
body create its own antibodies following infection
What are the subcategories under active immunity? (2)
- natural active immunity
- artificial active immunity
Natural Active Immunity
resulting from exposure and subsequent infection
Artificial Active Immunity
arises as a result of vaccination
Passive Immunity
body receives antibodies, but does not make them on its own
What are the two subcategories under passive immunity? (2)
- natural
- artificial
Natural Passive Immunity
from mother to fetus through placenta or milk
Artificial Passive Immunity
a booster shot for rabies or tetanus
Clonal Selection
when they encounter an antigen, B cells will produce copies of themselves in order to produce large numbers of identical copies of antibodies
Antibiotics (2)
- work against bacterial infections
- disrupt some part of the bacteria’s metabolism
What is an example of an antibiotic? (2)
- penicillin works against a bacteria with peptidoglycan in its cell walls
- penicillin prevents the cell wall from being built which kills the bacteria
What happens if you take a large dose of antibiotics?
it takes some time to build the good bacteria community in your body
What can antibiotics not be used on?
viruses because it would affect the cell’s metabolism
Vaccine (2)
- a part of or an inactive form of a pathogen
- receiving vaccination activates a specific immune response to the pathogen, but without it reproducing
What happens as a result of vaccines?
after the first exposure, memory B cells produce more rapid response if there is exposure to the same pathogen again
What are the benefits of vaccination? (3)
- disease, death, and disability prevention
- allows for economic productivity
- disease can be wiped out
What are the risks of vaccination? (3)
- made for wrong strain or there is not enough
- the vaccine may overwhelm the immune system and leave it compromised
- possible side effects
Monoclonal Antibodies
allows for the production of large amounts of antibodies
What is the process of making monoclonal antibodies? (4)
- antigen is injected to produce an immune response
- the B cells, which respond and are specific to the antigen are extracted and put in culture
- the B cells are combined with tumor cells to produce a hydridoma
- antibodies are extracted from the tumor cells and used as medication
What are examples of the use o of monoclonal antibodies? (3)
- rabies booster shot
- pregnancy test
- COVID test
How do monoclonal antibodies apply to rabies booster shots? (2)
- rabies antibodies are produced because rabies usually kills a person before the system responds
- while monoclonal antibodies do not eradicate rabies, they clow the spread until the body responds enough
hybridoma
fusion of activated B cell and cancer cell
What is the cause of AIDS?
HIV
What does HIV infect?
cells that have CD4 molecules and class 2 MHC cells (helper T cells and macrophages)
What happens as a result of HIV affecting Helper T cells?
B cells have a diminished ability to produce antibodies, so any pathogen can kill an AIDS patient
Where does HIV reside?
in the lymph nodes, which is why it is never completely destroyed by the immune system
HIV
a retrovirus that synthesizes DNA from RNA with a high mutation rate
How long does it take HIV to destroy helper T cells?
10 years, then the immune system is compromised and the individual is considered to have AIDS
Why is it hard to fight off HIV?
it presents itself with your own antigens
How is HIV transmitted?
bodily fluids
What are ways HIV can be transmitted? (4)
- sexually
- blood transfusions
- sharing needles
- mother to infant