Module 2: Lecture 4 Flashcards
what does immunity mean?
protecting you
- the body’s ability to protect itself (mainly from pathogens and anything that is abnormal)
- how does immunity protect you?
by resisting or eliminating potentially harmful foreign invaders (eg. bacteria and viruses) or abnormal cells (eg. cancel cells) ie. foreign to the “normal self”
what is the immune systems activities?
- defends against invading pathogens
- removes “worn-out” cells and tissue damaged by trauma
- identifies and destroys abnormal or mutant cells that have originated in the body –> immune surveillance
- mounts inappropriate immune responses that lead either to allergies or to autoimmune diseases
- what is immune surveillance?
identifies and destroys abnormal or mutant cells that have originated in the body
what is an allergen?
an antigen that causes an allergy
what are the different types of pathogens that we are facing?
- bacteria
- viruses
- fungi
- protozoan parasites
- helminth parasites
- notion of virulence
what is virulent?
a pathogen that can cause disease
- the inherent ability of a pathogen to cause disease
what is avirulent or not virulent?
a pathogen that does not cause disease
is bacteria eukaryotes or prokaryotes? what does this mean
prokaryotes
- they have no nucleus
- they have DNA, RNA
- single-celled microorganisms
what does bacteria primarily cause?
tissue damage and cause disease by releasing enzymes or toxins
ex. Chlamydia, Streptococcus, E. coli, Salmonella
what is the smallest pathogen?
viruses
are viruses cells?
no
what does a virus consist of?
either DNA or(NOT and) RNA enclosed by a protein coat
what is the ONLY way a virus can carry out metabolism or reproduce?
by invading a host cell (non-self sustaining entities)
- they cannot sustain their own cells, they cannot make more viruses without going into an actual cell
- viruses have to infect the cell, live inside it, make the cell make more virus for them (viruses don’t have organelles to make them themselves)
examples of viruses?
SARS-CoV-2, HIV, HCV, Influenza, Ebola, Polio
example of fungi?
- aspergillus
- candida
are fungi eukaryotes or prokaryotes?
eukaryotes
what are the two types of parasites of pathogens?
- protozoan parasites (eg. plasmodium causes malaria)
- helminth parasites (worms)
what are the three types of external defenses we have?
- mechanical (barriers)
- chemical
- microbiological
what mechanical barriers do we have?
our skin, but all the epithelial cells that lines our skin, gut, lungs, all of our organs
what mechanical barriers does the eyes/nose/oral cavity have?
tears and nasal cilia
what are examples of the chemical barriers in the stomach?
low pH - it can destroy lots of bacteria
what does antimicrobial peptides do?
slow down or stop the growth of certain types of pathogens (specifically, bacteria)
what chemical barrier is there for the skin, gut, lungs and eyes/nose/oral cavity?
antimicrobial peptides
what is the normal microbiota in our gut so important for?
to give us that immune protection from specifically things that we eat
what are lymphoid tissues?
tissues that produce, store or process lymphocytes
where does a pathogen gain entry?
the site of infection
what does B lymphocytes make?
antibodies
what does T lymphocytes do?
kill infected cells or cancer cells or command (the generals)
what is your lymphatic system?
a system that drains all your sites into nodes and your lymphocytes (your most powerful immune cells) go check in those nodes. they circulate throughout all your nodes. if there is an infection, they stay and make more
what are the lymphoid tissues?
- bone marrow
- thymus
- lymph nodes
- spleen
- tonsils
- adenoids
- appendix
- Peyer’s patches or gut-associated lymphoid tissue (GALT)
where is all our lymphoid cells and immune cells made?
in bone marrow
where are T lymphocytes made?
start in bone marrow, travel to the thymus and develop into a T lymphocyte there
- T for Thymus
what are our two central lymphoid organs?
- bone marrow
- thymus
- where our lymphocytes (all our immune cells) are made and developed
- not where they do their job because there is rarely infections here
why are lymphoid tissues strategically located?
to intercept invading microorganisms before they have a chance to spread very far
- more in places that are more commonly infected
what is the function of the spleen?
- removes the worn out RBCs by macrophages
WHAT IS BELOW WAS ALREADY MENTIONED
- exchanges lymphocytes with the blood (removes, stores, produces, and adds them)
- resident lymphocytes produce antibodies and activated T cells, which are released into the blood
(adaptive immunity) how long after infection, if never been infected by this pathogen before, will it take for your lymphocytes to get activated?
5 to 7 days
- extremely slow
how long after infection will our innate cells react?
within minutes to hours
- extremely quickly
what do our innate cells do?
- slow down the pathogen
what would happen to us if we did not have our innate responses?
we would die because our adaptive responses are not fast enough
what are the two types of immune responses?
innate and adaptive
are innate responses selective or nonselective in defense against foreign material?
nonselectively defend
what is our first line of defense, that is “non-specific”, and rapid but with a limited response?
innate responses
true or false: innate cells have receptors that see certain components of the pathogen
true
- they see a specific part of the cell wall of bacteria
what are the defenses of innate responses?
- inflammation
- interferons (anti-viral)
- natural killer cells (NK)
- macrophages
- complement system
- dendritic cells
which immune response selectively targets particular invaders?
adaptive responses
what cell is responsible for humoral responses that are highly selective and involves production of antibodies?
B cells
do T cells make antibodies?
no
- they do a cell to cell action
what are the two types of cell to cell action that T cells do?
- T cell that kills an infected cell or kill a cancer cell - goes to directly kill the cell
OR - the generals: the ones that go command the other cells
what is antibody-mediated immunity (humoral)?
- involves productive of antibodies by plasma cells (B-lymphocyte derivatives)
what is cell-mediated immunity?
- involves production of activated T lymphocytes
- directly attack unwanted cells
