Module 2: Lecture 4

Question 1

what does immunity mean?

Answer 1

protecting you
- the body’s ability to protect itself (mainly from pathogens and anything that is abnormal)

Question 2

• how does immunity protect you?

Answer 2

by resisting or eliminating potentially harmful foreign invaders (eg. bacteria and viruses) or abnormal cells (eg. cancel cells) ie. foreign to the “normal self”

Question 3

what is the immune systems activities?

Answer 3

• 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

Question 4

• what is immune surveillance?

Answer 4

identifies and destroys abnormal or mutant cells that have originated in the body

Question 5

what is an allergen?

Answer 5

an antigen that causes an allergy

Question 6

what are the different types of pathogens that we are facing?

Answer 6

• bacteria
• viruses
• fungi
• protozoan parasites
• helminth parasites
• notion of virulence

Question 7

what is virulent?

Answer 7

a pathogen that can cause disease
- the inherent ability of a pathogen to cause disease

Question 8

what is avirulent or not virulent?

Answer 8

a pathogen that does not cause disease

Question 9

is bacteria eukaryotes or prokaryotes? what does this mean

Answer 9

prokaryotes
- they have no nucleus
- they have DNA, RNA
- single-celled microorganisms

Question 10

what does bacteria primarily cause?

Answer 10

tissue damage and cause disease by releasing enzymes or toxins
ex. Chlamydia, Streptococcus, E. coli, Salmonella

Question 11

what is the smallest pathogen?

Answer 11

viruses

Question 12

are viruses cells?

Answer 12

no

Question 13

what does a virus consist of?

Answer 13

either DNA or(NOT and) RNA enclosed by a protein coat

Question 14

what is the ONLY way a virus can carry out metabolism or reproduce?

Answer 14

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)

Question 15

examples of viruses?

Answer 15

SARS-CoV-2, HIV, HCV, Influenza, Ebola, Polio

Question 16

example of fungi?

Answer 16

• aspergillus
• candida

Question 17

are fungi eukaryotes or prokaryotes?

Answer 17

eukaryotes

Question 18

what are the two types of parasites of pathogens?

Answer 18

• protozoan parasites (eg. plasmodium causes malaria)
• helminth parasites (worms)

Question 19

what are the three types of external defenses we have?

Answer 19

1. mechanical (barriers)
2. chemical
3. microbiological

Question 20

what mechanical barriers do we have?

Answer 20

our skin, but all the epithelial cells that lines our skin, gut, lungs, all of our organs

Question 21

what mechanical barriers does the eyes/nose/oral cavity have?

Answer 21

tears and nasal cilia

Question 22

what are examples of the chemical barriers in the stomach?

Answer 22

low pH - it can destroy lots of bacteria

Question 23

what does antimicrobial peptides do?

Answer 23

slow down or stop the growth of certain types of pathogens (specifically, bacteria)

Question 24

what chemical barrier is there for the skin, gut, lungs and eyes/nose/oral cavity?

Answer 24

antimicrobial peptides

Question 25

what is the normal microbiota in our gut so important for?

Answer 25

to give us that immune protection from specifically things that we eat

Question 26

what are lymphoid tissues?

Answer 26

tissues that produce, store or process lymphocytes

Question 27

where does a pathogen gain entry?

Answer 27

the site of infection

Question 28

what does B lymphocytes make?

Answer 28

antibodies

Question 29

what does T lymphocytes do?

Answer 29

kill infected cells or cancer cells or command (the generals)

Question 30

what is your lymphatic system?

Answer 30

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

Question 31

what are the lymphoid tissues?

Answer 31

- bone marrow - thymus - lymph nodes - spleen - tonsils - adenoids - appendix - Peyer's patches or gut-associated lymphoid tissue (GALT)

Question 32

where is all our lymphoid cells and immune cells made?

Answer 32

in bone marrow

Question 33

where are T lymphocytes made?

Answer 33

start in bone marrow, travel to the thymus and develop into a T lymphocyte there - T for Thymus

Question 34

what are our two central lymphoid organs?

Answer 34

- 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

Question 35

why are lymphoid tissues strategically located?

Answer 35

to intercept invading microorganisms before they have a chance to spread very far - more in places that are more commonly infected

Question 36

what is the function of the spleen?

Answer 36

* 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

Question 37

(adaptive immunity) how long after infection, if never been infected by this pathogen before, will it take for your lymphocytes to get activated?

Answer 37

5 to 7 days - extremely slow

Question 38

how long after infection will our innate cells react?

Answer 38

within minutes to hours - extremely quickly

Question 39

what do our innate cells do?

Answer 39

- slow down the pathogen

Question 40

what would happen to us if we did not have our innate responses?

Answer 40

we would die because our adaptive responses are not fast enough

Question 41

what are the two types of immune responses?

Answer 41

innate and adaptive

Question 42

are innate responses selective or nonselective in defense against foreign material?

Answer 42

nonselectively defend

Question 43

what is our first line of defense, that is "non-specific", and rapid but with a limited response?

Answer 43

innate responses

Question 44

true or false: innate cells have receptors that see certain components of the pathogen

Answer 44

true - they see a specific part of the cell wall of bacteria

Question 45

what are the defenses of innate responses?

Answer 45

- inflammation - interferons (anti-viral) - natural killer cells (NK) - macrophages - complement system - dendritic cells

Question 46

which immune response selectively targets particular invaders?

Answer 46

adaptive responses

Question 47

what cell is responsible for humoral responses that are highly selective and involves production of antibodies?

Answer 47

B cells

Question 48

do T cells make antibodies?

Answer 48

no - they do a cell to cell action

Question 49

what are the two types of cell to cell action that T cells do?

Answer 49

1. T cell that kills an infected cell or kill a cancer cell - goes to directly kill the cell OR 2. the generals: the ones that go command the other cells

Question 50

what is antibody-mediated immunity (humoral)?

Answer 50

- involves productive of antibodies by plasma cells (B-lymphocyte derivatives)

Question 51

what is cell-mediated immunity?

Answer 51

- involves production of activated T lymphocytes - directly attack unwanted cells