Immunology part 1

Question 1

3 key properties of a NORMAL immune system

Answer 1

highly diverse group of antigen receptors
immune memory
immunologic tolerance

Question 2

antigen receptors allow

Answer 2

for recognition of plethora of pathogens

Question 3

immune memory allows for

Answer 3

rapid recall of immune responses

Question 4

immunologic tolerance prevents

Answer 4

immune damage to normal self tissue

Question 5

A pathogen is

Answer 5

any organism that has the potential to cause disease

Question 6

what are the three roles of the immune system

Answer 6

1. defend against invasion
2. distinguish between self and invader
3. defend against abnormal cells/molecule formation in the body (neutralize anything that does get in)

Question 7

immunity is

Answer 7

our bodies way of defending against pathogens and foreign substances that cause disease

Question 8

immune system is

Answer 8

the collection of cells, tissues, and molecules that mediate the resistance efforts.

Question 9

immune response

Answer 9

coordinated reactions of those cells and molecules against infectious microorganisms

Question 10

The most important function in our immune system is

Answer 10

defending against infection by preventing infection and/or eliminating established infections

Question 11

What is innate/natural immunity and what does it include

Answer 11

The 1st line of immune defense. includes skin and epithelial layers which physically separate the body from external environment.

Question 12

What is adaptive/acquired immunity and what does it include

Answer 12

2nd line of immune defense, found only in vertebrates, adaptive immunity/antigen specific immunity. (dependent on influences from the innate immune system

Question 13

What is the initial protection in the body that acts immediatly

Answer 13

innate immunity

Question 14

what is the slower specialized response in the body

Answer 14

adaptive immunity

Question 15

Describe innate immunity in terms of:
response time
diversity
microbe recognition
principle immune cells involved
memory

Answer 15

response time: immediate (minutes to hours)
diversity: limited number of antigens recognized and limited number of groups of microbes identified.
Microbe Recognition: general patterns on microbes, nonspecific
principle immune cells involved: granulocytes, monocytes/macrophages, natural killer cells and dendritic cells.
memory: no memory, responds the same way to repeat encounters with the same pathogen

Question 16

Describe innate immunity in terms of:
response time
diversity
microbe recognition
principle immune cells involved
memory

Answer 16

response time: Delayed (takes days to weeks)
diversity: large number of highly selective antigens recognized
microbe recognition: specific to individual microbes and antigens
principle immune cells involved: B lymphocytes, T lymphocytes, dendritic cells, natural killer cells.
memory: yes, responds more effectively after each encounter with the same pathogen.

Question 17

Where do the cells involved in immunity come from?

Answer 17

bone marrow and lymph tissue

Question 18

Epithelial barriers:
Where are they found (give examples)
what are the subcategories
what do the subcategories consist of

Answer 18

found in all portals of entry into the body such as skin, respiratory, GI and urogenital tracts
subcategories are mechanical/physical barriers, chemical barriers, and microbiological/cellular barriers.
Mechanical/physical barriers = flow of fluids (persperation, mucus, saliva, urine, tears
chemical = sebum, enzymes, lysozymes in nasal secretions, acidity in vaginal secretions, and lysozymes in tears, antimicrobial peptides.
microbiological/cellular = normal flora of skin, GI tract, respiratory tract, urogenital tract and eyes.

Question 19

what are the cells of the innate immune system and what do they stem from

Answer 19

all immune cells stem from stem cells and innate cells are divided into a subgroup called “myeloid progenitors”. These are mostly granulocytes (included neutrophils, eosinophils, basophils and mast cells) as well as monocytes (which stem into dendritic cells and macrophages)

Question 20

Monocytes
granulocyte or agranulocyte
what do they do
facts (6 of them total)

Answer 20

Agranulocytes
- circulate in the blood
-largest WBCs
- precursors of tissue macrophages (turn into macrophages when they leave blood and enter tissues)
- when they enter tissues, they become macrophages and are sometimes given special names depending on their location (ex. cilia are macrophages of the lungs)
- monocytes may also mature into dendritic cells.

Question 21

Macrophages

Answer 21

Agranulocytes
-monocyte-macrophages are the first phagocyte microbes encounter when entering the host
-essential for clearing bacteria that gets past epithelial barrier in multiple organs.
-perform phagocytosis to get rid of microbes
-produce cytokines that help initiate inflammation and recruitment of other cells to the tissue site.
-present antigens to T lymphocytes
-non-immune function is to act as garbage disposals.

Question 22

what is the first phagocyte that microbes encounter when entering a host

Answer 22

monocyte/macrophages.

Question 23

Dendritic cells

Answer 23

-reside in body’s tissues (skin, mucosal membranes)
-serve as cellular messengers that initiate adaptive responses
-present antigens to T lymphocytes

Question 24

Where did dendritic cells get their names

Answer 24

named due to thin projections on their surface

Question 25

How do dendritic cells accomplish initiating adaptive immune responses

Answer 25

by degrading pathogens from infected tissues and transport them to organs that specialize in synthesizing adaptive immune responses.

Question 26

Natural Killer Cells

Answer 26

-lymphocyte cell that functions in innate immunity
-circulates in blood until its needed into the tissues
-doesnt directly recognize pathogens via antigen receptors but instead has membrane receptors that recognize damaged cells
- release contents of their granules that cause LYSIS and/or apoptosis to destroy target cells
-help limit spread of infection via cytokine production

Question 27

Why are natural killer cells called natural

Answer 27

because they are active without having been exposed to a virus previously, they do not have to be activated

Question 28

what are 2 examples of cells that natural killer cells may recognize as damaged cells

Answer 28

virus-infected cells
tumor cells

Question 29

The granulocytes of innate immunity are

Answer 29

neutrophils, eosinophils and basophils

Question 30

What happens if accumulation of granulocytes continues unchecked, why

Answer 30

can lead to host tissue damage, not sure why, think on this later

Question 31

Neutrophils

Answer 31

-most abundant circulating granulocyte
-circulate in bloodstream but will die after a few days if not sent to site of bacteria infection
–kill bacteria via phagocytosis (contain cytoplasmic granules with toxic substances that kill/inhibit bacteria and sometimes fungi.
-activatea respiratory burst that produces reactive oxygen species (ROS) to attack pathogens
-produce neutrophil extracellular traps (NETs) which immobilize pathogens, facilitate phagocytosis and directly kill pathogens.

Question 32

What are the three ways that neutrophils kill bacteria

Answer 32

using cytoplasmic granules
activating respiratory burst
producing neutrophil extracellular traps

Question 33

eosinophils

Answer 33

-second most abundant circulating granulocyte
- recruited into tissue in response to large parasitic worm infections (Helminths)
-release granules containing toxic proteins, peroxidase, and other hydrolytic enzymes
=can also be associated with allergic responses
-can display surface membrane receptors for IgE antibodies.