Immune System - Lecture 1 Part B

Question 1

Where are all blood cells produced?

Answer 1

The bone marrow

Question 2

Which stem cells do all blood cells come from?

Answer 2

Hematopoietic stem cells

Question 3

What causes a Hematopoietic stem cell to differentiate into a specific blood cell?

Answer 3

Signals the the cell receives from the microenvironment

Question 4

What can Hematopoietic stem cells differentiate into?

Answer 4

Myeloid Progenitor or a Lymphoid Progenitor

Question 5

What cells do Myeloid Progenitors give rise to?

Answer 5

All the blood cells except lymphocytes
•RBCs
•Basophils
•Neutrophils
•Eosinophils
•Monocytes
•Macrophages

Question 6

What do Lymphoid Progenitor give rise to?

Answer 6

• Natural killer cells (NK cells)
• T lymphocytes
• B lymphocytes

Question 7

What do Granulocytes have in their cytoplasm?

Answer 7

Granules

Question 8

Which cells are Granulocytes?

Answer 8

• Neutrophils
• Eosinophils
• Basophils
• MAST cells

Question 9

What is another name for Neutrophils?

Answer 9

Polymorphonuclear leukocytes

Question 10

Why are Neutrophils also called Polymorphonuclear leukocytes?

Answer 10

Because their nucleus is multileveled

Question 11

What are the most abundant Granulocytes?

Answer 11

Neutrophils

Question 12

Which Granulocytes are the first to arrive at the site of an infection?

Answer 12

Neutrophils

Question 13

How do Neutrophils get to the site of an infection?

Answer 13

The migrate from the blood to the infected sites

Question 14

What do Neutrophils do once they arrive at the site of an infection?

Answer 14

They start Phagocytosis of the pathogen or antigen

Question 15

When do numbers of Neutrophils especially increase?

Answer 15

During a bacterial or fungal infection and acute inflammation

Question 16

How long do Neutrophils live for?

Answer 16

One or two days

Question 17

When do Eosinophil numbers increase?

Answer 17

During parasitic or worm infections. They also play a role in allergic reactions

Question 18

How do Eosinophils fight worms?

Answer 18

They cluster around them and release granules through degranulation that kill the pathogen

Question 19

What receptors are Eosinophils rich in?

Answer 19

IgE receptors

Question 20

What is IgE?

Answer 20

The antibody that is increased during parasitic infection

Question 21

When does Degranulation occur in Eosinophils?

Answer 21

When IgE from a parasite binds to it receptors

Question 22

Where are Eosinophils mainly found?

Answer 22

The GI tract, the lungs, and urinary and genital mucosa and in the skin

Question 23

What do Eosinophils release other than Granules?

Answer 23

Cytokines and Chemokine

Question 24

What do Cytokines and Chemokines released by eosinophils do?

Answer 24

During Inflammatory response recruit other cells to the site of an infection

Question 25

Why does the level of Eosinophils in the blood drastically increase?

Answer 25

To respond to infection

Question 26

What do Basophils have in their cytoplasm?

Answer 26

Granules

Question 27

Which Granulocytes are rare in blood?

Answer 27

Basophils

Question 28

Which Granulocytes are very Potent?

Answer 28

Basophils

Question 29

What is the mean of killing of Basophils?

Answer 29

Degranulation but they do not phagocytize after killing

Question 30

When are Basophils used?

Answer 30

During parasitic and allergic infections as well as reactions

Question 31

What do Basophils also release aside from Granules?

Answer 31

Histamines

Question 32

Which Granulocyte releases histamines?

Answer 32

Basophils

Question 33

What do Histamines do?

Answer 33

They increase vascular permeability and blood flow to the area facilitating the migration of other immune cells

Question 34

Which Granulocytes have heparin in their granules?

Answer 34

Basophils

Question 35

Where are Mast cells usually found?

Answer 35

In our skin and mucosal tissues

Question 36

When are Mast cells important?

Answer 36

During parasitic infections and allergic reactions

Question 37

What do the Granules of Mast cells contain?

Answer 37

Histamine

Question 38

What it responsible for the common symptoms during an allergic reaction?

Answer 38

Histamine

Question 39

What cells produce lipid mediators?

Answer 39

Mast cells

Question 40

What are some lipid mediators?

Answer 40

Prostaglandins and other cytokines

Question 41

What do Lipid Mediators do?

Answer 41

Help during inflammation activating other cells to fight against a pathogen

Question 42

What are the three antigen presenting cells?

Answer 42

Monocytes, Macrophages and dendritic cells

Question 43

What are Antigen presenting cells?

Answer 43

Cells that ingest and digest the antigen and present it to lymphocytes initiating an immune response

Question 44

What is a monocyte called once it migrates from the blood to the tissues?

Answer 44

A macrophage

Question 45

What is the lifespan of Macrophages?

Answer 45

A long time

Question 46

What do Macrophages do besides Phagocytosis?

Answer 46

Produce a lot of cytokines that help recruit other cells and regulate the immune response

Question 47

Which cell helps with tissue repair post-infection and post-inflammation?

Answer 47

Macrophages

Question 48

How do Macrophages help post-infection and post-inflammation?

Answer 48

They phagocytize dead cells and garbage that remain post infection and stimulate the production of collagen

Question 49

How do dendritic cells facilitate trapping a pathogen?

Answer 49

By their long projections of the cytoplasm that help them to phagocytize the pathogen

Question 50

What do Dendritic cells do after Phagocytizing a pathogen?

Answer 50

They migrate to the secondary lymph organs

Question 51

How do Dendritic cells trap pathogens?

Answer 51

Through their projections and Phagocytosis

Question 52

What do Natural Killer cells do?

Answer 52

Fight intracellular pathogens and find tumor cells and prevent their growth

Question 53

Why are NK cells considered to be a self-made immune response?

Answer 53

Because they don't have receptors for specific antigens and don't generate memory

Question 54

How do NK cells recognize their targets?

Answer 54

Through MHC1 a protein shared among several cells

Question 55

How do NK cells kill?

Answer 55

Through apoptosis or programmed cell death

Question 56

How do NK cells work?

Answer 56

They recognize abnormal MHC1 in cells that are infected or tumours and induce their death. They also have cytotoxic granules

Question 57

What chemical do NK cells produce and what does it do?

Answer 57

Interferon Gamma and it activates macrophages and enhances their phagocytic activity

Question 58

What does Interferon Gamma do?

Answer 58

Activates macrophages and enhances their phagocytic activity

Question 59

What do T lymphocytes become once they are activated?

Answer 59

Helper T-cells or Cytotoxic cells

Question 60

How do T-Cytotoxic cells fight against intracellular infection?

Answer 60

They induce apoptosis of infected cells and generate memory

Question 61

Why are T and B cells known as Adaptive immune responses?

Answer 61

Because they create memory

Question 62

What does it mean for T cells to only be able to recognize processed antigens?

Answer 62

They can only be activated if the antigen that is presented to them is presented by an antigen presenting cells like macrophages or dendritic cells that also have MHC molecules

Question 63

Which antigens do T cytotoxic cells recognize?

Answer 63

Those bound to MHC1 complexes

Question 64

Which antigens do T helper cells recognize?

Answer 64

Those bound to MHC2 molecules

Question 65

What type of antigens do B cells recognize?

Answer 65

Unprocessed antigens (those that have not been processed by other cells like macrophages)

Question 66

What is interesting about B-lymphocytes?

Answer 66

They can also be antigen presenting cells and present to T cells, especially T helper cells to activate them to produce antibodies

Question 67

What are the Mediators of the Humoral immune response?

Answer 67

B lymphocytes