3 - Cells and Organs of The Immune System

Question 1

Where do all immune cells come from? (what cells?)

Answer 1

hematopoietic stem cells (HSC)

Question 2

Which organ do hematopoietic stem cells come from?

Answer 2

bone marrow

Question 3

What does the term “leukocytes” mean?

Answer 3

differentiated cells from HSC that contain a nucleus

Question 4

When do red blood cells (RBCs) lose their nucleus?

Answer 4

when they leave the bone marrow and develop

Question 5

What is the difference in cases when adults have nucleated RBCs in their blood as opposed to when infants do?

Answer 5

in adults = abnormal = indicates something is wrong | in infants = normal

Question 6

What are megakaryocytes?

Answer 6

platelets

Question 7

What are granulocytes?

Answer 7

immune cells with granules present

Question 8

What are the 3 granulocytes?

Answer 8

neutrophils, basophils, eosinophils

Question 9

What are neutrophils also called?

Answer 9

poly-morpho nuclei (PMN)

Question 10

What cells have multi-lobed nuclei and what does “multi-lobed nuclei” mean?

Answer 10

granulocytes | nucleus is not just one lobe, it has more than 1 (ex: bi-lobe)

Question 11

What is a high neutrophil count in the circulation indicate?

Answer 11

indicates bacterial infection

Question 12

What are the 2 major types of progenitor cells?

Answer 12

common myeloid progenitor (CMP) and common lymphoid progenitor (CLP)

Question 13

Which progenitor cell gives rise to dendritic cells?

Answer 13

both CMP and CLP`

Question 14

Out of all of the blood cells, which cells last for days to years? (long time)

Answer 14

lymphocytes

Question 15

Which white blood cells last for the shortest time?

Answer 15

neutrophils (6-48 hours)

Question 16

What is the function of neutrophils?

Answer 16

leave circulation &raquo_space;> go to infected tissue &raquo_space;> blow themselves up to cause direct harm to pathogen

Question 17

What do basophils indicate? What do they stain with?

Answer 17

allergic infection and inflammation | basic dye

Question 18

What do eosinophils indicate? What do they stain with?

Answer 18

commonly allergic reactions | also viral and parasitic infections | acidic dye = red granules

Question 19

What is the purpose of granules?

Answer 19

contains toxic proteins that kills off pathogens once the pathogens come into contact with the toxic proteins

Question 20

What do histamines do and induce?

Answer 20

vasodilation to get more blood cells into circulation to help fight off infection | induce inflammatory proteins

Question 21

What does pus formation indicate?

Answer 21

dead neutrophils in tissue

Question 22

What are mast cells?

Answer 22

basophils in tissue

Question 23

What occurs when mast cells degranulate?

Answer 23

secretes all of the proteins stuck in them

Question 24

Are all granulocytes phagocytic?

Answer 24

yes

Question 25

What is the function of elastin and collagenase?

Answer 25

tissue remodeling

Question 26

What are 2 characteristics of monocytes?

Answer 26

larger than lymphocytes and granulocytes | big un-lobed round nucleus

Question 27

What are monocytes in the tissue called?

Answer 27

macrophages

Question 28

What are 2 things that monocytes can become?

Answer 28

macrophages and dendritic cells

Question 29

What are the 3 functions of macrophages?

Answer 29

help with tissue remodeling | clean up dead neutrophils | help destroy pathogens

Question 30

What are 4 characteristics of macrophages?

Answer 30

different sizes | lot of pseudopodia | large nucleus and stays in tissue

Question 31

What connects the innate and adaptive immune response systems?

Answer 31

dendritic cells as well as other PCs

Question 32

What do dendritic cells act as?

Answer 32

phagocytes

Question 33

How do dendritic cells help activate T-cells?

Answer 33

eat pathogen >>> process it >>> present part of it on its surface

Question 34

Where do dendritic cells stay?

Answer 34

in tissue

Question 35

What are antigen presenting cells (APCs)?

Answer 35

present pathogen peptides to T-cells

Question 36

What are the 3 APCs and which one is most potent for activating naiive T-cells?

Answer 36

Dendritic cells (most potent in activating naiive T-cells) | macrophages | B-cells

Question 37

What does MHC stand for?

Answer 37

major histocompatibility complex

Question 38

When do dendritic cells mature?

Answer 38

when they have eaten a pathogen

Question 39

What will dendritic cells do once they mature?

Answer 39

migrate out of the tissues into the lymphatic system to the lymph node where it will come into contact with T-cells

Question 40

What are the 3 major activities of APCs when they encounter pathogens?

Answer 40

secrete proteins = attract and activate other immune cells | eat pathogens, digest into peptides, present on their MHC class II molecules | express costimulatory molecules to activate T-cells

Question 41

What are the proteins that APCs produce?

Answer 41

cytokines and chemokines

Question 42

Which cells ONLY present MHC class II molecules?

Answer 42

APCs

Question 43

What are CD markers?

Answer 43

clusters of differentiation

Question 44

What are 2 characteristics of lymphocytes?

Answer 44

smooth nucleus, little cytoplasm (looks similar to monocytes)

Question 45

How will one be able to differentiate between B and T lymphocytes and innate lymphoid cells (ILCs)?

Answer 45

via Fluorescence-Activated Cell Sorting (FACS)

Question 46

What are the functions of cytokines?

Answer 46

activates, modulates, regulates other immune cells

Question 47

What is the function of chemokines? How do they carry out their function?

Answer 47

recruiting other immune cells via chemotactic proteins

Question 48

What do T-cells express?

Answer 48

CD4 and CD8

Question 49

What are T-helper (Th) cells?

Answer 49

helps immune response by activating or stimulating other immune cells such as B-cells

Question 50

What are T-cytotoxic (Tc) cells?

Answer 50

induces lysis

Question 51

Which T-cell expresses CD4?

Answer 51

T-helper cells

Question 52

Which T-cell expresses CD8?

Answer 52

T-cytotoxic cells

Question 53

Where do T-cells mature? (what organ)

Answer 53

thymus

Question 54

What does a cell expressing a CD3 marker on its surface indicate? What does it induce?

Answer 54

identifies that it is a positive (it expresses it) T-cell receptor | causes signal transduction to occur

Question 55

Where do B-cells mature?

Answer 55

bone marrow

Question 56

What is the receptor of B-cells?

Answer 56

immunoglobulins (antibodies)

Question 57

What does "cognate" mean?

Answer 57

specific/respective

Question 58

How do lymphocytes become effector lymphocytes?

Answer 58

lymphocyte leaves BM (B-cell) or thymus (T-cell) >>> contact with cognate antigen >>> becomes actived as effector lymphocyte

Question 59

What are plasma cells?

Answer 59

effector B-cells with Golgi and ER expanded since the cell has become an antibody-producing machine once activated

Question 60

What are natural killer (NK) cells part of: CLP or CMP?

Answer 60

CLP

Question 61

What recognizes virally infected cells?

Answer 61

NK cells

Question 62

What do B-cell receptors detect?

Answer 62

soluble antigen

Question 63

What do T-cell receptors detect?

Answer 63

peptide on MHC molecules

Question 64

Which receptor on T-cells bind to the MHC molecules?

Answer 64

CD4 and CD8

Question 65

Which MHC class molecule associates with Th cells?

Answer 65

MHC class II

Question 66

Which MHC class molecule associates with Tc cells?

Answer 66

MHC class I

Question 67

Which cells do Th cells only interact with and why?

Answer 67

APCs since they are the cells that only express MHC class II molecules which is what Th cells recognize

Question 68

Which cells express MHC class I?

Answer 68

all leukocytes (not RBCs)

Question 69

What cell in the BM that create the microenvironment to help B-cells mature into what they need to be?

Answer 69

stromal cells

Question 70

When do T-cells become either Th or Tc?

Answer 70

when they mature in the thymus

Question 71

How do the receptors interact between a T-cell and APC?

Answer 71

CD4 or 8 binds to MHC | T-cell receptor then recognizes the peptide as a result of that binding

Question 72

What are the costimulatory receptors on T-cells?

Answer 72

CD markers such as CD4 and CD8

Question 73

What does the term "left shift" refer to?

Answer 73

immature neutrophils (PMNs)

Question 74

Are there more of left shift or PMNs in circulation?

Answer 74

left shift

Question 75

What does the term "band" refer to?

Answer 75

nucleus has not fully become lobed/multi-lobed = looks like a band

Question 76

What is thymocyte?

Answer 76

immature T-cell

Question 77

What aspect of the T-cell is checked in the thymus?

Answer 77

affinity of the T-cell receptor

Question 78

What are the 2 primary lymphoid organs?

Answer 78

bone marrow and thymus

Question 79

What are the 3 secondary lymphoid organs?

Answer 79

lymph nodes | spleen | mucosal-associated lymphoid tissue (MALT)

Question 80

What are the 4 things that secondary lymphoid organs have an effect on lymphocytes?

Answer 80

act as area where lymphocytes: encounter antigens | become activated | clonal expansion | differentiate into effector cells

Question 81

What is the function of the lymph node?

Answer 81

checks lymphatic system for antigens and pathogens

Question 82

What is the function of the germinal centers in the lymph nodes?

Answer 82

B-cell undergoes second maturation

Question 83

Can one survive without a spleen? If so, what/are there any consequences?

Answer 83

yes but will be immunocompromised

Question 84

Where are the APCs found in the spleen?

Answer 84

marginal zone

Question 85

Where are the T-cells found in the spleen?

Answer 85

PALS (near marginal zone)

Question 86

What are Peyer's patches?

Answer 86

immune centers in the gut = GALT (part of MALT)

Question 87

What are 3 other MALTs?

Answer 87

gut (GALT) | nasal (NALT) | bronchial (BALT)