Physiology of Normal White Blood Cells Flashcards
(82 cards)
1
Q
What does haematopoiesis mean?
A
- haemato = blood cells
- poiesis = creating something
2
Q
What is a hematopoietic stem cell?
A
- stem cell of bone marrow
3
Q
What are the 2 main categories that hematopoietic stem cells can differentiate into?
A
- myeloid progenitor cells
- lymphoid progenitor cells
4
Q
What are myeloid progenitor cells?
A
- cells able to differentiate into blood cells
5
Q
What are lymphoid progenitor cells?
A
- cells able to differentiate into lymphocytes
6
Q
What are the 4 categories of cells myeloid progenitor cells can differentiate into?
A
1 - erythrocytes
2 - mast cells
3 - megakaryocytes
4 - myeloblasts
7
Q
What are erythrocytes more commonly known as?
A
- red blood cells
8
Q
What do megakaryocytes differentiate into?
A
- platelets
9
Q
What do myeloblasts differentiate into?
A
- neutrophils
- basinophils
- eosinophils
- monocytes
10
Q
Monocytes are found in the circulation, once they move into tissues, what do they differentiate into?
A
- macrophages
11
Q
What are the 2 categories of cells lymphoid progenitor cells can differentiate into?
A
- large lymphocytes = natural killer cells (granular)
- small lymphocytes = T and B cells
12
Q
What are pattern recognition receptors (PRRs)?
A
- receptors on the cells of the innate immune system
13
Q
What 2 different types of molecules pattern recognition receptors (PRRs) are able to detect?
A
- pathogen associated molecular patterns (PAMP)
- damage associated molecular patterns (DAMP)
14
Q
Pattern recognition receptors (PRRs) are able to detect pathogen associated molecular patterns (PAMP). What are PAMPs?
A
- parts of pathogens not normally in the body
15
Q
Pattern recognition receptors (PRRs) are able to detect damage associated molecular patterns (PAMP). What are DAMPs?
A
- cells present peptides for PRRs to bind
- these peptides tell immune cells the cell is damaged
- cell is phagocytosed and recycled
16
Q
Do PRRs secrete cytokines upon coming into contact with PAMPs and DAMPs?
A
- generally no
17
Q
What locations in the body can PRRs commonly be found?
A
- skin
- epithelial cells
- mucosal cells
- vascular endothelial cells
- fibroblasts
18
Q
What are the 2 most common PRRs that we need to know about?
A
- toll like receptors
- C-type Lectin Receptors
19
Q
Are macrophages able to signal other immune cells?
A
- yes
20
Q
As a professional antigen presenting cell, what do macrophages act as the bridge between?
A
- innate and adaptive immunity
21
Q
Which major histochemical complex class do macrophages use to present antigens to the adaptive immune system?
A
- MHC-II
22
Q
What are toll like receptors?
A
- receptors on all leukocytes
- they alert the body to initiate an immune response
23
Q
Macrophages do no not initially produce cytokines as they try to deal with PAMPs and DAMPs themselves. When would they secrete cytokines?
A
- toll like receptors signal them to release cytokines
- generally when pathogen or damaged cell is too much for the macrophage to manage alone
24
Q
What are cytokines?
A
- peptides secreted by immune cells
- help cells communicate
25
What are the 3 most important functions of cytokines?
1 - mediate and regulate immunity
2 - mediate and regulate inflammation
3 - mediate and regulate hematopoiesis
26
Are all toll like receptors located intra or inter-cellularly?
- both
27
What is myeloid differentiation primary response protein MyD88 (MyD88)?
- a signalling protein within immune cells
28
What is the function of myeloid differentiation primary response protein MyD88 (MyD88)?
- MyD88 initiates intracellular pathway
| - increase inflammatory cytokines and inflammation
29
In addition to toll like receptors, macrophages have a number of other receptors. One of which is a lipopolysaccharide receptors. What are these receptors?
- receptors that recognises bacteria cell wall liposaccharides
30
In addition to toll like receptors, macrophages have a number of other receptors. One of which is a scavenger receptors. What are these receptors?
- receptors that bind with oxidised LDL
31
In addition to toll like receptors, macrophages have a number of other receptors. One of which is a opsonin receptors. What are these receptors?
- receptors able to recognised antibodies
- antibodies bound to pathogens
- signal to macrophage to phagocytose the pathogen
32
Do neutrophils have a long or short life span?
- short life span
33
What are the first immune cells on the scene in the innate immune response?
- neutrophils
34
What are chemokines?
- small cytokines
| - specifically attract immune cells to site of damage
35
Once neutrophils have reached the site of injury, chemokines are released. Where do these chemokines go to that can initiate the production and release of more neutrophils?
- bone marrow
36
IL-8 is a chemokine released to recruit neutrophils. Which cells are able to produce IL-8?
- macrophages
- dendritic cells
- endothelial cells
37
What microorganisms are neutrophils specifically effective at destroying?
- fungi
38
How do neutrophils phagocytose microorganisms?
- within phagosomes
| - use of reactive oxygen species
39
In addition to reactive oxygen species, what else can cells use to phagocytose microorganisms?
- low pH
| - lysosomal enzymes
40
Basinophils, eosinophils and neutrophils all contain granules and multiple nuclei. How can you distinguish between these cells?
- characteristics of the nuclei
| - staining
41
What are eosinophils especially effective at killing?
- parasites (worms)
42
Do eosinophils release cytokines or histamines?
- cytokines
| - signal to adaptive immune response
43
What type of immune response are basophils specifically involved in?
- type 1 hypersensitivity
| - IgE antibody binding
44
Do basophils release cytokines or histamines?
- both
- histamines when no infection
- cytokines when infection
- once bound to antigen/antibody complex
45
Histamines are released by basophils, what is their effect on the body?
- ⬆️ vascular permeability
46
Dendritic cells have an important role and act as the bridge between what?
- innate and adaptive immune systems
47
What are dendritic cells specific role?
- bind antigens
| - present on MHC-II to T cells
48
Where do mast cells mature?
- tissue after leaving circulation
49
Where are mast cells commonly found in the body?
- skin
- connective tissue
- mucosal epithelial cells of RT and GIT
50
Mast cells secrete histamines, what does this do to blood vessels?
- ⬆️ vasodilation
| - ⬆️ permeability
51
What immune response are mast cells commonly associated with?
- type 1 hypersensitivity
| - allergies
52
What are natural killer cells?
- a lymphocyte
| - similar to cytotoxic T cells
53
Are natural killer cells able to kill multiple types of cells, or a specific type of cell like cytotoxic T cells?
- multiple cells
| - anything with a non- self MHC-I antigen
54
What leukocytes are the main killers of bacterial infections?
- acute = neutrophils
| - chronic = monocytes
55
What immune are the main killers of viral infections?
- B and T cells
| - sometimes monocytes
56
What leukocytes are the main killers of parasitic infections?
- eosinophils
| - mast cells are activates
57
What leukocytes are the main killers of fungal infections?
- monocytes
58
What leukocytes are involved in type I hypersensitivity, called allergies?
- mast cells
- acute = basophils
- chronic = eosinophils
59
Cytokines IL-1, IL-6 and TNF-a are all pro-inflammatory cytokines. When released what do they do to the blood vessels?
- increase vascular permeability
60
Cytokines IL-1 and IL-6 are released by monocytes, dendritic and endothelial cells. What leukocytes to they recruit?
- neutrophils
61
Cytokines IL-1, IL-6 and TNF-a are all pro-inflammatory cytokines. When released what do they do to the body temperature?
- ⬆️ temperature
- cause fever
- harder for microorganisms to function
62
What important function do cytokines IL-12 and IL-18 have?
- act as bridge between innate and adaptive immunity
| - specifically T cells and natural killer cells
63
What is the granulocyte-macrophage colony-stimulating factor (GM-CSF)?
- glycoprotein that acts like a cytokine
| - stimulates haematopoiesis
64
What are the 5 common symptoms associated with inflammation?
```
1 - redness
2 - swelling
3 - pain
4 - heat
5 - loss of function
```
65
In an inflammatory response, what do mast cells and basophils release to cause vasodilation at the site of inflammation?
- histamines
66
For basophils to release histamines what do they need to recognise as part of their pattern recognition receptors?
- pathogen associated molecular patterns
| - disease associated molecular patterns
67
Once leukocytes have recognised inflammation, PAMPs and DAMPs, what cytokines are released?
- IL-1
- IL-6
- TNF-a
- IL-8 (neutrophil recruitment)
68
Once inflammation has begun and there is an increase in vasodilation and vascular permeability, what is needed to ensure leukocytes are able to bind with endothelial cells?
- cell adhesion molecules (CAMs)
69
What is the main role of cell adhesion molecules (CAMs)?
- help cells stick together
| - key for leukocyte and endothelial interaction
70
What are the 4 major families of cell adhesion molecules (CAMs)?
1 - selectins
2 - mucin like
3 - integrins
4 - immunoglobulin (Ig) superfamily
71
Inflammation is a good response to tissue damage and infection, but it can also be bad. What happens if there is too much inflammation?
- can cause sepsis
72
What are some common clinical symptoms of sepsis?
- fever
- tachycardia (⬆️ HR)
- tachypnea (⬆️ RR)
- hypotension
- organ dysfunction
73
What causes sepsis and is it dangerous?
- bacteria in the blood (septicaemia) (Gram + or -)
| - high mortality rate 90%
74
Which toll like receptor is heavily involved in sepsis?
- toll like receptor 4
75
In sepsis inflammation can cause subsequent damage to what?
- vascular endothelial cells
- ⬆️ fluid loss
- ⬇️ in BP
76
What is a key anti-inflammatory cytokine?
- IL-10
77
Which leukocytes secrete the anti-inflammatory IL-10?
- macrophages
78
How is MyD88 inhibited to stop inflammatory cytokines?
- pattern recognition receptors
| - shorter version of MyD88
79
What can be found in the the blood that is able to inhibit IL-1B and TNF-a?
- soluble receptors in blood
| - act as sponges to absorb IL-1B and TNF-a
80
What is the difference between atherogenesis and atherosclerosis?
- atherogenesis = development of plaque
| - atherosclerosis = hardening of arteries
81
Once a macrophage has phagocytosed the oxidised LDL, what does it become?
- a foam cell
82
Once the foam cell has reached its usefulness, what happens to it in the necrotic plaque?
- necrosis
| - releases it contents
