Physiology of normal white blood cells Flashcards
Complete the diagram of haematopoiesis for lymphoid cells

Complete the diagram on haematopoiesis of myeloid cells

Name the 10 components of the immune system
- B cell
- T cell
- Large granular lymphocyte
- Mononuclear phagocyte
- Neutrophil
- Eosinophil
- Basophil
- Mast cell
- Platelets
- Tissue cells
Which cells make up adaptive immunity?
B cells and T cells
Which 7 components of the immune system are leucocytes?
- B cell
- T cell
- Large granular lymphocyte
- Mononuclear phagocyte
- Neutrophil
- Eosinophil
- Basophil
Which 3 components of the immune system are lymphocytes?
- B cell
- T cell
- Large granular lymphocyte
Which 7 components of the immune system are phagocytes?
- Mononuclear phagocyte
- Neutrophil
- Eosinophil
Which 3 components of the immune system are auxillary cells?
- Basophil
- Mast cell
- Platelets
Which 3 components of the immune system are granulocytes?
- Neutrophil
- Eosinophil
- Basophil
What is a normal leucocyte (neutrophil) count in adult?
7.3 x 103
Which 2 cells make up the majority of lymphocytes?
Which type of cell makes up 5% of lymphocytes?
B cells and T cells
Which lymphocytes do and do not have antigen specific receptors?
B cells and T cells DO have antigen specific receptors
NK cells DO NOT have antigen specific receptors
What is the morphology of basophils?
Lobed nuclei and heavily granulated cytoplasm
What is the function of basophils?
Function by releasing pharmacologically active substances from their cytoplasmic granules
Where do basophils circulate?
The blood
What sites are basophils recruited to and what is their role there?
Sites of allergic reactions or ectoparasite infection
Express FceRI
Allergen can bind to allergen-specific IgE bound to the cell surface of basophils causing degranulation of effector mediators
Complete the diagram of the morphology of a neutrophil

What type of cell is this?

Eosinophil
What is the morphology of eosinophils?
Have bilobed nuclei and granulated cytoplasm
Why are eosinophils motile phagocytic cells?
Can migrate from the blood into the tissues
Where are the majority of eosinophils located?
Tissues
Which sites in the body are eosinophils recruited too and what is their role there?
Recruited to sites of allergic reactions
Express FceRI upon activation
Granules containing toxins e.g. peroxidases
Attack parasites in GI, respiratory and genito-urinary tracts
Which cell is this?

Neutrophil
Which cell type is a polymorphonuclear cell?
Neutrophil
What is the morphology of neutrophils?
Multilobed nucleus
Where do neutrophils circulate?
Found in the blood
Which type of cell makes up 60% of circulating leucocytes?
Neutrophils
Where are neutrophils recruited to in the body and what is their role there?
Rapidly recruited to sites of infection/injury
- ‘First responders’ to infection
- Myeloperoxidase and ROS
When do numbers of neutrophils increased?
During bacterial infection
Which cell has a short lifespan of 8 hours - 4 days?
Neutrophils
Which cell is this?

Monocyte
What is the morphology of monocytes?
- Kidney-shaped nucleus
- Precursors to macrophages
What soluble mediators do B cells produce?
Antibodies
What soluble mediators do T cells, large granular lymphocytes and mononuclear phagocytes produce?
Cytokines
What soluble mediators do mononuclear phagocytes produce?
Complement
What soluble mediators do basophils, mast cells and platelets produce?
Inflammatory mediators
What soluble mediators do tissue cells produce?
Interferons and cytokines
Where are monocytes found?
- Reservoir of monocytes in the spleen
- Also circulate in bloodstream where they enlarge
What type of cell is a blood-bourne phagocyte?
Monocytes
Where and when do monocytes migrate?
Migrate into tissues approx. 1 day after release from the bone marrow
Which cell is tissue specific?
Macrophages
What is the morphology of macrophages?
5-10-fold larger than monocytes
Contain many more organelles compared to monocytes e.g. lysosomes
Where are macrophages located?
Found in tissues
Tissue-resident phagocytes
Which cell has a lifespan of months to years?
Macrophages
Complete the diagram on the morphology of a monocyte
Complete the diagram on the morphology of a macrophage
Which cells increase/activate in a bacterial infection?
Increased neutrophils (Increased monocytes in chronic infection)
Which cells increase/activate in a viral infection?
Increased lymphocytes; sometimes increased monocytes
Which cells increase/activate in a parasite infection?
Increased eosinophils + activation of mast cells
Which cells increase/activate in fungal infection?
Increased monocytes
Which cells increase/activate in allergy?
Increased basophils ( ncreased eosinophils in chronic phase)
Activation of mast cells
Where does recruitment of lymphocytes occur?
From the blood to tissues
Interaction of leucocytes with blood vessels is key to which process?
Recruitment
What are cytokines?
Low molecular weight (< 30 kDa) regulatory proteins or glycoproteins
What is the role of cytokines?
Act as the messenger molecules of the immune system.
Also assist in regulating the development of immune effector cells.
What type of signalling do cytokines undertake?
Generally act locally (paracrine signalling)
What are chemokines?
These are a type of cytokine that induce directed chemotaxis in local responsive cells
What is the role of chemokines?
Chemokines function mainly as attractants for leucocytes, recruiting monocytes and neutrophils to the site of infection
Name an important monocyte chemokine
MCP-1 – Monocyte chemotactic protein-1.
(Also known as CCL-2)
What is inflammtion and what is it characterised by?
- A response of vascularised tissue to infections and damaged tissue
- Characterised by heat, redness, pain and swelling
What is the purpose of inflammation?
Bring cells and molecules involved in host defence and repair to the site of infection/injury
Complete the diagram showing the 3 steps in inflammtion

What are the 3 components of the inflammatory response?
- Blood vessels
- Phagocytic leucocytes
- Plasma proteins (e.g. complement, antibodies)
What are the 5 steps of the inflammatory response?
- Blood vessels dilate
- Blood vessels become more permeable
- Circulating leucocytes migrate into tissue
- Leucocytes are activated
- Activated leucocytes destroy microbes and unwanted material
Describe the difference between acute and chronic inflammation -
Duration
Development
Cells
Resolution
ACUTE -
- Initial, rapid response
- Develops within minutes
- Lasts hours – days
- Predominantly mediated by neutrophils
- Resolves once stimulus is removed
CHRONIC -
- Lasts weeks – months
- Predominantly mediated by mononuclear cells (macrophages, lymphocytes)
- Tissue destruction
- Attempts at healing (fibrosis)
Complete the diagram on the 3 steps of recruitment of monocytes to the site of inflammation

What are the 2 types of contact between endothelium and circulating cells?
- Initial contact: P-selectin and E-selectin on endothelium recognised by oligosaccharides (sulfated sialyl-Lewisx ) on leucocytes
- Tighter adhesion: intercellular adhesion molecules (ICAMs) on the endothelium recognised integrins on leucocytes
What is the role of MCP-1 in monocyte recruitment?
Adhering monocytes are stimulated by MCP-1 to cross the endothelium and lodge in the intima
What is activated endothelium a requirement for?
Inflammation
What 6 processes occur when adherent/activated platelets recruit and inflame monocytes?
- Chemotaxis
- Thrombosis
- Proteolysis
- Differentiation to macrophages
- Activation
- Adhesion
What type of cells can recognise, ingest and destroy many pathogens?
Phagocytic cells
How do phagocytic cells recognise pathogens?
These cells recognise pathogens damaged host molecules by means of cell surface receptors that can discriminate between the surface molecules displayed by pathogens and host cells.
These receptors can also recognize damaged host molecules
Name 3 pattern recognition receptors
Macrophage mannose receptor
Ligand: Conserved carbohydrate structures
Scavenger receptors
Ligand: anionic polymers, acetylated and oxidised LDL
Toll-like receptors (TLRs)
Ligand: range of ligands for various TLRs
Describe what is happening at 1,2 and 3 in phagocytosis
- Occurs via actin-based mechanism and interaction with various cell surface receptors
- Foreign particles internalized to form phagosomes
- Fusion of phagosomes with lysosomes leads to formation of phagolysosomes where foreign particles are enzymatically degraded
What is opsonisation of pathogens?
Coating pathogen with circulating receptors
Which proinflammatory cytokines are released from activated macrophages?
IL-1β
TNF-α
IL-6
Complete the diagram on activation of macrophages by pathogens

What is atherosclerosis?
Build-up of plaque in lining of arteries
What process is this?

Atherosclerosis
What 3 areas of pathogenesis is involved in atherosclerosis?
- Endothelial cell dysfunction
- Inflammation (mediated by monocytes/macrophages)
- Dysregulation of lipid metabolism
What is atherogenesis?
Development of atherosclerotic plaque
What is the trigger for atherogenesis?
Damage of endothelium & deposition of lipids
Complete the diagram on atherogenesis