Lecture 18 - White Blood cells Flashcards
cellular contents of white blood cells
contain cell organelles, nucleus and DNA (unlike erythrocytes)
white blood cells reach all areas of the body by?
moving out of blood capillaries, into the tissues, forming the interstitial fluid, which then returns to the blood via the lymphatic system
leukocytes derive from…?
hemopoitic stem cells
what happens when a b-cell recognises an antigen?
the cells multiply and transform into plasma cells, which make the antibodies specific to that antigen
name all 5 leukocytes
Lymphocytes (B + T) (20%), Basophils, Eosinophils, Neutrophils (70%), Monocytes (8%)
which WBC is pictured here?
lymphocyte
birth and life of monocytes?
develop in red bone marrow and circulate in the blood for ~5-8 days.
agranular leukocytes are…
monocytes and lymphocytes
basophils largely associated with?
intensify allergic reaction (histamine) very similar function to mast cells
which cells are phagocytes?
neutrophils and macrophages (not a blood cell). Also B-cells
who discovered phagocytes?
Metchnikoff
How does the macrophage destroy bacteria?
phagocytosis - engulf and digest.
what is the general function of lymphocytes?
process and store information about possible infections
which blood cell is the precursor to osteoclasts?
monocytes
what do macrophages identify?
crude features of pathogens, or bound antibody
Mast cell function?
release histamine during inflammatory and allergic reactions
name the granular leukocytes
Basophil, Eosinophil, neutrophil. All have visible granules in their cytoplasm
3 processes antibodies carry out, enhancing phagocytosis
- neutralisation (blocks viral binding sites, coats bacteria) - agglunation (antigen-bearing particles) - precipitation (of soluble antigens)
flow of lymph?
much slower than blood flow, series of valves prevent lymph flowing backwards
what are MHC class 2 molecules?
surface molecules on macrophages and B-cells, to which internalised proteins (antigens) from the digestion of bacteria bind.
what is the point of class 2 MHC-antigen complex
when the macrophages travel to the lymph nodes it allows the T-cells to read what’s inside.
Complement attack
Bacteria tagged with Ig destroyed by plasma MOLECULES (these molecules make up the complement system). The cell is lysed (bursts)
how do neutrophils identify their targets?
with generic receptors, made using information obtained through genetic inheritance. Only able to identify common bacteria features and can not adapt/ change if a new bacteria evolves
lymph node before and after infection of TB (for example)
- before: small B-cell clone (in lymph node) making antibodies for TB - after: B-cell clone expanded and producing more antibodies
litres of lymph in circulation
3L
which WBC is pictured here?
basophil
immune system repertoire =
all the different binding specificities of millions of different antibodies and similar membrane bound molecules
which WBC is pictured here?
eosinophil
2 types of t-lymphocytes and their function
- t-helper: assist and control b-cell expansion. Can instruct other cells to take action 2. t-cytotoxic: kill cells infected with virus (aka t-killer)
if an inbred mouse gets fried by radiation, what is the ONLY cell than can repair its immune response?
Lymphocytes
lymphatic system’s role in bootleg analogy
surveillance system
which WBC is pictured here?
neutrophil
which WBC is pictured here?
monocyte
lymphocytes identify?
anything non-cellular (anything that isn’t “you”) using antigen-receptor molecules on their membrane
how do macrophages come to be?
monocytes move out of capillaries into the infected tissue. Monocytes then develop into macrophages.
what do t-cells express?
antigen-specific t-cell receptor molecules
how do neutrophils do their thang?
neutrophils enter infection site and destroy bacteria, then die
what are b-cells genetically programmed to do?
encode a surface receptor for a particular antigen
another name for white blood cells
leukocytes
