M103 T2 L5 Flashcards
What three cell types can a Common lymphoid progenitor cell differentiate into?
B lymphocytes, T lymphocytes
NK cells
What are the products of the myeloid progenitor cell? What does each produce? (BE.MEG)
basophil - basophils erythroid - erythrocytes megakaryocyte - platelets eosinophil - eosinophils granulocyte - neutrophils & monocytes
What are the four WBCs? (MEN.B)
monocytes
eosinophils
neutrophils
basophils
What WBCs are found in the tissue rather than in the blood?
mast cells, macrophages
fibroblasts
What is the function of tissue cells?
to secrete cytokines
Which lymphocytes are responsible for adaptive immunity?
B & T lymphocytes
Which myeloid cells are phagocytic? (NEMM)
neutrophils, eosinophils
macrophages, monocytes
Which cells are auxillary type cells?
basophils, mast cells
platelets (not strictly cells but still included)
Which cells are granululocyte type cells?
(BEN)
basophils
eosinophils
neutrophils
Why aren’t mast cells a granululocyte type cell?
bc this term is reserved for granulocytic cells that are present in the blood rather than in the tissue
What features do basophil cells have?
Lobed nuclei and heavily granulated cytoplasm
What percentage of lymphocytes are NK cells?
5%
What are the functions of basophils?
circulate in the blood and are recruited to sites of allergic reactions or ectoparasite infection
release pharmacologically active substances from their cytoplasmic granules
What do basophils do?
Express FCER1
can bind to allergen-specific IgE bound to the cell surface of basophils
this activates the basophil
causes degranulation of effector mediators - the granules are released to the outside of the cell to exert their biochemical effects
What are the features of eosinophil cells?
bilobed nuclei
granulated cytoplasm
What features do neutrophils have?
Multilobed nucleus
are very short lived so they are constantly being replenished
What is the function of neutrophils?
they are the first responders to infection
they are phagocytic and express enzyme myeloperoxidase and reactive oxygen species (are very toxic to pathogens)
What is the shape of a nucleus in a monocyte?
Kidney-shaped
What is the function of monocytes?
Blood-bourne phagocytes
Precursors to macrophages
Where are macrophages located?
in tissues
How do monocytes differ to macrophages?
macs are found in the tissue not in the blood or spleen
macs are 5-10 times larger than mons
macs contain many more organelles compared to mons
macs lifespan is much longer than that of mons
both are phagocytic
What features do cytokines have?
made up of small proteins or glycoproteins
have a low molecular weight (< 30 kDa)
secreted primarily by WBCs
What are the functions of cytokines?
messenger molecules of the immune system
help regulate immune effector cell development
paracrine signalling (act locally)
What are the functions of chemokines?
attract leucocytes
recruit monocytes and neutrophils to the site of infection
What are the four symptoms of inflammation? (HR, PS)
heat, redness, pain and swelling
What is the purpose of inflammation?
recruitment - to bring cells and molecules involved in host defence and repair to the site of infection / injury
What are three key components of the inflammatory response?
Blood vessels
Phagocytic leucocytes
Plasma proteins
What are the steps of the inflammatory response?
Blood vessels dilate, become more permeable
Circulating leucocytes migrate into tissue
Leucocytes are activated by the pathogen or by damaged tissue (injury)
Activated leucocytes destroy microbes and unwanted material
What is the time-frame like for acute inflammation?
it’s the initial, rapid response that happens in response to injury or infection
it develops very quickly, within minutes
doesn’t last very long - hours / days
Which cells predominantly mediate acute and chronic inflammation?
acute - neutrophils
chronic - mononuclear cells