Immune system - week 7 Flashcards
which is the most predominant type of granulocyte in the blood?
neutrophil
at which site would you expect to find a neutrophil? are they phagocytic?
at sites of acute inflammation, yes
what does a neutrophil look like?
3 dark blobs in it
name the 3 types of granulocytes
neutrophil, eosinophil, basophil
name a phagocyte
macrophage
name 4 types of lymphocytes
t cell ,b cell, NK cell, mast cells
which granulocyte helps in defence against parasites
eosinophil
what are granules stained by on eosinophils? are the granules basic or acidic?
eosin, basic
what does an eosinophil look like?
2 dark blobs
name a granulocyte which is found in relatively low numbers in the blood?
basophil
granules of basophils are stained by ….. dyes and therefore contain ….. proteins
basic dyes, acidic
name 4 things which are in basophil granules
histamine, leukotrines, vasoactive mediators and platelet activating factor
what does a basophil look like?
lots of small dark spots - granules
which cell type can circulate then differentiate into a macrophage upon migration into tissues?
monocyte
what does a monocyte/macrophage look like?
one large/odd shaped dark blob
name the 2 types of t cell and what they do
cytotoxic - kill virus infected cells
helper t - activate b cells and macrophages
what can natural killer cells do?
detect and attack some virus infected cells
what do natural killer cells look like
one large, circular dark blob in middle
upon activation, what do mast cells secrete? what do they contain?
substances from their granules which affect vascular permeability, histamine and heparin
what do mast cells look like
small, fully dark blobs
what are the primary and secondary lymphoid tissues?
primary = thymus, bone marrow
secondary = lymphatics, tonsil, spleen adenoid, appendix
what are the 2 types of bone marrow and what are they involved in/made up of?
red = haematopoeisis
yellow = made of adipocytes
where in the mediastinum does the thymus sit?
superior and anterior mediastinum
when does the thymus begin to reduce in size and function?
after puberty
where does positive selection occur for t cells? what is positive selection?
cortex, selects for t cells capable of recgonising self MHC and antigens
what is negative selection of t cells and where does it happen in the thymus?
in medulla, eliminates t cells recognising self-peptide (dangerous)
name the 4 peripheral lymphoid organs
lymph vessels, lymph nodes, spleen, MALT
what is the name of the vessels in which lymphoid migrates to secondary tissues? what do they express here?
high endothelial venules, express adhesion molecules which lymphocytes bind to
what is the name of the duct in which the lymph vessles empty to the left venous angle? between which 2 veins is this duct?
thoracic duct, internal jugular and subclavian
function of the lymph nodes? what gets trapped in lymph nodes?
filter lymph from tissues, antigen
where in the lymph node do HEVs enter?
paracortex
where in lymph nodes are b and t cells located?
b in primary and secondary follicles in cortex
t in paracortex
which 2 ribs is the spleen located posteriorly with?
left 9 and 11
what does the spleen rest on?
left colic flixure of large intestine
what does the spleen collect? what does it do to the blood?
collects antigen from blood to present to lymphocytes, filters blood removing ageing RBCs/immune complexes
what are the 2 distinct components of the spleen
red and white pulp
what does the red pulp of the spleen do? what does the white pulp do?
red - filtration/removing aged RBCs
white - packed with t and b and dendritic cells and sifts antigen from blood
where in the spleen are t and b cells located?
t in periarteriolar lymphoid sheath
b in a corona beyond sheath in a germinal centre
name 3 places where MALT are found under the epithelium
respiratory, GI and GU tracts
name the 4 GALTs
tonsils, adenoids, peyer’s patches, appendix
name the 3 types of tonsil and where they are located
palatine at back of mouth, tubal in the nasopharynx near opening to inner ear, lingual at base of tongue
what type of tonsil are adenoids? where are they located?
pharyngeal, high in the nasopharynx behind nasal cavity and soft palate
what is the line of defence against pathogens created by the 4 types of tonsils called?
waldeyer’s ring
why do tonsils swell?
when an immune cell in the tonsil recognises an antigen it begins to rapidly divide causing swelling
where are peyer’s patches located?
in the mucosa throughout the small intestine in the ileum particularly
which 3 things do peyer’s patches consist of?
primary and secondary follicles and T cell zones which lie deeper
which part of the large intestine is the appendix part of?
caecum
