Immunology 1 (13.1/13.2) Flashcards
what are the T cell receptors
alpha beta (95%) gamma delta (5%)
what do virgin t cells produce when activated?
cytokines
which cytokine is made in response to viruses or bacteria
Th1
which cytokine is made in response to parasitic or IgA infections
Th2
what are primary lymphoid organs responsible for and what are some examples of these organs
for the generation and maturation of lymphocytes
ex. thymus, bone marrow
what are secondary lymphoid organs responsible for
what are some examples of these organs
here lymphocytes congregate to carry out their functions
ex. they accumulate in locations like tonsils, ileum, appendix or lymph nodes
roles of the spleen
lymphatic organ for the circulation
reservoir for cells like monocytes
removes effete(disfunctional) erythrocytes from circulation
what is the purpose of reticulated epithelium in places like the tonsils?
to allow passage of lymphocytes through an epithelial layer
what are resident T lymphocytes in the thymus called
thymocytes
what is the function of hassall’s corpuscles and their location
function = mysterious found in medulla of thymus
the role of epithelioreticular cells (ERCs)
guard entrance to the cortex and the medulla of the thymus
create a perivsacular space between them and the medullary venules
what does the liver arise from
embryonic endoderm as the hepatic diverticulum (liver bud)
what does the cystic diverticulum give rise to
gall bladder and pancreas
T/F Liver has both exocrine and endocrine function, while pancreas only has exocrine function
False
both liver and pancreas have exocrine AND endocrine function
In adults, the exocrine outflow of the liver drains to
common hepatic duct
outflow to the duodenum is through what duct
common bile duct
what causes the sphincter of oddi to relax
CCK secretion in duodenum
the liver receives blood from
hepatic artery (from systemic circulation) and hepatic portal vein (majority of blood from here)
blood leaves the liver via
hepatic vein which joins inferior vena cava to return to heart
hepatic (or classical) lobule is centered around
central veins
-hepatic lobules usually hexagonal (vertices are portal triads)
portal lobule is centered around
portal triad
-portal lobule should be triangular (3 vertices are central veins)
hepatic acinus corresponds to
one incoming central artery and its drainage to two central veins
-diamond shape (two vertices are 2 closest portal triads across one axis, w 2 vertices of central veins across the other axis)
what must blood transit through to get from portal triad to central vein
hepatic sinuses
space of disse function
hepatocytes have access to plasma components
kupffer cells in sinuses are
resident macrophages
what do hepatic stellate cells generate
collagen in pathological state
what is the exocrine product of the liver
bile
where is bile secreted into
bile canaliculi
what are bile ductules lined with
cuboidal cholangiocytes
the liver is largely surrounded by
CT of Glisson’s capsule except where adventitial to the gall bladder
antigens that make it to the liver make a
tolerance response from the immune system
cell that represents the largest macrophage population in the body
kupffercells
what organ makes the majority of circulating immune system proteins
liver
what do liver transplants show
a degree of immunotolerance not seen in other organ transplants
they protect other upstream transplants
what viral diseases take advantage of the liver’s unique immune system to persist in the body
hepatitis B and C
where does the PHSC (pluripotential hematopoietic stem cell) function in adults
bone marrow
megakaryocytes produce
platelets
megakaryotes undergo endomitosis which is
chromosome duplication without cell division
Paget’s disease results from
imbalance in rates of bone formation and bone resorption
what are the abnormal morphological findings in pagent’s disease
- osteoclasts are abnormal
2. there shouldn’t be CT, there should only be bone or marrow
where are lymphocytes born and where do they enter circulation
the marrow and enter circulation at marrow sinuses
the similarity between B cell development in birds and mammals is that
initial B cell development and specification happens in the bone marrow
the difference between B cell development in birds and mammals is
the final stage of B cell development in birds requires that it goes through another organ called Bursa of Fabricius (near rectum)
- bursa is prominent in young bird but reduces with age which parallels with decline in B cell production
- mammals don’t have bursa but similar system for T cells which develop in marrow, enter circulation briefly, then go into thymus where fully mature
where are t cells born
marrow
the thymus is situated in the
mediastinum
-adventital area bn chest wall, parietal pleura, spine, and parietal pericardium
what happens to the thymus with age
it involutes (curves in) so much of the volume of the organ is replaced by adipocytes
thymocytes are
immature lymphocytes that is acquiring t cell receptors and the ability to bind non self MHC molecules
most common cell in the thymic cortex are
thymocytes
distinctive feature of the thymic medulla
hassall’s corpuscles which are sheets of squamous epithelioreticular cells (ERCs)
what comprises medullary ERCs
cytokeratin
involution occurs in what two structures
bone marrow and thymus
but bone marrow involutes before thymus
what is involution
the replacement of parenchymal cells with stromal adipocytes
when the bone marrow is dominated by adipocytes it’s called
yellow marrow
ideal bone marrow biposy from
red marrow target bc it has mostly hematopoietic cells
where is red marrow found in adults
ends of long bones, vertebral column, pelvis
where is the preferred biopsy site for marrow
crest of the ilium
functions of the liver
- modifications of blood-borne substances (intracellulary in hepatocytes)
- make bile to be sent to duodenum to prepare fats for digestion by enzymes
space of disse located
located bn sinus endothelium and hepatocyte
what is the connective tissue supporting the hepatocytes made up of mostly and what stain can be used to see them
reticular fibers
in a silver stain
what stains for kupffer cells
supravital staining
periportal means
affecting the cells around the portal triad
-zone 1 of hepatic acinus
pericentral
affecting the cells around the central veins
-zone 3 of hepatic acinus
which zone of the hepatic acinus is closest to inflow
zone 1 which has portal triads on the vertices
which zone of the hepatic acinus is closest to outflow
zone 3 which has central veins on the vertices
