Cells and Organs Flashcards
what is the most common leukocyte in the blood?
neutrophils (innate cell) - 50-70%
following this would be lymphocytes 20-40%
What are granulocytes? Where are they found?
granulocytes are innate cells which possess the ability to secrete granules. They are found in the circulation.
the three main granulocytes are
neutrophils
eosinophils
basophils
what does each do?
neutrophils –> most common, arrive to infection scene first. They perform phagocytosis of microbes
eosinophils –> recognize and phagocytose opsonized molecules (i.e. antibody coated parasites)
Basophils –> respond to allergies and parasites
all produce inflammation
t or f, monocytes are granulocytes
false –> they are the circulation equivalent of macrophages
what are mast cells?
they release histamine in allergic reactions. We take anti-histamine during these reactions. They also have a major role in expulsion of parasites
t or f, monocytes are ABC’s
true, monocytes will digest microbe and present them on MHC complexes.
explain briefly
neutrophil eosinophil basophil monocyte dendritic cell B cell T cell
innate: granulocyte
neutrophil –> most common circulation, phagocytosis
eosinophil –> recognize opsonized microbes
basophil –> from allergic rxn, and parasite detection
innate
monocyte –> circulatory ABC, phagocytosis
intermediate: dendritic cell: also an ABC and scaffold
adaptive
B cell –> antibodies i.e. humoral
T cell –> cell mediated
Explain where each dendritic cell is found
- Langerhan cell
- interstitial dendritic cell
- interdigitating dendritic cell
- circulating “”
- langerhan cells are found in the epidermis of our skin and mucosal membranes
- interstitial –> populate organ tissue
- interdigitating –> found in t cell area’s of secondary lymph tissue and the thymus
- circulating –> in vasculature (blood and lymph)
What are follicular dendritic cells? (4 points)
- these are NOT antigen presenting cells unlike most dendritic cells
- located in B cell follicles
- express high levels of complement proteins and Fc receptors
- can also bind opsonized antigens
t or f, follicular dendritic cells have arms which contain receptors. These bind antigens and help facilitate B cell activation.
true! follicular dendritic cells aren’t associated with T cells like all others.
t or false, Natural killer cells and Natural killer T cells are the same thing.
false.
NK cells are innate cells which kill foreign molecules
NKT cells have NK and T cell properties.
what is hematopoiesis?
formation of all kinds of blood cells
all blood cells start off as a hematopoietic stem cell. Cytokines are often the regulatory molecule that causes these to differentiate.
What does the hematopoietic cell differentiate into for
- innate cells
- adaptive
hematopoietic stem cells will become
innate –> myeloid progenitor
adaptive –> lymphoid progenitor
where does differentiation of stem cells to myeloid and lymphoid occur? Where does differentiation of these to other immune cells occur?
stems differentiate in bone marrow
myeloid and lymphoid differentiate in bone marrow once more and then in peripheral tissue.
where do dendritic cells come from?
large variety of cells –> note they are considered adaptive cells in this situation.
what duct returns all lymphatics?
thoracic duct places all lymph back into the blood near your neck.
what is the main force of lymph movement?
contraction of skeletal muscle
explain what primary lymphoid tissue is and secondary lymphoid tissue is.
primary = bone marrow where cells are made and the thymus where T cells develop
secondary =
the spleen - filters blood
lymph node - traps antigens from lymph
MALT, BALT, and GALT
what are MALT, BALT, and GALT
secondary associated lymph tissue
mucosal
gut
bronchial (respiratory)
what is a naive B or T cell?
a mature lymphocyte that has not yet been activated by antigen.
how do naive lymphocytes enter a lymph node?
- afferent lymphatics
- high endothelial venules (HEV)
what are high endothelial venules?
HEV are venules that allow lymphocytes to enter lymph nodes.
Explain the anatomy of a lymph node from outside to inside.
lymph nodes have afferent lymphatics bringing in lymphocytes and APC’s and efferent lymphatics taking them out.
outer cortex contains the germ line
para cortex containing mostly T cells
medulla contain plasma B cells.
Explain what is in the outer, para, and medulla of a lymph node.
outer cortex –> contains follicles where germ lines develop. this is mainly B cells, follicular dendritic cells, and macrophages.
para-cortex –> This is where T cells and interdigitating dendritic cells are found
medulla –> here plasma B cells that secrete antibodies are found.
why are plasma cells found in the medulla of the lymph node?
medulla is closest to circulation so antibodies can enter it.
true or false, the spleen filters lymph.
false, ONLY BLOOD
t or f, most lymphocytes visit the spleen in one day.. much more than the lymph nodes
true.
the spleen is number one site to trap blood borne microbes
What is the Red pulp compartment and white pulp compartment of the spleen?
Red pulp compartment -> removes old RBC’s
white pulp compartment -> activates lymphocytes
White pulp is made up of the
- marginal zone
- PALS
- follicles
explain each
marginal zone –> this separates the red and white pulps. Additionally, this is where antigens and microbes get trapped.
PALS –> DC transports the antigens from the marginal zone to the periarteriolar lymphoid sheath (PALS) which surrounds the spleen arterioles. When the DC cells come they activate T cells
Follicles –> contain follicular DC cells, B cells, and macrophages.
what is the trabculae?
structural material of the spleen.
what is the bulk of lymphoid tissue?
MALT
what are Peyers patches?
Peyer’s patches are sections in MALT, BALT, and GALT, that contain M cells. M cells deliver antigen to underlaying immune cells.
what antibody is m cells biased towards?
IgA production
true or false, secondary lymph tissue is organized to have specific area’s interact with antigen
true such as follicles of the spleen and lymph nodes which contain B cells, follicular dendritic cells and macrophages.
