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Immuno Exam 1 L3
Question | Answer |
---|---|
Hematopoiesis | Formation, development and differentiation of blood cells. How we go from stem cells in the bone marrow to every other cell we have |
What is the lineage of RBCs or Erythroid? | Common myeloid-erythroid progenitor (CMP) |
What is the lineage of Lymphoid WBCs? | Common lymphoid progenitor (CLP) |
What is the lineage of Myeloid WBCs? | Common myeloid-erythroid progenitor (CMP) |
CMP stands for? | Common myeloid-erythroid progenitor (CMP) |
CLP stands for? | Common lymphoid progenitor (CLP) |
Lymphoid lineage becomes? | Adaptive immune cells (T and B) |
Myeloid lineage becomes? | Innate immune cells |
How is it decided for cells to become erythroid, lymphoid or myeloid? | By differentiation of chemicals |
Hematopoiesis starts with? | Stem cells (hematopoietic and multipotent) |
Natural killer cells form __________ progenitor? | Lymphoid |
Mature blood cells have a short or long life span? Replaced by? | Short. Must be continuously replaced by stem cells therefore the ability to generate new blood cells is important |
Stem cells are produced in? | Hematopoietic organs. Found in bone marrow |
Prenatal hematopoiesis | • 1st: yolk sak; 2nd: liver (5 weeks); 3rd: bone marrow (mid-gestation) • PAS and AGM are blood islands in the yolk sac • Midway through gestation you start hematopoiesis in bone marrow |
By age 7, most hematopoiesis happens? | In large/long bones (red bone marrow transfers to yellow) |
Postnatal hematopoiesis | Occurs almost exclusively in the bone marrow, stem cells undergo multiple cells divisions AND differenciation, replaces cells that leave the blood stream/die/destroyed |
Bone marrow | A gelatinous, vascular connective tissue located in medullary cavity of long bones 1) all lymphocytes arise here 2) fully mature myeloid and lymphoid cells can return 3) supports hematopoietic stem cell renewal and differenciation |
Structure of bone marrow | Stroma = all tissues NOT involved in hematopoiesis, Extensive network of sinusoids, arteries and veins, Islands of hematopoietic cells - Hematopoietic cells in various stage of maturation |
Stroma of bone marrow | Is all the tissues not involved in hematopoiesis |
Where is bone marrow of adults found? | Along long and big bones like the femur, pelvis, sternum, and humeras |
Microenvironment in bone marrow | Where T/B cells or other cells are found within one concentated spot |
Medullary cavity? Components? | Where bone marrow is found. Endosteal nitche is concentration of cells and as they mature they move closer to the vascular nitche to go into circulation |
Best known hemotopoietic growth factors are? | Interleukins, colony stimulating factors, other cytokines |
Most hematopoietic growth factors are? | Glycoproteins |
Erythripoiesis | Production of red blood cells. Stimulated by decrease in oxygen |
Major regulator of erythropoiesis? | Erythropoietin (EPO). Stimulated by decrease in oxygen |
How do you know you need more RBCs? | When oxygen levels drop, signal goes to kidneys, kidneys make hormones erythropoietin which is sent to red bone marrow, marrow makes RBCs. Only make them when you need them. |
Erythroblasts= | Nucleated precursors. Major stop for differenciatoin, still have a nucleuos at this stage. |
Reticulocytes= | Still immature RBCs, take a day to mature… basically you kick out nucleous and make LOTS of room for iron and oxygen |
Order of maturation for RBCs? | Hematopoietic stem cell, erythroblast, reticulocyte, erythrocyte |
How do you know a reticulocyte is done maturing? | Theres no longer a nucleus in order to make room for iron and oxygen |
Granulopoiesis | Production of granulocytes |
Three typres of granulocytes | Neutrohil, eosinophil, basophil |
Once you turn into a ________ you are commited to becoming a granulocyte? | myeloblast |
steps of maturation for granulocyte? | Common myeloid progenitor, myeloblast, then into neu/eosin/baso |
Monopoiesis | Production of monocytes |
Steps of monopoiesis? | Start at common myeloid progenitor monoblast promonocyte monocyte (when we get tissue specific) |
Thrombopoiesis | Formation of platlets |
Steps of thrombopoiesis? | Common myeloid progenitor, megakaryblast, megakaryocyte (because it is large) |
1 megakaryocyte= ______ platelets? | 5000-10,000 |
Platlets main and strange function? | Blood clotting |
Platlets | 2-3 µm in diameter, Lifespan = 5-9 days, Function = blood clotting, Cell fragments from megakaryocyte, Each megakaryocyte = 5000-10000 platelets |
lymphopoiesis | generation of lymphocytes |
lymphocytes are generated from? | Common lymphoid progenitor cell (CLP) stem cell |
Where do B cell form and mature? | In bone marrow |
Where do T cell form and mature? | Form in bone marrow and mature in the cortex of the thymus |
Lymphopoiesis generates what in addition to lymphocytes? | Natural killer cells and dendritic cells |
Primary organs of the Immune system | Thymus and bone marrow |
Secondary organs of the immune system? | Lymph nodes, spleen, cutaneous and mucosa-associated lymphoid tissues, mucous membranes |
Another name for primary? | generative |
Thymus | A bilobed organ above the heart surrounded by a capsule and divided into lobules. Has a network of epithelial cells, dendritic cells and macrophages. Function decreases with age. Most concerned with T-cells and exposure to antrogens |
Lobules of thymus | Outer part of lobule is cortex and inner is medulla |
Involution | Decrease in function as we age. For immune system it is because we have most of the T-cells we need in circulation |
Thymus is where what matures? | Tcell deevlopment and maturation. Immature T cells (thymocytes) develop in specific microenvironments. T cells develop antigen receptors |
Name of immature T cells? | Thymocytes |
T cells develop _____ receptors? | Antigen |
Parts of a thymus | Cortex, medulla, Hassall’s corpuscle |
Cortex | Densely populated with immature thymocytes |
Medulla | Sparsely populated with mature thymocytes |
Hassall’s corpuscles | Tightly packed epithelial cells. Important for making signals to activate T regulating cells |
Main function of secondary immune organs | is when you take nieve B and T cells and expose them to antigens and make them truly mature |
travel of immune cells is guided by _________? | Chemokines |
Immune cells travel through ______ system and ________ system? | Blood and lymphatic |
_____________ is returned to the circulatory system by lymphatic vessels | Interstitial fluid |
Largest lymphatic vessel? Where does it enter? | Thoracic duct. Enters subclavian vein. Lymph from right arm and right side of head enters through right lymphatic duct, drains into right subclavian vein |
Location of most important lymph nodes? We have over how many? | Over 500. Neck, groin and underarms |
Name of vertebrate circulatory system | Cardiovascular system. Has three types of vessels |
Arteries | Carry blood away from the heart |
Capillaries | Convey blood between arteries and veins |
A bed of cappilaries is surrounded by lymphatic ___________? | Vessels |
Lymph node structure | Encapsulated and bean shaped. 3 regions: cortex, paracortex and medulla |
Cortex of lymph nodes | B cells, macrophages, dendritic cells |
Paracortx of lymph nodes | T cells, dendritic cells, where we start interaction with atigen |
Medulla of lymph nodes | Lymphocytes exit here, plasma cells secreting antibody |
Afferent vessel | Come into, enter |
Efferent lymphatic vessel | Exit from lymph node |
Where are B cells activated and differenciate into high-affinity antibody-secreting plasma cells? | Lymph nodes |
What connects both blood and lymphatic vessels? | Lymph nodes |
What is the first organized structure to encounter antigens? | Lymph nodes |
T cells browse MHC-peptide combinations presented by? | Antigen-presenting cells |
Difference between primary and secondary lymph follicles? | Primary look dense purple and have inactivate B-cells that haven’t been exposed to antigen. Secondary have a light colored germinal center and activated B-cells |
Primary follicle of lymph node | Unactivated lymphiod follicle and no germinal center |
Secondary follicle of lymph node | Follicle that is activated by antigen, ring of B-cells that surround germinal center (proliferating B-cells and T helper cells) |
What happens to a B-cell once it is activated? | Turns into a plasma cell and secrets a lot of antibodies |
Spleen structure | Encepsulated, projections form capsule trabeculae, red pulp and whtie pulp |
Red pulp of spleen | Get ride of damaged or destroyed RBCs, macrophages, red b/c of RBCs |
White pulp of spleen | Find all lymphocytes, surrounds branches of splenic artery, forms PALS (periarteriolar lymphoid sheath), primary follicles rich in B cells, white b/c of WBCs |
Where does blood enter the spleen? | Splenic artery. The ONLY entrance |
What does the spleen do? | Filters blood, traps blood-borne antigens, important insystemic infections |
Only difference between lymph nodes and spleen? | Spleen is strictly blood stream and lymph node is both blood and lymph |
MALT has the highest amount of _____ compared to spleen and lymph nodes | Plasma cells |
GALT, NALT and BALT | GALT=gut; NALT=nasal; BALT=bronchous |
Peyer’s patch | Found in MALT, 30-40 lymphoid follicles in same area, have M CELLS |
M-cells | Are responsible for transmitting antigen across the gut wall. Act as part of Peyer’s patches to stimulate gut mucosal immunity. Named for their microfolds. They engulf antigens and bring them inside the cells to find T/B cells |
Skin associated lymph cells | Keratinocytes, langerhans, and intraepidermal lymphocytes |
Keratinocytes | Secret cytokines that may induce local inflammation |
Langerhans cells | Skin-resident dendritic cells |
Intraepidermal lymphocytes | Mostly T cells |
Cytotoxic | Cytotoxic T-cell= secret enzymes and kill infected celsl (act a lot like NK) |
T regulating cells | T regulating cells= down regulate immune response (this way T-cells that are activated can start looking for B cells to activate) |
T helper cells | in between T and B cells, important for activation by secreting soluble antibodies |
Pathway of B/T cells in lymph nodes | B/T into lymph node through blood stream, into High Endothelial Venule, separate depending on chemotaxis, B towards follicle and T towards peri-cortex |
Pathway dendritic cells in lymph node? How does it interact with B/T cells and what do they do? | Antigen presenting dendrtic cell or macro come in through lymph vessels, interact with T cells in pericortex 1st, find Tcell & activate it, T cell moves towards follicle, T cell finds/activates B cell, B cell turns into plasma cell and secrets antibodies |
Mucosa-Associated Lymphoid Tissue (MALT) | organized along digestive, respiratory, and urogenital tracts that defend membrane surfaces; have Peyer's patches;Includes tonsils, adenoids and appendix; NALT,GALT,BALT |