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52 Cards in this Set

  • Front
  • Back
What is hematopoiesis?
generation of all blood cells
What cells are capable of differentiation?
stem cells
Where does hematopoiesis begin?
in the embryonic yolk sac
When do stem cells migrate from the yolk sac to the liver and spleen?
during the 3rd month of gestation
When does bone marrow take over hematopoiesis?
after the 7th month of gestation
What happens to hematopoiesis in adults?
long bone marrow fills in with fat and hematopoiesis occurs in the flat bones
What two pathways can hematopoiesis take?
1. Myeloid
2. Lymphoid
The myeloid progenitor pathway leads to the development of what cells?
neutrophils, eosinophils, basophils, dendritic cells, mast cells, and macrophages
The lymphoid progenitor pathway leads to the development of what cells?
T cells, B cells, and NK cells
The erythroid progenitor is another pathway that hematopoiesis can take. What cells are developed from this pathway?
erythrocytes and platelets
What transcription factor leads to the erythroid, myeloid and lymphoid lineage?
If something happens (such as a mutation) to the GATA-2 gene during embryogenesis, what will happen to that fetus?
What transcription factor leads to just the lymphoid lineage? What happens if there is a mutation in this gene?

the animal/human will be born, but will die early b/c they are susceptible to infections
What is the definition of apoptosis?
programmed cell death
What is the difference between apoptosis and necrosis?
apoptosis is normal, necrosis is not normal
What function and role in apoptosis does the bcl-2 gene have?
function - prevents apoptosis

role - inhibits apoptosis
What function and role in apoptosis does the bax gene have?
function - opposes bcl-2 gene

role - promotes apoptosis
What function and role in apoptosis does the Fas gene have?
function - induces apoptosis

role - initiates apoptosis
What information do CD markers give?
give information about the lineage or maturity of lymphocytes
Are BCRs and TCRs made before or after the cell encounters an antigen?
What is the site on BCRs and TCRs called that binds antigen?
antigenic determinant or epitope
Successful binding of the antigen receptor to the epitope results in what?
stimulation of the cell to enter the cell cycle and go through mitosis repeatedly leading to the development of a clone of cells with the same antigen receptor
How do BCRs and TCRs differ? (3 ways)
1. their structure
2. the genes that encode them
3. the type of epitope to which they bind
CD8 T cells bind epitopes that are part of which type of MHC?
Natural killer cells are specialized to kill which types of target cells?
host cells that are infected with virus or that have become cancerous
How do NK cells kill?
by exocytosis of granules that contain perforin and granzymes
Do NK cells have to develop into a clone of identical cells like B and T cells do?
NO, NK cells are preprogrammed to recognize their targets
Since NK cells respond rapidly, which type of immunity do NK cells provide?
innate immunity
Are NKT cells the same as NK cells?
NO, NKT cells are T cells with an alpha/beta TCR, but they also express some of the cell surface molecules of NK cells
NKT cells secrete large amounts of what?
IFN-gamma, IL-4, or IL-13
NKT cells defend against some infectious agents. What else are NKT cells implicated in protecting against?
autoimmune diseases, graft rejection, and tumors
What cells are in the bloodstream for approximately 8 hours and then migrate to the tissues to become what other type of cells?
mononuclear cells (monocytes) are in circulation then migrate to the tissues to become macrophages
What are some morphological differences between monocytes and macrophages?
monocytes have a smaller nucleus and fewer lysosomes than macrophages

macrophages have pseudopodia to help the cells move and engulf Ag; also have phagolysosomes
What are the tissue specific macrophages in the following body locations
1. gut
2. lung
3. liver
4. connective tissue
5. kidney
6. brain
7. bone
1. intestinal macrophages
2. alveolar macrophages
3. kupfer cells
4. histiocytes
5. mesangial cells
6. microglial cells
7. osteoclasts
What adheres well to macrophages and what adheres poorly to macrophges?
complex Ags adhere well

isolated proteins and encapsulated bacteria adhere poorly
What are the most abundant granulocytes?
Give some characteristics of neutrophils.
1. live for a few days
2. first at the site of inflammation
3. move into tissue by extravasation initiated by chemotactic factors (clotting factors and T helper cells)
4. high levels of glycogen
5. alot of granules that kill bacteria
Describe eosinophils.
act in defense against parasite infections and allergies

Describe basophils.
not phagocytic

plays an important role in some allergies

secrete pro-inflammatory mediators
Describe mast cells.
found in many tissues

histamine containing granulocytes
Describe dendritic cells.
aka Langerhans cells

First cells of the immune system to be discovered

found everywhere except the brain

versatile in their ability to capture Ag

phagocytic or pinocytic

found predominantly in skin
Where are follicular dendritic cells found and what do they help?
found inside lymph nodes

help B cells
What occurs in primary lymphoid tissue? in secondary lymphoid tissue?
primary - where maturation of immune cells occur

secondary - provide sites for mature immune cells to interact with Ag
What organs are considered primary lymphoid tissues? secondary lymphoid tissues?
primary - thymus, bone marrow

secondary - lymph nodes, spleen, MALT
Where does all returning lymph go?
into the thoracic duct to left subclavian vein; however, the right side of the head and right arm lymph goes into the right lymphatic duct and right subclavian vein
The thymus is divided into 2 lobes-what are they called?
1. Cortex - packed with immature T cells

2. Medulla - shrinkage area, function declines with age
Failure of thymus development leads to what syndrome?
DiGeorge's syndrome
What are the 3 areas in lymph nodes called and what do they contain?
1. Cortex - mostly B cells, macrophages, dendritic cells

2. Paracortex - mostly T cells, dendritic cells with high levels of MHC II

3. Medulla - sparsely populated with Ab secreting plasma cells
Describe the 2 types of pulps in the spleen.
1. Red pulp - site of destruction of old/defective erythrocytes

2. White pulp - populated by lymphocytes and macrophages
What is the periarteriolar lymphoid sheath?
sheath that surrounds arteries in the spleen where alot of macrophages and lymphocytes are found
What is MALT populated with?
T cells, some B cells, plasma cells, and macrophages
What to do the following stand for:
1. gut-associated lymphoid tissue
2. bronchial associated lymphoid tissue
3. nost-associated lymphoid tissue
4. skin-associated
5. vascular-associated
6. cutaneous-associated