Test 1 Flashcards
Where is red marrow in adults? in kids?
Adult red marrow only in epiphysis and metaphysis of trabeculae’s osteons
Kids: everywhere in bones, all of their marrow
Where is hemoatopoetic activity in first month of fetal life?
months 2-6?months 8-9?
Which month does hematopoeisis start in the marrow?
First month of fetal life hematopoeisis: yolk sac
Months 2-6: liver and spleen
months 8-9: marrow… starts month 4
Where is yellow marrow in adults? in kids?
Yellow marrow in adults: diaphysis’s medullary cavity, middle of long bones
Kids: nowhere
Differentiate totipotent, pluripotent, multipotent, and unipotent stem cells
- Totipotent –differentiate into all tissues of embryo plus extra-embryonic tissue, Present very early in fertilized egg
- Pluripotent – differentiate into all tissues of embryo
- Multipotent – differentiate into cells of a given germ layer, Most “adult” stem cells, Like Hematopoietic stem cells
- Unipotent – differentiate into a single cell type, Like lymphoid progenerators that can generate into B/T/K lymphocytes
what are the 3 factors involved in maintaining hematopoietic stem cell pool?
3 factors needed to maintain Hematopoietic Stem Cells:
SCF
IL-3
BM stroma (Bone marrow stroma)
What causes differentiation of Hematopoietic stem cells to myeloid vs lymphoid precursor cells?
Hematopoitetic stem cell differentiation into Myeloid progenitor: SCF, IL3, GM-CSF
Hematopoitetic stem cell differentiation into Lymphoid progenitor: SCF, IL3, IL-7
What are the defects that can occur in hematopoiesis?
Hematopoietic stem cells are killed, replaced, or become malignant
What are the 3 types of Colony Stimulating Factors involved w/Hematopoietic Stem Cell differentiation? What do they bind to?
○ GM CSF = granulocyte macrophage colony stimulating factor
○ G CSF = granulocyte colony stimulating factor
○ M CSF = monocyte colony stimulating factor
They all bind to Kit receptor on the HSCs
What is Kit receptor? and what type of receptor is it? what does it do?
CD 117 = Kit receptor
Tyrosine kinase Type III receptor, sends signal to nucleus to activate HSC to survive, proliferate, and differentiate
receptor for stem cell growth factors (SCF) and colony stimulating factors (CSF)
What causes differentiation of Hematopoietic stem cells to erythrocytes vs megakaryocytes?
HSC to erythrocytes: EPO (erythropoietin)
HSC to megakaryocytes: TPO (thrombopoietin)
What are the 3 types of transient (acquired) defects in hematopoiesis?
Transient (acquired) hematopoietic defects
1) infection
2) maternal isoimmunization
3) premature birth, low # of RBCs
What is Fanconi anemia? inheritance? how does it present?
Fanconi anemia = aplastic anemia, affects all cell lines
Autosomal recessive
Chromosmal repair and stability proteins mutated
Presentation: short, strabismus, low set ears w/frequent infections +/- deafness, abnormal/absent thumbs
What is Diamond-Blackfan anemia? inheritance? how does it present?
Diamond Blackfan anemia = Erythrocyte mutation
Autosomal Dominant, and sporadic pedigrees
Defect in ribosome fx
Presentation: 50% have skeletal abnormalities, RBC aplasia, macrocytic anemia w/reticulocytopenia, snub nose
What is Kostmann syndrome? inheritance? how does it present?
Kostmann syndrome = neutrophil mutations
Autosomal Recessive
Mutation in G_CSF receptor
Presentation: predisposition to luekemia development and recurrent infections
What is Amegakaryocytic thrombocytopenia? inheritance?
Amegakaryocytic thrombocytopenia = megakarycyte mutation
Autosomal recessive and x-linked
What is Thrombocytopenia-absent radius (TAR) syndrome? how does it present?
Thrombocytopenia-absent radius (TAR) syndrome
presentation: Thrombocytopenia at birth, skeletal anomalies
What is the congenital hematopoietic defect that affects Erythrocyte development?
Diamond-Blackfan anemia
What is the congenital hematopoietic defect that affects Megakaryocyte development?
Amegakarocytic thrombocytopenia and Thrombocytopenia-absent Radius (TAR) syndrome
Order the WBCs from most numerous to least numerous
Never Let Monkeys Eat Bananas
Neutrophils > Lymphocytes»_space; Monocytes > Eosinophils > Basophils
Describe the order of development from hematopoeitc stem cell to erythrocyte
Which stage kicks out the mitochondria? the nucleus?
Which stage starts chromatin clumping?
HSC > myeloid precursor cell > Hemocytoblast > Proerythroblast > basophilic Erythroblast > Polychromatic erythroblast > Orthochromic erythroblast/Normoblast > Reticulocyte > Erythrocyte
Polychromatophilic erythroblast kicks out mitochondria
Orthochromic erythroblast/Normoblast kicks out nucleus to turn into Reticulocyte
Basophilic Erythroblasts start chromatin clumping
What is clinically significant about Basophilic Stippling of Erythrocytes?
What if there’s Howell-Jolly bodies?
Basophilic Stippling = toxic bone marrow injury IE megaloblastic anemia or lead poisoning (leads to lots of dots=condensed ribosomes/RNA)
Howell Jolly bodies = 1 or 2 dots, significant of spleen dysfunction or absence
What are Neutrophils significant for? why? (what do they do?) What interleukins are required for their differentiation?
What is a Left Shift in Neutrophils significant for? (what do they do?)
Where are most Neutrophils?
Neutrophils = acute bacterial infection, bc they phagocytize bacteria, debris, and dead tissue (collects and dies as pus) and degranulate
Need *IL6, GM-CSF, and *G-CSF to differentiate
Left shift = very sick person, marrow’s releasing immature neutrophils
Most neutrophils are in tissue
What are Eosinophils significant for? What do they do?What interleukins are required for their differentiation?
Eosinophils = allergies, parasite, cancer, bc they’re phagocytic for Ag-Ab complexes and neutrophils, attracted to inflammation sites by basophil/mast cell cytokines
Need *IL5, GM-CSF
Make inflammatory cytokines and granules, some break down our own tissue
What are basophils significant for? What do they do? What interleukins are required for their differentiation?
Basophils = maybe myeloproliferative disorders, inflammation, parasites, allergies… least common leukocyte
Need IL3, *IL4, GM-CSF to differentiate
Basophils enhance inflammation by arachidonic acid metabolite release, and release granules
What are mast cells significant for? What interleukin does it require for differentiation and growth? What is it blocked by?
What do receptor do they have and what do they bind?
Mast cells = allergies and Type I Hypersensitivity, requires SCF and *IL-4 to mature and grow
Mast cells blocked by anti-H1 (Diphenhydramine) or H2 (Cimetidine or Ranitidine)
Possess Fcε receptor, and bind IgE w/it
Differentiate mast cells vs basophils
Mast cells mature in the tissue site, as fixed in tissues, bigger than basophils, have 1000 granules/cell, granules 6x smaller than basophil’s, round nucleus
Basophils mature in bone marrow, aren’t fixed in tissues, smaller than mast cells, have only 80granules/cell, granules 6xbigger than mast cell’s, and bilobar nucleus
What are lymphocytes significant for?
Lympocytes = viral infection or lymph system disease
What are Monocytes significant for? Where do they differentiate, and what do they differentiate into? What do they do?
Monocytes = end of acute infection, some chronic infections (TB, endocarditis), Cronh’s and ulcerative Colitis, and Hodgkin’s
Circulating phagocytes then
They differentiate into macrophages in tissue
What do plasma cells do? What’s it significant for?
Mature lymphocytes (develop from Bcells), make and secrete Abs Significant for Multiple Myeloma
Describe what Fixation, Heat, and Storage artifacts look like of peripheral blood smears
Fixation: water contamination in methanol fixation -> refractile rings in erythrocytes
Heat: erythrocytes bud off and microspherocytes appear, get counted as platelets, can occur in burn victims
Storage: WBCs are fragile, forming smear cells (mushed), Neutrophil nuclei ‘round up’ and form homogenous round mass, RBCs undergo echnicytic change, making Burr cell
What is Hemotocrit? Why does it fall during pregnancy?
Hct = (RBC volume) / (plasma volume)
Pregnancy causes RBC mass to increase, but plasma volume increases more
Walk through Iron absorption steps from good ingestion to getting into an macrophage
1) Iron gets reduced by a reductase on the brush-border membrane of enterocytes to Fe2+
2) Iron enters enterocyte via DMT1 (aka DCT1)
3) In enterocyte, Fe2+ can get oxidized to Fe3+ by ferroxidase and stored on Ferritin OR can get out through Ferroportin, helped by Hephaestin that oxides it
4) in blood, Fe3+ travels around on Transferrin
5) Transferrin can dock on TransferrinReceptor1 on RBC and endocytosed, getting out via DMT1
6) RBCs can get ingested by macrophage
Fe2+ gets out via DMT1, and either stays in macrophage on Ferritin, OR gets out via Ferroportin, helped by Ceruloplasmin that oxidizes it
Walk through VitB12 absorption steps from ingestion to liver
1) B12 freed from food proteins by low pH (needs low pH)
2) B12 binds to R-factor, that’s in saliva
some B12 binds to IF that’s in gastric juices but bond isn’t as strong as w/R-factor
3) B12-Rfactor moved into small intestin
4) Pancreatic enzymes release B12 from Rfactor
5) B12 binds to IF
6) B12-IF gets absorbed into enterocyte brush border
7) Inside, B12 is freed and binds to Transcobalamin II
8) B12-transcobalamin II moves into blood
9) B12 stored in liver, released as needed by bone marrow
Walk through folic acid absorption, from ingestion to enterocyte
1) Folic acid in leafy greens, liver, some fruits (easily destroyed in cooking)
2) Folic acid broken down from pteromonoglutamic acid to pteromonoglutamate by brush border enzyme
3) Folic acid absorbed through carrier protein
4) Folic acid converted to THF (tetrahydrofolate), needed for purine and thymidine synthesis
VitB12 deficiency and Folic acid deficiency both show a build up in what?
What builds up only in VitB12 deficiency?
Lack of B12 and Folic Acid both lead to Homocysteine buildup
B12 deficiency also leads to MMA (methylmalmonic acid) buildup
no folic acid -> lots of homocysteine, no methionine
no B12 -> lots of homocysteine and MMA, no methionin or Succinyl CoA
What are the 2 Integral proteins in the erythrocyte membrane, and what do they do?
RBC Integral membrane proteins
1) Band 3: major integral protein, anion (Cl-) transport, links lipid bilayer to Ankyrin and protein 4.2 making vertical interactions
2) Glyphorin: provides (-) charge to cell surface
What are the 3 peripheral proteins of erythrocyte membrane?
RBC Peripheral Proteins
1) Spectrin: makes repeating 6unit lattice just below lipid bilayer surface, foundation of membrane skeleton making horizontal interactions
2) Ankyrin: couples spectrin lattice to Band 3 proteins making vertical interactions
3) Actin/Protein 4.1/Spectrin complex: more binding proteins
where in the erythrocyte lipid bilayer are the charged vs uncharged phospholipids more concentrated?
RBC lipid bilayer
more charged phospholipids in inner monolayer vs
more uncharged phospholipids outer monolayer
What stimulates kidneys to produce EPO?
Hypoxia stimulates kidneys to produce EPO
which haemopoetic cell lacks CD markers? why?
Lymphoid progenitor cells lack CD markers bc pre-Tcells migrate to thymus to mature, and pre-Bcells migrate to bone marrow to mature
Walk through lymphocyte proliferation from lymphoid progenitor cell to mature B/T cells
1) lymphoid progenitor cells divide into pre B/T cells after interacting w/ IL3+IL7/IL7
2) pre B/T cells must express heavy/beta chains, otherwise they’re destroyed
3) Pre B/T cells must complete their antigen receptor by expression the Light/Alpha chains
4) If their complete antigen receptor binds self too strong, destroyed through negative selection
If no self antigen recognized destroyed by failure of positive selection
If there’s weak self antigen recognition, B/T cell matures through positive selection!
T/F? B and T cells develop their antigen specificity in the absence of antigen
True! B and T cells develop their antigen specificity in the absence of antigen bc their -/+ selection is against self antigen
What are the gene coding regions on Bcell heavy (H) and light (kappa/lambda) chains?
After activation, Bcells only express what Ig on its surface?
Heavy: V, D, J
Light: V, J
Activated Bcells express only IgM as membrane molecule
What are the gene coding regions on Tcell beta and alpha chains?
Beta: V, D, J
Alpha: V, J
From what do NK lymphocytes differentiate from? What do NK lymphocyte recognize, and what do they do to the invaders?
NK lymphocytes differentiate from T lymphocyte precursors, but don’t require thymus for maturation
NK recognize the absence of HLA molecules like tumor cells or cells infected by viruses
NK lymphocytes have lysing granules or Fc receptors that help them participate in Ab dependent cell mediated cytotoxicity
What do the 5 types of CD4+ lymphocytes do?
Th1: helps CD8+
Th2: helps Bcells switch from IgM to IgE
Thf: helps Bcells switch from IgM > IgG + IgA
Th17: activates inflammation via cytokine secretion
Treg: down regulates other lymphocytes via IL10 and TGFbeta
What do Monocytes divide into?
Monocytes divide into Macrophages and Dendritic cells
What types of anemias cause an RDW increase?
nutritional deficiencies (b12, folate) cause elevated RDW Thalassemias cause elevated RDWs, but not as much
what’s the preferred site of bone marrow aspiration biopsy? additional options for adults or kids?
Preferred site = posterior iliac crest
Adults: sternum, or anterior iliac crest
infants: tibia
What’s the normal Erythroid:Granulocyte precursor ratio in bone marrow?
normal Erythroid:granulocyte 1:3
What are the key, regulatory enzymes for the pentose phosphate pathway, glycogen synthesis, and glycolysis?
Pentose phosphate pathway: G6PD
Glycogen synthesis: Glycogen synthase
Glycolysis: Phosphofructokinase
What moves glucose into erythrocytes? is it regulated by insulin?
GLUT1 moves glucose into erythrocytes… not regulated by insulin
What are the 4 essential products from glucose metabolism in erythrocytes, and what do they do?
4 essential products from glucose metabolism
1) NADPH: decreases ROS, from pentose phosphate pathway by reducing glutathione to recycle it
2) NADH: reduces methemoglobin’s Fe3+ to Fe2+, from glycolysis pathway
3) NAD+: needed to glycolysis cycle going, made by converting pyruvate + NADH → lactate + NAD(+)
4) 2,3-bisphosphoglycerate (2,3-BPG): allosterically regulates O2 binding to Hg from glycolysis offshoot pathway
What are the consequences of having a Pyruvate kinase deficiency G6PD deficiency* for erythrocytes? *most prevalent human genetic enzyme deficiency in world, confers malaria resistance
Pyruvate kinase deficiency means erythrocytes can’t make pyruvate, losing 50% of its ATP making ability (plus can’t convert pyruvate to lactate, so can’t make NAD+ and glycolysis grinds to halt)
G6PD deficiency means pentose phosphate pathway can’t occur, so buildup of ROS bc lack of glutathione destroys erythrocytes