Lecture Exam 3 Flashcards
Where is the development of blood forming tissues in the embryo?
starts in the yolk sac (mesoblastic phase), then transitions to the liver and spleen (hepatic phase), and finally to the bone marrow (myeloid phase)
Where is the development of blood forming tissues in adults?
Bone marrow
How long does mesoblastic hematopoiesis last in embryo?
hematopoiesis in the yolk sac usually occurs between 2-3 weeks of embryonic development and can last up to 8 weeks
How long does hepatic hematopoiesis last?
Hematopoiesis in the liver and spleen usually occurs 6 weeks after gestation
When does myeloid hematopoiesis start?
It can start as early as the 20th week after gestation
How does the hematopoietic system change from birth to adulthood?
Once myeloid hematopoiesis starts, it focuses mainly on red bone marrow and as you get older it turns into yellow marrow and lymph nodes; about 50% of adult’s bone marrow is yellow
How does cellularity relate to yellow and red bone marrow?
cellularity describes the density of hematopoietic (blood-forming) cells within the marrow space.
Yellow has less and Red has more
Where in the hematopoietic system should I target if I want to obtain a sample?
The 3 top cites to get a sample of hematopoietic tissue is the ribs, the pelvis, and the sternum
What is the exact order of maturing in blood cells?
Hematopoietic stem cells -> Progenitor cells -> Precursor cells -> Mature blood cells
What terms do we use when we are talking about the maturing sequence of blood cells?
Differentiation - totipotent (any cell type), pluripotent (can be most types of cells)
Commitment - they are fully committed to the type of cell they have been differentiated into
What are the stages of committed stem cells?
Hematopoietic stem cells (HSCs)
-> Common myeloid progenitors (CMPs) -> Granulocyte-monocyte progenitors (GMPs) -> Megakaryocyte-erythroid progenitors (MEPs).
What are the growth factors for stem cells?
Cytokines
Cytokines
messengers of the immune system
Apoptosis
cell suicide
Name the initiators of apoptosis
Bcl-2
Name the inhibitors of apoptosis
IAP
Aneuploidy
abnormal number of chromosomes in the cell and can lead to cancer
Name and describe the 4 phases of the genereal cell cycle
G0 - outside of the cell cycle
G1- cell growth and synthesis
S - DNA synthesis
G2 - second gap before mitosis
M - Mitosis (Karyokinesis) and Cytokinesis
What stages of the general cell cycle is happening during the interphase of mitosis?
G1, S, G2
Karyokinesis
Division of cell nucleus
Cytokinesis
Division of cytoplasm
Mitogens
a protein that initiates mitosis
What are the two major regulatory protein classes?
Cdk(s) and Cyclin(s)
What are cyclins?
complexed regulatory protein that includes D123, E, A, B
What are Cdks?
Cyclin dependent kinases that include Cdk 4, 6, 2, and 1
How are the two protein classes associated with each stage of the the cell cycle?
Through each stage there is a different combo of cyclins and cdks
Name the Cyclin CDK combination for G1
Cyclin D1, D2, D3 and CDK 4 and 6, Cyclin E and CDK 2
Name the Cyclin CDK combination for S stage
Cyclin A Cdk 2
Name the Cyclin CDK combination for Mitosis
Cyclin B, Cdk 1
What happens to the protein classes during the final regulation of the cell cycle?
Cyclin/Cdk are inhibited by proteins
What are the inhibtors of the cell cycle?
proteins (p) specific to stopping cyclin/cdk where the number of the protein indicates the molecular weight (in thousands)
What is the Bcl-2 Protein Family?
This family decided the fate of the cell. 6 prevent apoptosis (Bcl-d) and 14 are pro apoptosis (e.g BAX)
What does IAP mean?
Inhibitors of Apoptosis Proteins meaning they down regulate apoptosis
Caspases
cysteine protease enzyme that act as molecular scissors towards proteins so the proteins can be recycled and reused
Phosphorylation
a process where a small chemical group called a phosphate gets added to a protein and changes the behavior of the protein
dephosphorylation turns the protein back to normal function
Ubiquitin
a molecular tagger that marks proteins for recycling or helps regulate various activities within the cell. It’s a crucial player in maintaining the health and function of cells in your body.
APAF - 1
Apoptic pepridase activating factor
What popular disease can too much Bcl-2 cause?
Leukomeia
Whats the stem cell’s role in hematopoiesis?
Balancing proliferation, differentiation, and apoptosis
Hematopoietic precursor cells
HSC (stem), HPC (progenitor), Maturing cells
Asymetric division in stem cells
one daughter like the parent (self-renew) and the other different by leaving
Progenitor cells
cant self renew but they can differentiate
CFU-GEMM
Colony forming unit, granulocytes, erythroid, macrophage, and megakaryotecyte
T-cells
Involved in cellular immunity, directly attack infected or abnormal cells.
B-cells
Involved in humoral immunity, produce antibodies to neutralize pathogens.
Name the polypeptide chains present during hematopoeisis
Empryonic - Zeta chains, Epsilon chains
Fetal - gamma chains
Adult - Beta, alpha, delta chains
