Lecture 16 Hematopoiesis Flashcards
What is a multipotent stem cell?
Multipotent cells give rise to different cell types of a given lineage (adult stem cells).
What is a pluripotent stem cell?
Pluripotent cells give rise to all cells of the embryo and subsequently adult tissues (embryonic stem cell).
What is a totipotent stem cell?
totipotent cells give rise to all cells of an organism, including embryonic and extraembryonic tissues (cells which support embryonic development).
Example: a zygote is totipotent
Which type of stem cell gives rise to all cells of an organism?
Totipotent Stem Cell
What type of stem cell gives rise to all cells of the embryo and subsequently adult tissues?
Pluripotent Stem Cells (Embryonic Stem Cells)
What type of stem cell gives rise to different ceel types of a given lineage?
Multipotent Stem Cell (Adult Stem Cell)
True or False:
Embryonic Stem Cells are derived from the inner-cell mass of the blastocyst.
True - embryonic stem cells are derived from the inner-cell mass of the blastocyst.
Can embryonic stem cells be induced from adult tissues?
Yes
Where can adult stem cells be harvested from within the body?
Adult stem cells are harvested from mature organs/tissues (bone marrow).
How many different cell-types must a cell be able to differentiate into to be classified as a stem cell?
At least 2
During what weeks of gestation are nucleated erythrocytes given rise to?
From 2-8 weeks of gestation.
During weeks 2-8 of gestation, where are islands of hematopoiesis (blood islands) found?
In the yolk sac wall.
True or False:
Leukocytes form during weeks 2-8 of gestation.
False - NO leukocytes form during weeks 2-8 of gestation.
In what organ does hematopoiesis first occur during weeks 8-28 of gestation?
Hematopoiesis first occur in the liver and then the spleen during 8-28 weeks of gestation.
When does hematopoiesis in the spleen typically cease?
normally ceases around the time of birth.
At how many months of gestation does hematopoiesis begin to occur in the red bone marrow?
6 months gestation to birth and beyond.
True or False:
Red Marrow is the source of all blood cells?
True
Identify a few of the 6 bones that are responsible for blood cell production in red bone marrow prior to puberty.
- skull
- ribs
- sternum
- vertebrae
- clavicles
- pelvis
- long bones
**After Puberty it is the same except for the long bones.
At puberty most red bone marrow is converted to yellow marrow, but where in the body is red bone marrow usually restricted to for hematopoiesis to continue occurring?
Sternum and Iliac Crests
What is the function of the stroma in bone marrow?
The stroma synthesizes and secretes hematopoietic growth factors.
What kind of cells are found in the stroma of bone marrow?
- Fibroblasts
- Reticular Cells
- Adipose Cells
- Endothelial Cells
What does the parenchyma of bone marrow consists of?
Parenchyma consists of various lineages of hematopoietic cells in different stages of differentiation.
What is the main function of the sinusoids in bone marrow?
Sinusoids in the bone marrow provide access for mature blood cells to move into the circulation.
*Sinusoids are endothelial-lined spaces that connect arterial and venous vessels.
What is a sinusoid?
Sinusoids are endothelial-lined spaces that connect arterial and venous vessels.
What makes up hematopoietic cords and where are they found within the bone marrow?
Hematopoietic cords are bands of parenchyma and stroma lying between the sinusoids.
What percentage of cells are synthesized via granulocytopoiesis?
60% of hematopoietic cells are through granulocytopoiesis.
Fill in the Blank:
Erythrocytopoiesis synthesizes___________percent of erythrocytes.
30%
What percentage of hematopoietic cells are produced through thrombocytopoiesis, monocytopoiesis, or lymphocytopoiesis?
10%
A patient presents to you in clinic with a persistent headache, post-bath pruritus, bone and join pain (specifically in the hip and rib area), and just all around fatigue. Up on receiving their blood work back you notice their ratio for total volume of cells in granulocytopoiesis to total volume of cells in erythrocytopoiesis is 1:5. You know right away what’s wrong with the patient and you diagnose them with what condition?
Polycythemia
What is the normal myeloid/erythroid total volume ratio?
3:1
What is the typical myeloid/erythroid total volume ratio in a patient that has been diagnosed with chronic myelogenous leukemia?
8:1
Which two multipotential stem cells are derived from a hematopoietic stem cell?
1) Myeloid Stem Cell
2) Lymphoid Stem Cell
Which two precursor cells types are derived from lymphoid stem cells? Also, where are each precursor found within the body?
1) T-cell precursor -> in the thymus
2) B-cell precursor -> in the bone marrow
True or False:
The plasma cell is derived from a B-cell in the thymus.
False - the plasma cell is derived from a B-cell in the bone marrow.
Natural killer cells are derived from what precursor?
T-cell precursor in the thymus.
The metamyelocyte is a maturing cell in the lineage that comes from a basophil CFU, which in turn is derived from a myeloid stem cell. What two cells can be derived from a metamyelocyte?
Basophil and Mast Cell precursor
Which CFU committed precursor is a neutrophil derived from?
Granulocyte CFU
The macrophage is derived from a monocyte, but from which committed precursor is a monocyte derived from?
Macrophage CFU
What are the only two cell types that are derived from myeloid stem cells that don’t become mature until they migrate into the peripheral tissue?
Macrophage and Mast Cell