Hematopoiesis Flashcards
What day/week does the hematopoiesis begin?
19th day or 2nd week of embryologic development
It lines the cavity of the yolk sac arise from mesodermal cells.
Primitive erythroblast
The remaining cells surrounding the cavity of the yolk sac and form the future blood vessels.
Angioblasts
A continuous, regulated process of blood cell production that includes cell renewal, proliferation, differentiation, and maturation.
Hematopoiesis
Primary site of Mesoblastic phase.
Yolk sac
What are the measurable amounts of hgb produced by primitive erythroblast?
Hgb portland, Gower-1, and Gower-2
The hepatic phase of hematopoiesis begins at what day/weeks?
4-5th gestational weeks or 2nd month
In this stage, the developing erythroblast signal the beginning of definitive hematopoiesis with a decline in primitive hematopiesis.
Hepatic phase
What is the major site of hematopoiesis during the 3rd month?
Liver
First fully developed organ in fetus, becomes the major site of T-cell production.
Thymus
Organ that produces B-cells?
Kidney and Spleen
The production of megakaryocytes, erythroblast, granulocytes, monocytes, lymphoid cells, hgb F, A and A2 begin during this phase.
Hepatic phase
Lymph nodes, spleen, thymus, and kidney contribute during this phase.
Extra hepatic hematopoiesis
Other name for Mesoblastic phase.
Yolk sac phase or Mesenchymal stage
These are aggregates of primitive cell.
Blood islands
2 compartments in Dualistic/Polyphyletic theory.
- Hemohistioblast - WBC(grabulocytes), RBC, Platelet
2. Tissue hemohistioblast - agranulocytes, T-cell & B-cell, Plasma cells
During this month, the Medullary phase begins.
5th month of fetal life
Major site if hematopoiesis by the end of 6th month.
Bone marrow
During this stage, mesencyhmal cells(type of embryonic tissue), EPO, G-CSF, GM-CSF, Hgb F, Hgb A and A2 can be detected.
Medullary or Myeloid phase
It consist of trabecular bone resembling a honey comb located within the cavities of cortical bones.
Bone marrow
How many percent of bone marrow does the children and adult contain?
Children - 4.5%
Adult - 1.5%
An active marrow and usually seen during infancy and early childhood
Red marrow
The process of replacing active marrow by adipose tissue (yellow marrow).
Retrogression
An inactive marrow composed primarily of fat cells/adipocytes.
Yellow marrow
In this age, yellow marrow become more abundant and begin to occupy spaces in long bones.
Between 5 and 7 years of age
Composed of extravascular cords that contain all developing blood lineages, stem & progenitor cells, adventitial and macrophages.
Red marrow
The father of stem cell discovered in 1961.
James Till and Ernest McCullohch
Are bone forming cells?
Osteoblasts
Bone resorbing cells
Osteoclasts
What are the functions of liver?
- Synthesize various transport proteins
- Stores mineral and vitamins
- Conjugate bilirubin from Hgb degradation
- Transport bilirubin to SI for eventual secretion
These are macrophages that removes foreign debris from blood circulation. Also responsible for protein synthesis.
Kupffer cells
Largest lymphoid organ in the body.
Spleen
Functions of the Spleen.
- Indiscriminate filter of circulating blood
- Vital but not essential for life
- Production of IgM antibodies and complement, both of which can be used to opsonize bacteria.
Location of spleen.
Beneath the diaphragm behind fundus of stomach in upper left quadrant of the abdomen
Composed primarily of vascular sinusoids and by cords of Billroth. And serves as an important scavenger.
Red pulp
Contains lymphocytes, macrophages, and dendritic cells that help coordinate the immune response and play roles in both innate and adaptive immunity.
White pulp
2 methods for removing senescent RBCs from the circulation:
- Culling - cells are phagocytosed with subsequent degradation of cell organelles.
- Pitting - remove inclusions/damaged surface membrane from circulating RBCs.
Bean shaped, 1-5mm located aling lymphatic capillaries.
Lymph nodes
Located above the upper part of the anterior mediastinum at about the level of the great vessels of the heart.
Thymus
