Cell physiology Flashcards
What is Hematopoiesis?
The production of all types of blood cells including formation, development, and differentiation of blood cells. Prenatally, hematopoiesis occurs in the yolk sack, then in the liver, and lastly in the bone marrow. In adults it occurs in the bone marrow and lymphatic tissues.
What are stem cells?
Stem cells are biological cells that can differentiate into other types of cells and can divide to produce more of the same type of stem cells. They are found in multicellular organisms.
Differentiation of stem cells can be divided into?
Totipotent (zygotic) Pluripotent (embryonic) Multipotent ( hematopoietic) Oligopotent (GIT) Unipotent (prostatic)
How is the life cycle of cells?
survival, proliferation, differentation, death
Two types of cell division?
Symmetric –> self renewal
Asymmetric –> self renewal + differentiation. (stem cells)
What is a stem sell niche?
Specific environment in bone marrow keeping the cells in a “stem cell state” (undifferentiated)
What is transdifferentiation?
conversion of a cell type present in one tissue into a cell type from another tissue without going through a pluripotent cell state.
What is myelopoiesis?
production of bone marrow and of all cells that arise from it, namely, all blood cells. –> erythropoiesis, thrombopoiesis, granulopoiesis
What is lymphopoiesis?
Lymphopoiesis is the process in which lymphocytes (B cells, T cells and NK cells) develop from progenitor cells. B cell lymphopoiesis is completed in the bone marrow, whereas T cell lymphopoiesis occurs in the thymus.
What is hematopoietic environment?
stem cells + niche
cytokines (GF, IL)
vitamines (B4,6,12, vit-c)
hormones (erythropoietin, thrombopoietin)
What are the advantages of the biconcave disc shape in mammalian erythrocytes?
30% larges surface for oxygen diffusion
travel easy into small cappillaries ( small, without nuclei)
