LECTURE 2 Flashcards
What is Hematopoesis?
The production, development, differentiation and maturation of blood cells (erythrocytes, megakaryocytes and leukocytes) from multipoint stem cells
Where is the site of hematopoiesis?
- During embryogenesis + early foetal development = yolk sac then liver and spleen
- Throughout adulthood = bone marrow
What happens in asymmetric division?
One of the 2 multipotent stem cells will serve to renew the population of stem cells (self-renewal) while the other gives rise to a common LYMPHOID PROGENITOR CELL or COMMON MYELOID PROGENITOR CELL
[multipotent stem cells will differentiate in response to various cytokines and growth factors]
What does the common lymphoid progenitor cell give rise to?
- B lymphocytes
- T lymphocytes
- Natural killer cells
What do the common myeloid progenitor cell give rise to?
- Erythrocytes
- Megakaryocytes/Thrombocytes
- Mast cells
- Eosinophils
- Basophils
- Neutrophils
- Monocytes/Macrophages
- Dendritic cells
What is different about B lymphocytes and T lymphocytes?
B lymphocytes = remain in bone marrow and undergo development within the thymus
T lymphocytes = leave the bone marrow and undergo development within the thymus
What do B and T lymphocytes have in common?
Both have surface membrane receptors designed to bind to specific antigens
What is the natural killer cell?
A large granular lymphocyte that recognises tumour and virally infected cells through non-specific binding
What is a Myeloid cell?
Neutrophil or Polymorphonuclear cell
FUNCTION = phagocytic activity aimed at killing extracellular pathogens
What is a Plasma cell?
Terminally differentiated B lymphocyte that secretes antibodies
What is a Natural killer cell?
Kills virally infected cells and tumour cells
What is a Monocyte?
Precursor of tissue macrophage
What are the functions of Macrophages and Dendritic cells?
- Phagocyte
- Professional antigen presenting cell
- T-cell activator
