[W6] Haematopoiesis Flashcards
(19 cards)
What is haematopoiesis?
The process of blood cell production from stem cells in the bone marrow.
What two progenitor lines arise from haematopoietic stem cells?
Myeloid and lymphoid progenitors.
Where does haematopoiesis occur in adults?
Pelvis, sternum, vertebrae, ribs, heads of long bones.
What are primary lymphoid organs?
Bone marrow and thymus.
What are secondary lymphoid organs?
Lymph nodes, spleen, MALT (e.g., Peyer’s patches, tonsils).
What types of cells support haematopoiesis in bone marrow?
Stromal cells – macrophages, fibroblasts, adipocytes, endothelial cells.
What is red marrow?
Bone marrow actively producing blood cells.
What process occurs in the thymus?
T-cell maturation and selection.
What is thymic involution?
Shrinking of the thymus with age → reduced immune function.
What is the function of lymph nodes?
Filter lymph and activate T and B cells against trapped antigens.
Where are germinal centres found?
In secondary follicles of lymph nodes – sites of B cell proliferation.
What are the two main functions of the spleen?
Filter blood and mount immune responses to blood-borne antigens.
What are the red and white pulp?
Red pulp: filters blood, removes old cells
White pulp: contains immune cells (T and B cells)
What are M cells?
Cells that transport antigens from gut lumen to lymphoid follicles.
What antibody is secreted in the gut in response to antigen?
IgA
What is CFU-GEMM?
Progenitor for granulocytes, erythrocytes, monocytes, megakaryocytes.
What is erythropoietin (EPO) and where is it made?
Hormone that stimulates RBC production; made in the kidney.
What is thrombopoietin and where is it made?
Stimulates platelet production; made in the liver.
What is the estimated daily blood cell production?
~3.7×10¹¹ cells/day (~4 million/sec).
