PHGY 209 Lecture Notes - Lecture 8: Hematopoietic Stem Cell, Yolk Sac, Jelly Doughnut
14 Nov 2016
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Document Summary
Wbcs are the only blood cells that are nucleated. Hematopoiesis: production of blood cells (pluripotent hematopoietic stem cell -> commited stem cell (lymphoid/myeloid stem cell)) Cytokines: substances (proteins/peptides) released by one cell, affecting activity of another cell (growth & development) Hematopoietic growth factors (hgfs): cytokines that influence proliferation & differentiation of blood cell precursors. All blood cells are derived from one type of multipotential hematopoietic stem cell. Injecting bone marrow stem cells can make all blood cell types. : 25 x 1012 / 5l) no subcellular organelles function: transport respiratory gases b/w lungs & cells shape: biconcave disk (jelly donut when squeezed; also think of a dumbell) Advantage: max. surface area, minimal diffusion distance (efficient o2 & Rbcs have no subcellular organelles! (e. g. nucleus, mitochondria ) Hemoglobin: a protein, contains iron and heme group. 4 heme groups attached to one rbc; so, one rbc can transport up to 4 oxygens at once.
